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Signal transducers and activators of transcription 3 ( Stat3 ) is activated by cytokines and growth factors in lung cancers and regulates expression of genes implicated in cell growth , survival , and transformation . Previously , we found that mice with a deletion of the G protein-coupled receptor , family C , group 5 , member a ( Gprc5a ) gene develop lung tumors , indicating that Gprc5a is a tumor suppressor . Herein , we show that epithelial cells from Gprc5a knockout mouse lung ( Gprc5a(-/-) cells ) survive better in vitro in medium deprived of exogenous growth factors and form more colonies in semisolid medium than their counterparts from wild-type mice ( Gprc5a(+/+) cells ) . Stat3 tyrosine 705 phosphorylation and expression of several Stat3-regulated antiapoptotic genes were higher in Gprc5a(-/-) than in Gprc5a(+/+) cells . Both cell types secreted leukemia inhibitory factor ( Lif ) ; however , whereas Stat3 activation was persistent in Gprc5a(-/-) cells , it was transient in Gprc5a(+/+) cells . Lung adenocarcinoma cells isolated from Gprc5a(-/-) mice also exhibited autocrine Lif-mediated Stat3 activation . The level of Socs3 , the endogenous Stat3 inhibitory protein , was higher in Gprc5a(+/+) than in Gprc5a(-/-) cells , and expression of the tumor suppressor stabilized Socs3 . Inhibition of Stat3 signaling in Gprc5a(-/-) normal and cancer cells by the Janus-activated kinase 2 inhibitor AG490 or by a dominant negative Stat3(Y705F) increased starvation-induced apoptosis and inhibited colony formation . These results show that persistent Stat3 activation is important for the survival and transformation of Gprc5a(-/-) lung cells and suggest that the tumor suppressive effects of Gprc5a are mediated , at least in part , by inhibition of Stat3 signaling through Socs3 stabilization .
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20959490
|
The Ras-assocation domain family ( RASSF ) of tumor suppressor proteins until recently contained six proteins named RASSF1-6 . Recently , four novel family members , RASSF7-10 , have been identified by homology searches for RA-domain-containing proteins . These additional RASSF members are divergent and structurally distinct from RASSF1-6 , containing an N-terminal RA domain and lacking the Sav/RASSF/Hpo ( SARAH ) domain . Here , we show that RASSF8 is ubiquitously expressed throughout the murine embryo and in normal human adult tissues . Functionally , RNAi-mediated knockdown of RASSF8 in non-small-cell lung cancer ( NSCLC ) cell lines , increased anchorage-independent growth in soft agar and enhanced tumor growth in severe combined immunodeficiency ( SCID ) mice . Furthermore , EdU staining of RASSF8-depleted cells showed growth suppression in a manner dependent on contact inhibition . We show that endogenous RASSF8 is not only found in the nucleus , but is also membrane associated at sites of cell-cell adhesion , co-localizing with the adherens junction ( AJ ) component beta-catenin and binding to E-cadherin . Following RASSF8 depletion in two different lung cancer cell lines using alternative small interfering RNA ( siRNA ) sequences , we show that AJs are destabilized and E-cadherin is lost from the cell membrane . The AJ components beta-catenin and p65 are also lost from sites of cell-cell contact and are relocalized to the nucleus with a concomitant increase in beta-catenin-dependent and nuclear factor-kappaB ( NF-kappaB)-dependent signaling following RASSF8 depletion . RASSF8 may also be required to maintain actin -cytoskeletal organization since immunofluorescence analysis shows a striking disorganization of the actin- cytoskeleton following RASSF8 depletion . Accordingly , scratch wound healing studies show increased cellular migration in RASSF8-deficient cells . These results implicate RASSF8 as a tumor suppressor gene that is essential for maintaining AJs function in epithelial cells and have a role in epithelial cell migration .
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20514026
|
OBJECTIVE Lung cancer is a deadly cancer , whose kills more people worldwide than any other malignancy . SLUG ( SNAI2 , Snail2 ) is involved in the epithelial mesenchymal transition in physiological and in pathological contexts and is implicated in the development and progression of lung cancer . METHODS We constructed a lentivirus vector with SLUG shRNA ( LV-shSLUG ) . LV-shSLUG and a control lentivirus were infected into the non-small cell lung cancer cell A549 and real-time PCR , Western blot and IHC were applied to assess expression of the SLUG gene . Cell proliferation and migration were detected using MTT and clony formation methods . RESULTS Real-time PCR , Western Blot and IHC results confirmed down-regulation of SLUG expression by its shRNA by about 80% at both the mRNA and protein levels . Knockdown of SLUG significantly suppressed lung cancer cell proliferation . Furthermore , knockdown of SLUG significantly inhibited lung cancer cell invasion and metastasis . Finally , knockdown of SLUG induced the down-regulation of Bcl-2 and up-regulation of E-cadherin . CONCLUSION These results indicate that SLUG is a newly identified gene associated with lung cancer growth and metastasis . SLUG may serve as a new therapeutic target for the treatment of lung cancer in the future .
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23244088
|
BACKGROUND Cancer of the thyroid gland is rare in children and adolescents . A history of neck irradiation is a well-established risk factor for tumor development , and most previous reports focused on cases that were induced by radiation exposure . We present here a retrospective review of the clinical features , treatment , and long-term outcome of children and adolescents with papillary thyroid cancer ( PTC ) without a history of radiation exposure who were treated at our institution over a period of METHODS We retrospectively investigated 142 PTC patients without an irradiation history who were younger than 20years of age when treated from 1961 to 2005 ( 17 males and 125 females ; mean age=16.3±2.7years ; follow-up=21.8±12.0years ) . The clinicopathological results were evaluated using the medical records . Disease-free survival ( DFS ) and cause-specific survival ( CSS ) were assessed with the Kaplan-Meier method and compared with the log-rank test . Parametric analyses were performed using Student's t test and nonparametric analyses were performed using the Mann-Whitney U test . RESULTS At diagnosis , three patients had distant lung metastasis and 33 had gross neck lymph node ( LN ) metastasis . All patients were treated with surgery ( hemi/partial thyroidectomy in 45 patients , subtotal thyroidectomy in 85 , total thyroidectomy in 12 , no LN dissection in 50 , central compartment dissection in 20 , and modified radical neck dissection in 72 ) , and postoperative external beam radiation therapy was administered to 59 . Postoperative ablative therapy using I(131) was not performed in this series . Recurrence was found for regional LN ( n=25 ) , lung ( n=9 ) , remnant thyroid ( n=5 ) , and others ( n=4 ) . DFS and CSS at 40years were 74.1 and 97.5% , respectively . DFS was significantly worse in patients aged <16years with a family history of thyroid cancer , preoperative neck gross LN metastasis , maximum tumor diameter , and extrathyroidal invasion . Preoperative gross neck LN metastasis and distant metastasis at diagnosis were significant factors for CSS . No other factors contributed to DFS and CSS . When the clinical features of children and adolescents were compared , the incidence of preoperative gross neck LN metastasis and distant metastasis at diagnosis and tumors with a maximum diameter >10mm were significantly higher in the children group than in the adolescent group . DFS was significantly shorter in the children group than in the adolescent group , but no significant difference was found in CSS between these two groups . CONCLUSIONS The prognosis of PTC in children and adolescents is excellent , regardless of the extent of thyroidectomy and LN dissection . We recommend that only children or adolescents with preoperative gross neck LN metastasis and distant metastasis at diagnosis should be subjected to postoperative ablative therapy .
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22411092
|
OBJECTIVE To sort and identify side population ( SP ) cancer stem cells ( CSC ) in human prostate cancer ( PCa ) cell lines . METHODS Stem-like cells were isolated from five PCa cell lines Du145 , IA8 , LNCaP , TSU-Pr and PC-3 using FACS based on CD133+ CD44+ immunophenotype and SP in Hoechst staining . The in vitro growth pattern and tumorigenicity of SP stem cells were verified by soft agar colony-formation trial . LNCaP/SP cells were selected for further identification of stem cell properties using immunostaining , proliferation and invasion assay . Eventually , tumorigenicity and metastasis ability of LNCaP/SP were confirmed by xenograft experiments . RESULTS The percentages of CSCs of the CD133 CD44 + immunophenotype were extremely low in the five PCa cell lines . On the contrary , the percentages of the isolated SP cells were significantly higher in Du145 ( [ 0.15 +/- 0.02]% ) , IA8 ( [ 0.60 +/- 0.07 ]% ) , LNCaP ( [ 0.8 +/- 0.1]% ) and TSU-PrL ( [ 2.0 +/- 0.4]% ) , but none was detected in PC-3 . Besides , IA8/SP , LNCaP/SP and TSU-PrL/SP cells showed a significantly greater colony-forming efficiency than non-side population ( NSP ) cells ( P < 0.05 ) . Compared with LNCaP/NSP cells , LNCaP/SP cells exhibited high expressions of integrin alpha2 , Nanog , CD44 , OCT4 and ABCG2 , remarkably enhanced invasive and proliferative potentials in vitro , and markedly increased tumorigenicity and metastasis ( P < 0.01 ) . CONCLUSION SP sorting is more suitable than CD133+ CD44+ selection for enriching CSCs from PCa cell lines , and LNCaP/ SP represents a typical CSC population .
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23405783
|
TP53 mutations compromising p53 transcriptional function occur in more than 50% of human cancers , including pancreatic adenocarcinoma , and render cancer cells more resistant to conventional therapy . In the last few years , many efforts have been addressed to identify p53-reactivating molecules able to restore the wild-type transcriptionally competent conformation of the mutated proteins . Here , we show that two of these compounds , CP-31398 and RITA , induce cell growth inhibition , apoptosis , and autophagy by activating p53/DNA binding and p53 phosphorylation ( Ser15 ) , without affecting the total p53 amount . These effects occur in both wild-type and mutant p53 pancreatic adenocarcinoma cell lines , whereas they are much less pronounced in normal human primary fibroblasts . Furthermore , CP-31398 and RITA regulate the axis SESN1-2/AMPK/mTOR by inducing AMPK phosphorylation on Thr172 , which has a crucial role in the autophagic response . The protective role of autophagy in cell growth inhibition by CP-31398 and RITA is supported by the finding that the AMPK inhibitor compound C or the autophagy inhibitors chloroquine or 3-methyladenine sensitize both pancreatic adenocarcinoma cell lines to the apoptotic response induced by p53-reactivating molecules . Our results demonstrate for the first time a survival role for autophagy induced by p53-reactivating molecules , supporting the development of an anti-cancer therapy based on autophagy inhibition associated to p53 activation .
|
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23238993
|
This study aimed to analyze the role of endothelial progenitor cell ( EPC)-derived angiogenic factors and chemokines in the multistep process driving angiogenesis with a focus on the recently discovered macrophage migration inhibitory factor ( MIF)/chemokine receptor axis . Primary murine and murine embryonic EPCs ( eEPCs ) were analyzed for the expression of angiogenic/chemokines and components of the MIF/CXC chemokine receptor axis , focusing on the influence of hypoxic versus normoxic stimulation . Hypoxia induced an upregulation of CXCR2 and CXCR4 but not CD74 on EPCs and triggered the secretion of CXCL12 , CXCL1 , MIF , and vascular endothelial growth factor ( VEGF ) . These factors stimulated the transmigration activity and adhesive capacity of EPCs , with MIF and VEGF exhibiting the strongest effects under hypoxia . MIF- , VEGF- , CXCL12- , and CXCL1-stimulated EPCs enhanced tube formation , with MIF and VEGF exhibiting again the strongest effect following hypoxia . Tube formation following in vivo implantation utilizing angiogenic factor-loaded Matrigel plugs was only promoted by VEGF . Coloading of plugs with eEPCs led to enhanced tube formation only by CXCL12 , whereas MIF was the only factor which induced differentiation towards an endothelial and smooth muscle cell ( SMC ) phenotype , indicating an angiogenic and differentiation capacity in vivo . Surprisingly , CXCL12 , a chemoattractant for smooth muscle progenitor cells , inhibited SMC differentiation . We have identified a role for EPC-derived proangiogenic MIF , VEGF and MIF receptors in EPC recruitment following hypoxia , EPC differentiation and subsequent tube and vessel formation , whereas CXCL12 , a mediator of early EPC recruitment , does not contribute to the remodeling process . By discerning the contributions of key angiogenic chemokines and EPCs , these findings offer valuable mechanistic insight into mouse models of angiogenesis and help to define the intricate interplay between EPC-derived angiogenic cargo factors , EPCs , and the angiogenic target tissue .
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23184390
|
DYT1 is caused by a partly penetrant dominant mutation in TOR1A that leads to a glutamic acid deletion ( \u0394E ) in torsinA . Identifying environmental factors that modulate disease pathogenesis and penetrance could help design therapeutic strategies for dystonia . Several cell-based studies suggest that expression of torsinA(\u0394E) increases the susceptibility of neuronal cells to challenges to their oxidative/energy metabolism . Based on those reports , we hypothesized that mice expressing torsinA(\u0394E) would be more susceptible than control littermates to the effects of oxidative stress and ATP deficits caused by disruption of the mitochondrial respiratory chain in neurons . To test this hypothesis , we administered 20 or 50 mg/kg/day of the irreversible complex-II inhibitor 3-nitropropionic acid ( 3-NP ) intraperitoneally for 15 consecutive days to young heterozygote DYT1 knock-in ( KI ) mice and wild type littermates . Repeated phenotypic assessments were performed at baseline , during and after the injections . Animals were then sacrificed and their brains processed for protein analysis . The administration of 20 mg/kg 3-NP led to increased levels of torsinA in the striatum , the main target of 3-NP , but did not cause motor dysfunction in DYT1 KI or control mice . The administration of 50 mg/kg/day of 3-NP caused the death of of wild type animals . Interestingly , DYT1 KI animals showed significantly reduced mortality . Surviving animals exhibited abnormal motor behavior during and right after the injection period , but recovered by 4 weeks postinjection independent of genotype . In contrast to the findings reported in cultured cells , these studies suggest the DYT1 mutation does not sensitize central neurons against the toxic effects of oxidative stress and energy deficits .
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22880064
|
OBJECTIVE The signalling molecule protein kinase B ( Akt ) modulates many cellular processes . Phosphatidylinositol 3-kinase ( PI3K)/Akt signalling pathways play important roles in tumour angiogenesis . The aim of this study was to determine the role of phosphorylated Akt ( pAkt ) in angiogenesis and its correlation with vascular endothelial growth factor ( VEGF)-A in gastric adenocarcinoma . METHODS Tumour tissue and matched healthy gastric mucosa were obtained from patients undergoing surgical resection of gastric adenocarcinoma . Akt and pAkt were detected via Western blotting . VEGF-A , pAkt and CD34 were examined by immunohistochemistry . RESULTS Akt and pAkt protein levels were significantly higher in gastric cancer tissue than in normal tissue ( n = 48 patients ) . Positive VEGF-A immunostaining was significantly associated with pAkt immunostaining . Microvessel density was correlated with both VEGF-A and pAkt positivity . CONCLUSIONS Phosphorylated Akt and VEGF-A are involved in angiogenesis of gastric adenocarcinoma , and Akt activation may contribute to angiogenesis via VEGF-A upregulation . The PI3K/Akt/VEGF signalling pathway may be involved in gastric adeno carcinoma .
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1,
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23321169
|
Gene therapy vectors based on the adeno-associated virus ( AAV ) are extremely efficient for gene transfer into post-mitotic cells of heart , muscle , brain , and retina . The reason for their exquisite tropism for these cells has long remained elusive . Here , we show that upon terminal differentiation , cardiac and skeletal myocytes downregulate proteins of the DNA damage response ( DDR ) and that this markedly induces permissivity to AAV transduction . We observed that expression of members of the MRN complex ( Mre11 , Rad50 , Nbs1 ) , which bind the incoming AAV genomes , faded in cardiomyocytes at weeks after birth , as well as upon myoblast differentiation in vitro ; in both cases , withdrawal of the cells from the cell cycle coincided with increased AAV permissivity . Treatment of proliferating cells with short-interfering RNAs ( siRNAs ) against the MRN proteins , or with microRNA-24 , which is normally upregulated upon terminal differentiation and negatively controls the Nbs1 levels , significantly increased permissivity to AAV transduction . Consistently , delivery of these small RNAs to the juvenile liver concomitant with AAV markedly improved in vivo hepatocyte transduction . Collectively , these findings support the conclusion that cellular DDR proteins inhibit AAV transduction and that terminal cell differentiation relieves this restriction .
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22850678
|
Carbon nanotubes have a wide range of applications in various industries and their use is likely to rise in the future . Currently , a major concern is that with the increasing use and production of these materials , there may be increased health risks to exposed workers . Long ( > 15 microm ) straight nanotubes may undergo frustrated phagocytosis which is likely to result in reduced clearance . We examine here the effects of multiwalled carbon nanotubes of different sizes on monocytic THP-1 cells , with regard to their ability to stimulate increased expression of the HO-1 and GST genes and their ability to produce nuclear translocation of the transcription factor , Nrf2 , as well as the release of several pro-inflammatory cytokines and mediators of inflammation . Our results suggest that long ( 50 microm ) carbon nanotubes ( 62.5 microg/ml for 4 hours ) produce increased nuclear translocation of Nrf2 and increased HO-1 gene expression compared with shorter entangled nanotubes . There was no increased gene expression for GST . The long nanotubes ( NT1 ) caused increased release of the proinflammatory cytokine IL-1beta , an effect which was diminished by the antioxidant trolox , suggesting a role of oxidative stress in the upregulation of this cytokine . Tentatively , our study suggests that long carbon nanotubes may exert their effect in THP-1 cells in part via an oxidative stress mechanism .
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1
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21179939
|
Metformin is a well-established diabetes drug that prevents the onset of most types of human cancers in diabetic patients , especially by targeting cancer stem cells . Metformin exerts its protective effects by functioning as a weak " mitochondrial poison, " as it acts as a complex I inhibitor and prevents oxidative mitochondrial metabolism ( OXPHOS ) . Thus , mitochondrial metabolism must play an essential role in promoting tumor growth . To determine the functional role of " mitochondrial health " in breast cancer pathogenesis , here we used mitochondrial uncoupling proteins ( UCPs ) to genetically induce mitochondrial dysfunction in either human breast cancer cells ( MDA-MB-231 ) or cancer-associated fibroblasts ( hTERT-BJ1 cells ) . Our results directly show that all three UCP family members ( UCP-1/2/3 ) induce autophagy and mitochondrial dysfunction in human breast cancer cells , which results in significant reductions in tumor growth . Conversely , induction of mitochondrial dysfunction in cancer-associated fibroblasts has just the opposite effect . More specifically , overexpression of UCP-1 in stromal fibroblasts increases β-oxidation , ketone body production and the release of ATP-rich vesicles , which " fuels " tumor growth by providing high-energy nutrients in a paracrine fashion to epithelial cancer cells . Hence , the effects of mitochondrial dysfunction are truly compartment-specific . Thus , we conclude that the beneficial anticancer effects of mitochondrial inhibitors ( such as metformin ) may be attributed to the induction of mitochondrial dysfunction in the epithelial cancer cell compartment . Our studies identify cancer cell mitochondria as a clear target for drug discovery and for novel therapeutic interventions .
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23257779
|
The development of targeted therapies and immunotherapies has markedly advanced the treatment of metastasized melanoma . While treatment with selective BRAF(V600E) inhibitors ( like vemurafenib or dabrafenib ) leads to high response rates but short response duration , CTLA-4 blocking therapies induce sustained responses , but only in a limited number of patients . The combination of these diametric treatment approaches may further improve survival , but pre-clinical data concerning this approach is limited . We investigated , using Tyr::CreER(T2)PTEN(F-/-)BRAF(F-V600E/+) inducible melanoma mice , whether BRAF(V600E) inhibition can synergize with anti-CTLA-4 mAb treatment , focusing on the interaction between the BRAF(V600E) inhibitor PLX4720 and the immune system . While PLX4720 treatment strongly decreased tumor growth , it did not induce cell death in BRAF(V600E)/PTEN(-/-) melanomas . More strikingly , PLX4720 treatment led to a decreased frequency of tumor-resident T cells , NK-cells , MDSCs and macrophages , which could not be restored by the addition of anti-CTLA-4 mAb . As this effect was not observed upon treatment of BRAF wild-type B16F10 tumors , we conclude that the decreased frequency of immune cells correlates to BRAF(V600E) inhibition in tumor cells and is not due to an off-target effect of PLX4720 on immune cells . Furthermore , anti-CTLA-4 mAb treatment of inducible melanoma mice treated with PLX4720 did not result in enhanced tumor control , while anti-CTLA-4 mAb treatment did improve the effect of tumor-vaccination in B16F10-inoculated mice . Our data suggest that vemurafenib may negatively affect the immune activity within the tumor . Therefore , the potential effect of targeted therapy on the tumor-microenvironment should be taken into consideration in the design of clinical trials combining targeted and immunotherapy .
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22934253
|
Advanced or metastatic prostate cancer is treated by androgen deprivation ; however , patients inevitably relapse with castration-resistant prostate cancer ( CRPC ) . CRPC remains dependent on androgen receptor ( AR ) signaling , which may include constitutive , ligand-independent action of naturally occurring AR splice variants . For example , the AR splice variant AR3 ( also termed AR-V7 ) is expressed in CRPC and is linked to poor prognosis . Vav3 , a Rho GTPase guanine nucleotide exchange factor , is an AR coactivator that is up-regulated in human prostate cancer compared with benign tissue and in preclinical models of CRPC . Vav3 confers castration-resistant growth to androgen-dependent human prostate cancer cells . Despite the importance of AR coactivators in promoting CRPC , the potential role of these regulatory proteins in modulating AR splice variant activity is unknown . We examined the contributions of Vav3 to AR activity in two CRPC cell lines that naturally express relatively high levels of Vav3 and AR3 . Vav3 or AR3 knockdown greatly attenuated cell proliferation , soft agar growth , and ligand-independent AR activity . Vav3 potently enhanced the transcriptional activity of AR3 and another clinically relevant AR splice variant , ARv567es . Vav3 knockdown resulted in lowered nuclear AR3 levels , whereas total AR3 levels remained similar . Conversely , overexpression of Vav3 resulted in increased nuclear AR3 . Coimmunoprecipitation revealed that AR3 and Vav3 interact . These novel data demonstrating physical and functional interactions between Vav3 , a unique AR coactivator , and an AR splice variant provide insights into the mechanisms by which Vav3 exploits and enhances AR signaling in the progression to CRPC .
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1,
0
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23023561
|
Glioblastoma is one of the most lethal and common malignant human brain tumors , with aggressive proliferation and highly invasive properties . Honokiol derived from Magnolia officinalis is able to cross the blood-brain barrier ( BBB ) and the blood-cerebrospinal fluid barrier ( BCSFB ) , suggesting a strong possibility that it could be an effective drug for the treatment of brain tumors , including glioblastoma . Thus , we investigated the effects of honokiol on the expression of adhesion molecules in TNF-α-stimulated endothelial cells , and cancer growth and invasion were determined in T98G human glioblastoma cells . Honokiol dose-dependently inhibited the expression of intercellular adhesion molecule-1 ( ICAM-1 ) and vascular cell adhesion molecule-1 ( VCAM-1 ) in human umbilical vein endothelial cells ( HUVECs ) stimulated with TNF-α for 6 h . Pretreatment with honokiol significantly reduced the adhesion of T98G cells to HUVECs . Moreover , honokiol inhibited the invasion of T98G cells , suggesting that honokiol has an anti-metastatic effect . In addition , honokiol increased the cytotoxicity of T98G cells in a dose- and time-dependent manner as assayed by MTT . TUNEL assay showed that honokiol significantly induced apoptosis in T98G cells at doses of 10 �M or more . The induction of apoptotic cell death was mediated by the downregulation of the anti-apoptotic protein Bcl-2 and the upregulation of the pro-apoptotic protein Bax . Taken together , the results of this study suggest that honokiol exerts an anticancer effect by preventing metastasis and inducing apoptotic cell death of brain tumor cells .
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22895699
|
BACKGROUND Adult human mesenchymal stem cells ( hMSC ) have been shown to home to sites of carcinoma and affect biological processes , including tumour growth and metastasis . Previous findings have been conflicting and a clear understanding of the effects of hMSCs on cancer remains to be established . Therefore , we set out to investigate the impact of hMSCs on the oestrogen receptor positive , hormone-dependent breast carcinoma cell line MCF-7 . RESULTS In this study , we show the effects of hMSCs on cancer cells are mediated through a secreted factor(s) which are enhanced by cancer cell-hMSC contact/communication . In addition to enhanced proliferation when in co-culture with hMSCs , MCF-7 cells were found to have increased migration potential in vitro . Inhibition of ER signalling by the pure anti-oestrogen ICI 182,780 decreased the effect of hMSCs on MCF-7 cell proliferation and migration supporting a role for ER signalling in the hMSC/MCF-7 cell interaction . Additionally , hMSCs have been shown to secrete a wide variety of growth factors and chemokines including stromal cell-derived factor-1 ( SDF-1 ) . This coupled with the knowledge that SDF-1 is an ER-mediated gene linked with hormone-independence and metastasis led to the investigation of the SDF-1/CXCR4 signalling axis in hMSC-MCF-7 cell interaction . Experiments revealed an increase in SDF-1 gene expression both in vivo and in vitro when MCF-7 cells were cultured with hMSCs . SDF-1 treatment of MCF-7 cells alone increased proliferation to just below that seen with hMSC co-culture . Additionally , blocking SDF-1 signalling using a CXCR4-specific inhibitor decreased hMSC induced proliferation and migration of MCF-7 . However , the combined treatment of ICI and AMD3100 reduced MCF-7 cell proliferation and migration below control levels , indicating targeting both the ER and CXCR4 pathways is effective in decreasing the hMSCs induction of MCF-7 cell proliferation and migration . CONCLUSIONS The sum of these data reveals the relationship between tumour microenvironment and tumour growth and progression . Better understanding of the mechanisms involved in this tumour stroma cell interaction may provide novel targets for the development of treatment strategies for oestrogen receptor positive , hormone-independent , and endocrine-resistant breast carcinoma .
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1,
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21087507
|
Human breast tumors are infiltrated by memory CD4(+) T cells along with increased numbers of regulatory T cells ( Treg ) and plasmacytoid dendritic cells ( pDC ) that facilitate immune escape and correlate with poor prognosis . Here , we report that inducible costimulatory molecule ( ICOS ) , a T cell costimulatory molecule of the CTLA4/PD1/CD28 family , is expressed mostly by tumor-associated Treg in primary breast tumors . A large proportion of these ICOS(+) Treg were Ki67(+) and this evident proliferative expansion was found to rely on interactions with tumor-associated pDC . Indeed , tumor-associated Treg highly expanded in presence of pDC but failed to proliferate under CD3/CD28 signal . In vitro experiments revealed that the addition of a neutralizing anti-ICOS antibody blocked pDC-induced Treg expansion and interleukin-10 secretion by memory CD4(+) T cells , establishing a pivotal role for ICOS in this process . Supporting these findings , the presence of ICOS(+) cells in clinical specimens of breast cancer correlated with a poor prognosis . Together , our results highlight an important relationship between Treg and pDC in breast tumors , and show that ICOS/ICOS-L interaction is a central event in immunosuppression of tumor-associated memory CD4(+) T cells . These findings strongly rationalize antibody-mediated ICOS blockade as a powerful clinical strategy to correct immune escape and promote therapeutic responses in breast cancer . Cancer Res ; 72(23) ; 6130-41. �2012 AACR .
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23026134
|
Cytokine-dependent cell lines have been used to analyze the cytokine-induced cellular signaling and the mechanism of oncogenesis . In the current study , we analyzed MOTN-1 and PLT-2 cell lines established from different stages of a T-cell large granular lymphocyte leukemia patient ( Daibata et al. 2004 ) . MOTN-1 is IL-2-dependent derived from the chronic phase , whereas IL-2-independent PLT-2 is from the aggressive and terminal stage . They shared considerable chromosome abnormalities and the pattern of T-cell receptor rearrangement , presuming that the cytokine independence of PLT-2 was due to the additive genetic abnormality . Besides IL-2 , IL-15 supported MOTN-1 cell growth , because these receptors share beta- and gamma-subunits . IL-2 activated ERK , AKT and STAT pathway of MOTN-1 . STAT3 pathway of PLT-2 was also activated by IL-2 , suggesting intact IL-2 induces signal transduction of PLT-2 . However , ERK1/2 but not AKT , was continuously activated in PLT-2 , consistent with the increased Ras-activity of PLT-2 . Sequence analysis revealed KRAS G12A mutation but not NRAS and HRAS mutation of PLT-2 but not MOTN-1 . Another signaling molecule affecting Ras-signaling pathway , SHP2 , which has been frequently mutated in juvenile myelomonocytic leukemia ( JMML ) , did not show mutation . Moreover , MEK inhibitor , PD98059 , as well as farnesylation inhibitor inhibited PLT-2 cell growth . Using NIH3T3 and MOTN-1 , ERK activation , increased cell proliferation and survival by KRAS G12A were shown , suggesting the important role of KRAS G12A in IL-2-independent growth of PLT-2 . Taken together , KRAS G12A is important for IL-2-independent growth of PLT-2 cells and suggests the possibility of involvement of KRAS mutation with disease progression .
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23092099
|
Nasopharyngeal carcinoma ( NPC ) is an endemic malignant disease of the head and neck region with unique features including striking ethnic and geographic variations as well as multifactorial etiology . Previous studies have demonstrated the anticancer properties of genistein , the major soy isoflavonoid , in several human cancer cells such as breast , prostate , colon , gastric , lung , and hepatoma . However , the action of genistein in NPC cells has not been determined . In this study , we investigated the inhibitory effects of genistein on NPC cells and its possible underlying mechanisms . We found that genistein dose-dependently inhibited the proliferation of human NPC cell line CNE2 cells . DNA flow cytometric analysis revealed that 30 to 120 microM genistein induced dramatic G2/M phase arrest in NPC cells . The mRNA expression levels , as shown by gene expression array and quantitative real-time polymerase chain reaction , and the protein expression levels of the cell cycle regulators p21(Cip1) and ATR ( Ataxia telangiectasia and Rad3 related ) were elevated following genistein treatment . Interestingly , we also observed concomitant induction of p15(Ink4b) in genistein induced inhibitory effects in NPC cells . Moreover , selective estrogen receptor modulators did not affect genistein induced growth inhibition . These findings provide new insights into the potential intervention of NPC with genistein .
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20574925
|
BACKGROUND : Although quiescence ( reversible cell cycle arrest ) is a key part in the life history and fate of many mammalian cell types , the mechanisms of gene regulation in quiescent cells are poorly understood . We sought to clarify the role of microRNAs as regulators of the cellular functions of quiescent human fibroblasts . RESULTS : Using microarrays , we discovered that the expression of the majority of profiled microRNAs differed between proliferating and quiescent fibroblasts . Fibroblasts induced into quiescence by contact inhibition or serum starvation had similar microRNA profiles , indicating common changes induced by distinct quiescence signals . By analyzing the gene expression patterns of microRNA target genes with quiescence , we discovered a strong regulatory function for miR-29 , which is downregulated with quiescence . Using microarrays and immunoblotting , we confirmed that miR-29 targets genes encoding collagen and other extracellular matrix proteins and that those target genes are induced in quiescence . In addition , overexpression of miR-29 resulted in more rapid cell cycle re-entry from quiescence . We also found that let-7 and miR-125 were upregulated in quiescent cells . Overexpression of either one alone resulted in slower cell cycle re-entry from quiescence , while the combination of both together slowed cell cycle re-entry even further . CONCLUSIONS : microRNAs regulate key aspects of fibroblast quiescence including the proliferative state of the cells as well as their gene expression profiles , in particular , the induction of extracellular matrix proteins in quiescent fibroblasts .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
23259597
|
Luteolin is a plant flavonoid which exhibits anti-oxidative , anti-inflammatory and anti-tumor effects . However , the antiproliferative potential of luteolin is not fully understood . In this study , we investigated the effect of luteolin on cell cycling and apoptosis in human esophageal squamous carcinoma cell line Eca109 cells . MTT assays showed that luteolin had obvious cytotoxicity on Eca109 with an IC50 of 70.7�1.72 μM at 24 h . Luteolin arrested cell cycle progression in the G0/G1 phase and prevented entry into S phase in a dose- and time-dependent manner. as assessed by FCM . Luteolin induced apoptosis of Eca109 cells was demonstrated by AO/EB staining assay and annexin V-FITC/PI staining . Moreover , luteolin downregulated the expression of cyclin D1 , survivin and c-myc , and it also upregulated the expression of p53 , in line with the fact that luteolin was able to inhibit Eca109 cell proliferation .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
23317200
|
BACKGROUND As a highly conserved system , the activation of the Notch pathway has been implicated in the tumorigenesis of various hematologic diseases , including leukemias , lymphomas , and multiple myeloma . The Notch3 receptor is frequently expressed in T-cell acute lymphoblastic leukemia ( T-ALL ) . METHODS To explore its possibility as a therapeutic target for T-ALL , we investigated the effect of Notch3 silencing on Jurkat and SupT1 cells using a novel tumor-specific short hairpin RNA ( shRNA ) driven by survivin promoters . RESULTS We found that downregulated expression of Notch3 correlated with significant apoptosis and inhibition of proliferation . CONCLUSION These facts suggest that downregulating expression of Notch3 could attenuate the Notch signaling activity in T-ALL . All these results indicate that inhibition of Notch3 expression can result in potent antitumor activity in T-ALL .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
21940234
|
PURPOSE Osteosarcoma is an aggressive primary bone cancer characterized by expression of platelet-derived growth factor ( PDGF ) and its cognate receptor . Coexpression of the growth factor and receptor suggests their role in autocrine or paracrine growth mechanisms . It has been reported previously that STI571 has specific activity in inhibiting select tyrosine kinase receptors , including PDGF and c-Kit . Osteosarcomas express low levels of c-Kit but abundant levels of PDGF receptor ( PDGFR ) . EXPERIMENTAL DESIGN To investigate the potential of STI571 as therapy for osteosarcoma , we studied its effects on PDGF-mediated cell growth in vitro and in an in vivo mouse model . RESULTS PDGF acted as a potent mitogen in a dose-dependent manner in two osteosarcoma cell lines . STI571 ( 1.0 micro M ) inhibited both PDGFR-alpha and PDGFR-beta phosphorylation and the downstream phosphorylation targets extracellular signal-regulated kinase and Akt . STI571 also inhibited PDGF-mediated growth and induced apoptosis in vitro as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and terminal deoxynucleotidyl transferase-mediated nick end labeling staining . To study the effect of STI571 alone or in combination with Taxol in an in vivo model , an osteosarcoma cell line ( KRIB ) was transplanted into the tibia of athymic nude mice . Mice were treated with STI571 ( 50 mg/kg p.o. q M-F ) , Taxol ( 8 mg/kg i.p. weekly ) , or STI571 plus Taxol for 6 weeks . There was no significant difference in tumor size between treatment and control mice . Aberrant signaling pathways downstream of the PDGFR in the v-Ki-ras oncogene-transformed KRIB cell line may in part explain this finding . CONCLUSIONS Our data demonstrate that STI571 inhibits PDGF-mediated growth and leads to apoptosis of osteosarcoma cells in vitro by selective inhibition of the PDGFR tyrosine kinase . The effectiveness of STI571 in our studies suggests targeting of PDGFRs as a novel treatment for osteosarcoma .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
12429650
|
BACKGROUND Autotaxin ( ATX ) is an extracellular lysophospholipase D that generates lysophosphatidic acid ( LPA ) from lysophosphatidylcholine ( LPC ) . Both ATX and LPA have been shown to be involved in many cancers . However , the functional role of ATX and the regulation of ATX expression in human hepatocellular carcinoma ( HCC ) remain elusive . RESULTS In this study , ATX expression was evaluated in tissues from 38 human HCC and 10 normal control subjects . ATX was detected mainly in tumor cells within tissue sections and its over-expression in HCC was specifically correlated with inflammation and liver cirrhosis . In addition , ATX expression was examined in normal human hepatocytes and liver cancer cell lines . Hepatoma Hep3B and Huh7 cells displayed stronger ATX expression than hepatoblastoma HepG2 cells and normal hepatocytes did . Proinflammtory cytokine tumor necrosis factor alpha ( TNF-alpha ) promoted ATX expression and secretion selectively in Hep3B and Huh7 cells , which led to a corresponding increase in lysophospholipase-D activity . Moreover , we explored the mechanism governing the expression of ATX in hepatoma cells and established a critical role of nuclear factor-kappa B ( NF-kappaB ) in basal and TNF-alpha induced ATX expression . Further study showed that secreted enzymatically active ATX stimulated Hep3B cell invasion . CONCLUSIONS This report highlights for the first time the clinical and biological evidence for the involvement of ATX in human HCC . Our observation that links the TNF-alpha/NF-kappaB axis and the ATX-LPA signaling pathway suggests that ATX is likely playing an important role in inflammation related liver tumorigenesis .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
20356387
|
Histone H3 methylation at lysine 4 ( K4 ) is associated with euchromatic regions and is thought to be important for the transcriptional activation of genes during differentiation . In this study , we found that di- and tri-methylation of histone H3 at K4 and acetylation of histones H3 and H4 from the promoter/enhancer to the transcribed region close to the transcription initiation site of the solute carrier family 2 , member 5 ( SLC2A5 ) gene , and its expression , were induced by differentiation of intestine-like Caco-2 cells . These effects were accompanied by contact inhibition of cell growth of these cells . Furthermore , these modifications were induced by co-treatment with a synthetic glucocorticoid hormone dexamethasone and a p44/42 mitogen-activated protein kinase inhibitor PD89059 . Our results suggest that methylation of histone H3 at K4 and acetylation of histones H3 and H4 are involved in SLC2A5 gene induction associated with intestinal differentiation of Caco-2 cells .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
20043883
|
Stannous chloride ( SnCl(2) ) and UVA induce DNA lesions through ROS . The aim of this work was to study the toxicity induced by UVA preillumination , followed by SnCl(2) treatment . E. coli BER mutants were used to identify genes which could play a role in DNA lesion repair generated by these agents . The survival assays showed ( i ) The nfo mutant was the most sensitive to SnCl(2) ; ( ii ) lethal synergistic effect was observed after UVA pre-illumination , plus SnCl(2) incubation , the nfo mutant being the most sensitive ; ( iii ) wild type and nfo mutants , transformed with pBW21 plasmid ( nfo(+) ) had their survival increased following treatments . The alkaline agarose gel electrophoresis assays pointed that ( i ) UVA induced DNA breaks and fpg mutant was the most sensitive ; ( ii ) SnCl(2)-induced DNA strand breaks were higher than those from UVA and nfo mutant had the slowest repair kinetics ; ( iii ) UVA + SnCl(2) promoted an increase in DNA breaks than SnCl(2) and , again , nfo mutant displayed the slowest repair kinetics . In summary , Nfo protects E. coli cells against damage induced by SnCl(2) and UVA + SnCl(2) .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20300433
|
PURPOSE This study aims to investigate the role of the aberrant expression of Transkelolase-like 1 ( TKTL1 ) in head and neck squamous cell carcinoma ( HNSCC ) tumorigenesis and to characterize TKTL1 contribution to HNSCC tumorigenesis through aerobic glycolysis and HIF1alpha stabilization . EXPERIMENTAL DESIGN TKTL1 promoter hypomethylation and mRNA/protein aberrant expression were studied in human HNSCC tumor samples and normal mucosas . Oncogenic functions of TKTL1 were examined in HNSCC cell line panels and tumor xenograft models with TKTL1 expression construct . The metabolite levels of fructose-6-phosphate , glyceraldehydes-3-phosphate , pyruvate , lactate , and the levels of HIF1alpha protein and its downsteam glycolytic targets were compared between the TKTL1-expressing and vehicle-expressing HNSCC cells . Meanwhile , the effects of HIF1alpha/glycolytic inhibitors were evaluated on the TKTL1 transfectants . RESULTS TKTL1 exhibits high frequency of promoter hypomethylation in HNSCC tumors compared with the normal mucosas , correlating with its overexpression in HNSCC . Overexpression of TKTL1 in HNSCC cells promoted cellular proliferation and enhanced tumor growth in vitro and in vivo . Overexpression of TKTL1 increased the production of fructose-6-phosphate and glyceraldehyde-3-phosphate , in turn elevating the production of pyruvate and lactate , resulting in the normoxic stabilization of the malignancy-promoting transcription factor HIF1alpha and the upregulation of downstream glycolytic enzymes . Notably , the reduction of TKTL1 expression decreased HIF1alpha accumulation and inhibition with HIF1alpha and/or the glycolysis inhibitor could abrogate the growth effects mediated by TKTL1 overexpression . CONCLUSION TKTL1 is a novel candidate oncogene that is epigenetically activated by aberrant hypomethlation and contributes to a malignant phenotype through altered glycolytic metabolism and HIF1alpha accumulation .
|
[
0,
0,
1,
0,
0,
0,
0,
0,
0,
0
] |
20103683
|
The progression of prostate cancers ( PCs ) to locally invasive , androgen-independent and metastatic disease states is generally associated with treatment resistance and disease relapse . The present study was undertaken to establish the possibility of using a combination of specific oncogenic products , including epidermal growth factor receptor ( EGFR ) , pAkt , nuclear factor-kappaB ( NF-κB ) and macrophage inhibitory cytokine-1 ( MIC-1 ) as biomarkers and therapeutic targets for optimizing the management of patients with localized PC at earlier disease stages . The immunohistochemical and immunofluorescence data have revealed that the expression levels of EGFR , Ser(473)-pAkt , NF-κB p65 and MIC-1 proteins were significantly enhanced in the same subset of 76 cases of prostatic adenocarcinoma specimens during the disease progression and these biomarkers were expressed in a small subpopulation of CD133(+) PC cells and the bulk tumor mass of CD133(-) PC cells . Importantly , all of these biomarkers were also overexpressed in 80-100% of 30 PC metastasis bone tissue specimens . Moreover , the results have indicated that the EGF-EGFR signaling pathway can provide critical functions for the self-renewal of side population ( SP ) cells endowed with stem cell-like features from highly invasive WPE1-NB26 cells . Of therapeutic interest , the targeting of EGFR , pAkt , NF-κB or MIC-1 was also effective at suppressing the basal and EGF-promoted prostasphere formation by SP WPE1-NB26 cells , inducing disintegration of SP cell-derived prostaspheres and decreasing the viability of SP and non-SP WPE1-NB26 cell fractions . Also , the targeting of these oncogenic products induced the caspase-dependent apoptosis in chemoresistant SP WPE1-NB26 cells and enhanced their sensibility to the cytotoxic effects induced by docetaxel . These findings suggest that the combined use of EGFR , pAkt , NF-κB and/or MIC-1 may represent promising strategies for improving the accuracy of current diagnostic and prognostic methods and efficacy of treatments of PC patients in considering the disease heterogeneity , thereby preventing PC progression to metastatic and lethal disease states .
|
[
1,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22384099
|
Melittin ( 1 ) is a major polypeptide in honey bee venom that has been used traditionally against chronic inflammation and cancer . However , its molecular mechanism has not been determined . In this study , the antitumor effect of 1 was compared with that of NS398 , a cyclooxygenase-2 ( COX-2 ) inhibitor , in vivo and in vitro . Subcutaneous injection of 1 at 0.5 and 5 mg/kg suppressed significantly vascular endothelial growth factor ( VEGF)-A-transfected highly metastatic Lewis lung cancer ( VEGF-A-hm LLC ) tumor growth by 25% and 57% , respectively . Also , 1 inhibited significantly the number of vessels around VEGF-A-hm LLC cells . The results were superior to those obtained in the mice treated with NS398 . Compound 1 dose-dependently inhibited proliferation and tube formation in human umbilical vein endothelial cells ( VEGF-A-HUVECs ) , without affecting cell viability in native HUVECs . In addition , 1 decreased the expression of VEGF receptor-2 ( VEGFR-2 ) , COX-2 , and prostaglandin E(2) ( PGE(2) ) in VEGF-A-transfected HUVECs . These effects were accompanied by a reduction of the phosphorylation of extracellular signal-regulated kinase 1/2 and c-jun N-terminal kinase , whereas it increased the phosphorylation of p38 mitogen-activated protein kinase ( MAPK ) . SB203580 abolished the downregulation of COX-2 and VEGFR-2 and the inhibition of cell proliferation by 1 . The antitumor activity of 1 may be associated with antiangiogenic actions via inhibiting VEGFR-2 and inflammatory mediators involved in the MAPK signaling pathway .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
1,
0
] |
23110475
|
In patients with advanced bladder cancer , glucocorticoids are frequently given to reduce acute toxicity , particularly hyperemesis , during chemotherapy , as well as to improve cachectic conditions . However , it remains unclear whether glucocorticoids directly affect the development and progression of bladder cancer through the glucocorticoid receptor pathway . Glucocorticoid receptor expression was first investigated in human bladder cancer lines and tissue microarrays . Then , the effects of dexamethasone on glucocorticoid receptor transcription , cell proliferation , apoptosis/cell cycle , and invasion were examined in bladder cancer lines . Finally , mouse xenograft models for bladder cancer were used to assess the efficacy of dexamethasone on tumor progression . All the cell lines and tissues examined were found to express glucocorticoid receptor . Dexamethasone increased glucocorticoid receptor-mediated reporter activity and cell proliferation , and inhibited apoptosis in the presence or absence of cisplatin . In contrast , dexamethasone suppressed cell invasion , the expression of its related genes [ MMP-2/MMP-9 , interleukin ( IL)-6 , VEGF ] , and the activity of MMP-2/MMP-9 , and also induced mesenchymal-to-epithelial transition . In addition , dexamethasone increased IκBα protein levels and cytosolic accumulation of NF-κB . In xenograft-bearing mice , dexamethasone slightly augmented the growth of the inoculated tumors but completely prevented the development of bloody ascites , suggestive of peritoneal dissemination of tumor cells , and actual metastasis . In all these assays , dexamethasone effects were abolished by a glucocorticoid receptor antagonist or glucocorticoid receptor knockdown via RNA interference . Thus , glucocorticoid receptor activation resulted in promotion of cell proliferation via inhibiting apoptosis yet repression of cell invasion and metastasis . These results may provide a basis of developing improved chemotherapy regimens , including or excluding glucocorticoid receptor agonists/antagonists , for urothelial carcinoma .
|
[
1,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
23033490
|
The aim of this work was to characterize the antitumoral activity of the plant compound 7-epi-nemorosone in prostate carcinoma cell lines . Prostate cancer is the most frequently diagnosed malignancy and the second-leading cause of cancer death in men . In spite of the current therapeutic options for this cancer entity , many patients die due to metastases in distant organs and acquired chemotherapy resistance . Thus , approaches to provide improvements in outcome and quality of life for such patients are urgently needed . Recently , the polyisoprenylated benzophenone 7-epi-nemorosone , originally collected by honeybees from Clusia rosea and Clusia grandiflora ( Clusiaceae ) , has been described to be a potent antitumoral agent . Here , its activity in prostate carcinoma is reported. 7-epi-nemorosone was isolated from Caribbean propolis employing RP-HPLC techniques . Its cytotoxicity was assessed using the MTT proliferation assay in human androgen-dependent prostate carcinoma LNCaP cells including an MDR1(+) sub-line . No cross-resistance was detected . FACS-based cell cycle analysis revealed a significant increase in the sub-G0/G1 , G1 , and depletion in the S phase populations . A concomitant down-regulation of cyclins D1/D3 and CDK 4/6 in LNCaP cells was detected by Western blot . Annexin-V-FITC labeling and caspase-3 cleavage assays showed that 7-epi-nemorosone induced apoptotic events . Major signal transduction elements such as p38 MAPK and Akt/PKB as well as androgen receptor AR and PSA production were found to be down-regulated after exposure to the drug . ERK1/2 protein levels and phosphorylation status were down-regulated accompanied by up-regulation but inhibition of the activity of their immediate upstream kinases MEK1/2 . Additionally , Akt/PKB enzymatic activity was effectively inhibited at a similar concentration as for MEK1/2 . Here , we demonstrate for the first time that 7-epi-nemorosone exerts cytotoxicity in an androgen-dependent prostate carcinoma entity by targeting the MEK1/2 signal transducer .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22981203
|
Although tumor-associated macrophages ( TAMs ) are involved in tumor growth and metastasis , the mechanisms controlling their pro-tumoral activities remain largely unknown . The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors . In this study , we exploited the predominant expression of LysM in myeloid cells to generate c-Myc(fl/fl) LysM(cre/+) mice , which lack c-Myc in macrophages , to investigate the role of macrophage c-MYC expression in cancer . Under steady-state conditions , immune system parameters in c-Myc(fl/fl) LysM(cre/+) mice appeared normal , including the abundance of different subsets of bone marrow hematopoietic stem cells , precursors and circulating cells , macrophage density , and immune organ structure . In a model of melanoma , however , TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions ( e.g. , reduced expression of VEGF , MMP9 , and HIF1α ) that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Myc(fl/fl) LysM(cre/+) mice . Macrophage c-Myc deletion also diminished fibrosarcoma growth . These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy .
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[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23028984
|
OBJECTIVE To explore the clinical significance of miRNA-216a expression in pancreatic cancer . METHODS Fourteen patients with pancreatic cancer undergoing pancreaticoduodenectomy and 6 patients with benign pancreas lesions were examined for miR-216a expressions in the tumor or lesion tissues using Agilent Human miRNA Microarray ( V12.0 ) . The relationship between miR-216a expressions and the clinicopathological features of the patients was analyzed . RESULTS The expression of miRNA-216a was significantly lower in pancreatic cancer than in benign pancreas lesions ( P=0.000 ) . The expression of miRNA-216a was significantly correlated with the T stage of the tumor ( P=0.002 ) , but not with the patients ' age , gender , smoking status , tumor stage , lymph node metastases , distant metastasis , tumor differentiation , nerve invasion , vessel invasion or serum CA19-9 level ( P>0.05 ) . CONCLUSIONS The down-regulated expression of miR-216a in pancreatic cancer suggests the involvement of miR-216a in the tumorigenesis and development of pancreatic cancer. miR-216a may potentially serve as a novel tumor marker and also a prognostic factor for pancreatic cancer .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23174591
|
The flow of interstitial fluid and the associated interstitial fluid pressure ( IFP ) in solid tumors and surrounding host tissues have been identified as critical elements in cancer growth and vascularization . Both experimental and theoretical studies have shown that tumors may present elevated IFP , which can be a formidable physical barrier for delivery of cell nutrients and small molecules into the tumor . Elevated IFP may also exacerbate gradients of biochemical signals such as angiogenic factors released by tumors into the surrounding tissues . These studies have helped to understand both biochemical signaling and treatment prognosis . Building upon previous work , here we develop a vascular tumor growth model by coupling a continuous growth model with a discrete angiogenesis model . We include fluid/oxygen extravasation as well as a continuous lymphatic field , and study the micro-environmental fluid dynamics and their effect on tumor growth by accounting for blood flow , transcapillary fluid flux , interstitial fluid flow , and lymphatic drainage . We thus elucidate further the non-trivial relationship between the key elements contributing to the effects of interstitial pressure in solid tumors . In particular , we study the effect of IFP on oxygen extravasation and show that small blood/lymphatic vessel resistance and collapse may contribute to lower transcapillary fluid/oxygen flux , thus decreasing the rate of tumor growth . We also investigate the effect of tumor vascular pathologies , including elevated vascular and interstitial hydraulic conductivities inside the tumor as well as diminished osmotic pressure differences , on the fluid flow across the tumor capillary bed , the lymphatic drainage , and the IFP . Our results reveal that elevated interstitial hydraulic conductivity together with poor lymphatic function is the root cause of the development of plateau profiles of the IFP in the tumor , which have been observed in experiments , and contributes to a more uniform distribution of oxygen , solid tumor pressure and a broad-based collapse of the tumor lymphatics . We also find that the rate that IFF is fluxed into the lymphatics and host tissue is largely controlled by an elevated vascular hydraulic conductivity in the tumor . We discuss the implications of these results on microenvironmental transport barriers , and the tumor invasive and metastatic potential . Our results suggest the possibility of developing strategies of targeting tumor cells based on the cues in the interstitial fluid .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23220211
|
BACKGROUND Tissue factor ( TF ) , an initiator of blood coagulation , participates in cancer progression and metastasis . We recently found that inhibition of MAPK/ERK upregulated both full length TF ( flTF ) and soluble isoform TF ( asTF ) gene expression and cell-associated TF activity in breast cancer MDA-MB-231 cells . We explored the possible mechanisms , especially the possible interaction with EGFR and PI3K/Akt pathways . METHODS A plasmid containing TF promoter -2174 plus luciferase reporter gene was introduced into MDA-MB-231 cells to evaluate TF promoter activity . In order to study the interaction of these pathways , ERK inhibitor ( PD98059 ) , PI3K inhibitors ( LY294002 , wortmannin ) , Akt inhibitor ( A6730 ) , and EGFR inhibitor ( erlotinib ) as well as the corresponding siRNAs were used to treat MDA-MB-231 cells , and ovarian cancer OVCAR-3 and SKOV-3 cells . Quantitative PCR and western blot were used to determine TF expression . One stage clotting assays were used to measure pro-coagulation activity of the MDA-MB-231 cells . RESULTS We show that PI3K inhibitors LY294002 , wortmannin and A6730 significantly inhibited TF promoter activity , and reduced TF mRNA and protein levels due to the inhibition of Akt phosphorylation . In contrast , ERK inhibitor PD98059 and ERK siRNA enhanced TF promoter activity by 2.5 fold and induced an increase in TF mRNA and protein levels in a dose dependent manner in these cells . The PI3K/Akt pathway was shown to be involved in PD98059-induced TF expression because the induction was inhibited by PI3K/Akt inhibitors . Most interestingly , the EGFR inhibitor erlotinib and EGFR siRNA also significantly suppressed PD98059- or ERK siRNA-induced TF promoter activity and TF protein expression . Similar results were found with ovarian cancer cells SKOV-3 and OVCAR-3 . Furthermore , in MDA-MB-231 , mRNA levels of asTF were regulated in a similar way to that of TF in response to the cell treatment . CONCLUSIONS This study showed a regulatory mechanism in which MAPK/ERK signals inhibit EGFR/PI3K/Akt-mediated TF expression in breast cancer MDA-MB-231 cells . The same regulation was observed in ovarian cancer OVCAR-3 and SKOV-3 cells . Interestingly , we observed that both flTF and asTF could be regulated in a parallel manner in MDA-MB-231 . As the PI3K/Akt pathway and EGFR regulate TF expression in cancer cells , targeting these signaling components is expected to potentially inhibit TF expression-associated tumor progression .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
22534171
|
Vitexicarpin ( 3 ' , 5-dihydroxy-3 , 4 ' , 6 , 7-tetramethoxyflavone ) , a polymethoxyflavone isolated from Viticis Fructus ( Vitex rotundifolia Linne fil. ) , has long been used as an anti-inflammatory herb in traditional Chinese medicine . It has also been reported that vitexicarpin can inhibit the growth of various cancer cells . However , there is no report elucidating its effect on human prostate carcinoma cells . The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved . MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an IC50 μM . Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death . The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide ( PI)/Annexin V-FITC double staining and flow cytometry . The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase . Furthermore , our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax , and downregulation of antiapoptotic protein Bcl-2 , release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential . Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23464460
|
Each year , more than 700,000 people undergo cancer surgery in the United States . However , more than 40% of those patients develop recurrences and have a poor outcome . Traditionally , the medical community has assumed that recurrent tumors arise from selected tumor clones that are refractory to therapy . However , we found that tumor cells have few phenotypical differences after surgery . Thus , we propose an alternative explanation for the resistance of recurrent tumors . Surgery promotes inhibitory factors that allow lingering immunosuppressive cells to repopulate small pockets of residual disease quickly . Recurrent tumors and draining lymph nodes are infiltrated with M2 ( CD11b(+)F4/80(hi)CD206(hi) and CD11b(+)F4/80(hi)CD124(hi) ) macrophages and CD4(+)Foxp3(+) regulatory T cells . This complex network of immunosuppression in the surrounding tumor microenvironment explains the resistance of tumor recurrences to conventional cancer vaccines despite small tumor size , an intact antitumor immune response , and unaltered cancer cells . Therapeutic strategies coupling antitumor agents with inhibition of immunosuppressive cells potentially could impact the outcomes of more than 250,000 people each year .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23271806
|
Gliomas are aggressive and almost incurable glial brain tumors which frequently display abnormal platelet-derived growth factor ( PDGF ) signaling . Evidence gained from studies on several in vivo animal models has firmly established a causal connection between aberrant PDGF signaling and the formation of some gliomas . However , only recently has significant knowledge been gained regarding crucial issues such as the glioma cell of origin and the relationship between the transforming stimulus and the cellular characteristics of the resulting tumor . Based on recent evidence , we propose that PDGF can bias cell-fate decisions , driving the acquisition of cell type-specific features by the progeny of multipotent neural progenitors , thus determining the shape and direction of the transformation path . Furthermore , recent data about the cellular mechanisms of PDGF-driven glioma progression and maintenance indicate that PDGF may be required , unexpectedly , to override cell contact inhibition and promote glioma cell infiltration rather than to stimulate cell proliferation .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
19832839
|
Onconase ( Onc ) is an amphibian ribonuclease of the pancreatic RNase family that is cytostatic and cytotoxic to several tumor lines . It also shows anti-tumor activity in mouse tumor models and is currently in phase III clinical trials . In animal tests and clinical trials Onc shows lesser toxicity and fewer side effects compared to most chemotherapeutic drugs . Intriguingly , repeated infusions of this protein do not cause apparent immunological reactions in patients . The aim of the present study was to investigate sensitivity to Onc of human lymphocytes during their mitogenic stimulation in response to the polyvalent mitogen phytohemagglutinin ( PHA ) , and in mixed allogeneic lymphocyte cultures . Unexpectedly , we observed that frequency of cells undergoing activation-induced apoptosis was markedly increased in all cultures containing Onc . Apoptosis was measured by flow cytometry using markers that detect activation of caspases , the in situ presence of DNA strand breaks , and loss of fragmented DNA ( 'sub-G1 ' cell subpopulation ) . The enhancement of frequency of activation-induced apoptosis ( up to 244% ) was observed at 4.2-83 nM Onc concentration , which is at least an order magnitude lower than its minimal concentration reported to affect proliferation or induce apoptosis of leukemic and solid tumor cell lines . The cell cycle progression of lymphocytes that responded to PHA mitogenically was not affected at 8.3 or 83 nM Onc concentration . Because activation-induced apoptosis is the key mechanism regulating several in vivo immunological functions including induction of tolerance , the observed effects of Onc may explain the apparent lack of immune reactions to this protein in treated patients . The propensity of Onc to potentiate the activation-induced apoptosis suggests that this drug may have clinical utility as immunomodulating agent , e.g. , to suppress transplant rejection or treat autoimmune diseases .
|
[
0,
1,
0,
0,
0,
0,
0,
1,
0,
0
] |
12429974
|
The thyroid hormone ( T3 ) blocks proliferation and induces differentiation of neuroblastoma N2a-beta cells that overexpress the beta 1 isoform of the T3 receptor . An element in the region responsible for premature termination of transcription mediates a rapid repression of c-myc gene expression by T3 . The hormone also causes a decrease of cyclin D1 gene transcription , and is able to antagonize the activation of the cyclin D1 promoter by Ras . In addition , a strong and sustained increase of the levels of the cyclin kinase inhibitor ( CKI ) p27(Kip1) are found in T3-treated cells . The increased levels of p27(Kip1) lead to a marked inhibition of the kinase activity of the cyclin-CDK2 complexes . As a consequence of these changes , retinoblastoma proteins are hypophosphorylated in T3-treated N2a-beta cells , and progression through the restriction point in the cell cycle is blocked .
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[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
12505306
|
We have used a combination of vitamin A ( all-trans-retinyl palmitate ) , 5-fluorouracil ( 5-FU ) and radiation to treat human head and neck squamous cell carcinoma ( HNSCC ) . This chemoradiotherapy is called " FAR therapy. " In this study we examined the effects of all-trans-retinoic acid ( ATRA ) , the active metabolite of vitamin A , and ATRA plus 5-FU on two HNSCC cell lines ( YCU-N861 and YCU-H891 ) to gain insight into the molecular mechanisms of FAR therapy . ATRA at 1 mM ( the order of concentration found in HNSCC tumors treated with FAR therapy ) inhibited cell proliferation and caused G1 cell cycle arrest in both cell lines . This was associated with a decrease in cyclin D1 , an increase in p27(Kip1) and a reduction in the hyperphosphorylated form of retinoblastoma protein ( pRB ) . With YCU-N861 cells , ATRA also caused a decrease in Bcl-2 and Bcl-X(L) and an increase in Bax . Both ATRA and 5-FU activated c-Jun N-terminal kinase ( JNK ) 1 and the combination of both agents resulted in additive or synergistic activation of JNK1 , and also enhanced the induction of apoptosis . The YCU-H891 cells , in which the epidermal growth factor receptor ( EGFR)-signal transducer and activator of transcription 3 ( Stat3 ) pathway is constitutively activated , were more resistant to treatments with ATRA , 5-FU and the combination of both agents than YCU-N861 cells . A dominant negative Stat3 construct strongly enhanced the cellular sensitivity of this cell line to 5-FU but not to ATRA . In addition there is evidence that activation of Stat3 is associated with cellular resistance to radiation in HNSCC . Therefore , the addition to FAR therapy of agents that inhibit activation of the Stat3 pathway may enhance the clinical response of patients with HNSCC to FAR therapy .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
11927016
|
OBJECTIVE : Emerging evidences implicate long noncoding RNAs ( lncRNAs ) are deregulated in cancer development . The purpose of the current study is to investigate the role of new lncRNA , named PlncRNA-1 , in prostate cancer ( CaP ) pathogenesis . MATERIALS AND METHODS : In this study , real-time q-PCR was used to demonstrate the expression of PlncRNA-1 in 16 pairs CaP tissues and matched normal tissues , 14 pairs CaP tissues and BPH tissues , 4 CaP cell lines , including LNCaP , LNCaP-AI , PC3 , and C4-2 , and 2 normal prostate epithelial cell lines RWPE-1 and PWR-1E . After PlncRNA-1 was suppressed by siRNA in LNCaP and LNCaP-AI cell lines , cell proliferation and apoptosis were assessed using CCK-8 and terminal deoxynucleotidyl transferase dUTP nick end labeling ( TUNEL ) . After PlncRNA-1 and AR was suppressed by siRNA in LNCaP and LNCaP-AI cell lines , real-time q-PCR and Western blotting were used to measure reciprocal regulation of PlncRNA-1 and AR . RESULTS : We showed that expression PlncRNA-1 , was significantly higher in CaP cells relative to normal prostate epithelial cells , as well as higher in human CaPs compared with normal tissues and benign prostatic hyperplasia ( BPH ) . Silencing of PlncRNA-1 significantly reduced cell proliferation and induced apoptosis in CaP cell lines LNCaP and LNCaP-AI . Mechanistically , PlncRNA-1 suppression by siRNA resulted in a decrease of androgen receptor ( AR ) mRNA , protein and AR downstream target . Of note , blockade of AR signaling with siRNA also resulted in a suppression of PlncRNA-1 expression in CaP cell lines . CONCLUSIONS : Our study suggests reciprocal regulation of PlncRNA-1 and androgen receptor contribute to CaP pathogenesis and that PlncRNA-1 is a potential therapy target .
|
[
0,
0,
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0,
0,
0,
0,
1,
1,
0
] |
22264502
|
BACKGROUND Advancing age is associated with substantial increases in the incidence rates of common diseases affecting the prostate gland including benign prostatic hyperplasia ( BPH ) and prostate carcinoma . The prostate is comprised of a functional secretory epithelium , a basal epithelium , and a supporting stroma comprised of structural elements , and a spectrum of cell types that includes smooth muscle cells , fibroblasts , and inflammatory cells . As reciprocal interactions between epithelium and stromal constituents are essential for normal organogenesis and serve to maintain normal functions , discordance within the stroma could permit or promote disease processes . In this study we sought to identify aging-associated alterations in the mouse prostate microenvironment that could influence pathology . METHODOLOGY/PRINCIPAL FINDINGS We quantitated transcript levels in microdissected glandular-adjacent stroma from young ( age 4 months ) and old ( age 20-24 months ) C57BL/6 mice , and identified a significant change in the expression of 1259 genes ( p<0.05 ) . These included increases in transcripts encoding proteins associated with inflammation ( e.g. , Ccl8 , Ccl12 ) , genotoxic/oxidative stress ( e.g. , Apod , Serpinb5 ) and other paracrine-acting effects ( e.g. , Cyr61 ) . The expression of several collagen genes ( e.g. , Col1a1 and Col3a1 ) exhibited age-associated declines . By histology , immunofluorescence , and electron microscopy we determined that the collagen matrix is abundant and disorganized , smooth muscle cell orientation is disordered , and inflammatory infiltrates are significantly increased , and are comprised of macrophages , T cells and , to a lesser extent , B cells . CONCLUSION/SIGNIFICANCE These findings demonstrate that during normal aging the prostate stroma exhibits phenotypic and molecular characteristics plausibly contributing to the striking age associated pathologies affecting the prostate .
|
[
0,
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0,
0,
0,
0,
0,
0,
0,
1
] |
20824135
|
MicroRNAs ( miRNAs ) are considered to be regulators of various biological processes in cancers , including the epithelial to mesenchymal transition ( EMT ) , which is a key factor in cancer metastasis . In this study , we aimed to clarify the potential roles of miR-490-3p in hepatocellular carcinoma ( HCC ) cells . Using real-time quantitative RT-PCR , we discovered that miR-490-3p was up-regulated in HCC tissues and cells compared with the adjacent non-tumor tissues and normal cells . We also found that overexpression of miR-490-3p led to an increase in cell proliferation , migration , and invasion abilities and that it contributed to EMT . The inhibition of miR-490-3p had the opposite effect on the cells . We identified ERGIC3 ( endoplasmic reticulum-Golgi intermediate compartment protein 3 ) as a direct target gene for miR-490-3p . Unlike most miRNA-mRNA interactions , miR-490-3p increased ERGIC3 mRNA and protein levels as well as the intensity of expression of the EGFP reporter gene controlled by the 3'-UTR of ERGIC3 mRNA . The up-regulation by miR-490-3p also required the participation of Ago2 . The inhibition of miR-490-3p reduced the expression of ERGIC3 . Overexpression of ERGIC3 led to the same effect on HCC cells as miR-490-3p overexpression , including EMT . Importantly , silencing ERGIC3 reversed the cellular responses mediated by miR-490-3p overexpression . In conclusion , our study indicated for the first time that miR-490-3p functioned like an oncogenic miRNA in HCC cells and that the inhibition of miR-490-3p might provide an potential treatment approach for HCC patients .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23212913
|
Toll-like receptor 2 ( TLR2 ) is a target for immune system stimulation during cancer immunotherapy and a cell-surface marker for pancreatic cancer . To develop targeted agents for cancer imaging and therapy , we designed , synthesized , and characterized 13 novel , fully synthetic high affinity TLR2 agonists . Analogue 10 had the highest agonist activity ( NF-κB functional assay , EC(50) = 20 nM ) and binding affinity ( competitive binding assay , K(i) = 25 nM ) . As an immune adjuvant , compound 10 stimulated the immune system in vivo by generation and persistence of antigen-specific CD8+ T cells indicating its potential use in cancer immunotherapy . After conjugation of near-infrared dye to 10 , agonist activity ( EC(50) = 34 nM ) and binding affinity ( K(i) = 11 nM ) were retained in 13 . Fluorescence signal was present in TLR2 expressing pancreatic tumor xenografts 24 h after injection of 13 , while an excess of unlabeled ligand blocked 13 from binding to the tumor , resulting in significantly decreased signal ( p < 0.001 ) demonstrating in vivo selectivity .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23098072
|
Approximately 50% of melanomas require oncogenic B-RAF(V600E) signaling for proliferation , survival , and metastasis , and the use of highly selective B-RAF inhibitors has yielded remarkable , although short-term , clinical responses . Reactivation of signaling downstream of B-RAF is frequently associated with acquired resistance to B-RAF inhibitors , and the identification of B-RAF targets may therefore provide new strategies for managing melanoma . In this report , we applied whole-genome expression analyses to reveal that oncogenic B-RAF(V600E) regulates genes associated with epithelial-mesenchymal transition in normal cutaneous human melanocytes . Most prominent was the B-RAF-mediated transcriptional repression of E-cadherin , a keratinocyte-melanoma adhesion molecule whose loss is intimately associated with melanoma invasion and metastasis . Here we identify a link between oncogenic B-RAF , the transcriptional repressor Tbx3 , and E-cadherin . We show that B-RAF(V600E) induces the expression of Tbx3 , which potently represses E-cadherin expression in melanocytes and melanoma cells . Tbx3 expression is normally restricted to developmental embryonic tissues and promoting cell motility , but it is also aberrantly increased in various cancers and has been linked to tumor cell invasion and metastasis . We propose that this B-RAF/Tbx3/E-cadherin pathway has a critical role in promoting the metastasis of B-RAF-mutant melanomas .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23190890
|
Cellular redox changes have emerged as a pivotal and proximal event in cancer . PKI 166 is used to determine the effects of redox sensitive inhibition of EGFR , metastasis and apoptosis in epidermoid carcinoma . Cytotoxicity study of PKI 166 ( IC50 1.0 microM ) treated A431 cells were performed by MTT assay for 48 and 72 hrs . Morphological analysis of PKI 166 treated A431 cells for 48 hrs. revealed the cell shrinkage , loss of filopodia and lamellipodia by phase contrast and SEM images in dose dependent manner . It has cytotoxic effects through inhibiting cellular proliferation , leads to the induction of apoptosis , as increased fraction of sub-G1 phase of the cell cycle , chromatin condensation and DNA ladder . It inhibited cyclin-D1 and cyclin-E expression and induced p53 , p21 expression in dose dependent manner . Consequently , an imbalance of Bax/Bcl-2 ratio triggered caspase cascade and subsequent cleavage of PARP , thereby shifting the balance in favour of apoptosis . PKI 166 treatment actively stimulated reactive oxygen species ( ROS ) and mitochondrial membrane depolarization . It inhibited some metastatic properties of A431 cells supressing colony formation by soft agar assay and inhibition of MMP 9 activity by gelatin zymography and western blot analysis . PKI 166 inhibited growth factor induced phosphorylation of EGFR , Akt , MAPK , JNK and colony formation in A431 cells . Thus the inhibition of proliferation was associated with redox regulation of the caspase cascade , EGFR , Akt/PI3K , MAPK/ ERK and JNK pathway . On the other hand , increased antioxidant activity leads to decreased ROS generation inhibit the anti-proliferative and apoptotic properties of PKI 166 in A431 cells . These observations indicated PKI 166 induced redox signalling dependent inhibition of cell proliferation , metastatic properties and induction of apoptotic potential in epidermoid carcinoma .
|
[
1,
0,
0,
0,
1,
0,
0,
1,
1,
1
] |
23350354
|
Schizophrenia is a complex mental disorder with high degree of genetic influence in its etiology . Several recent studies revealed that copy number variations ( CNVs ) of genomic DNA contributed significantly to the genetic architecture of sporadic schizophrenia . This study aimed to investigate whether CNVs also contribute to the familial forms of schizophrenia . Using array-based comparative genomic hybridization technology , we searched for pathogenic CNV associated with schizophrenia in a sample of 60 index cases from multiplex schizophrenia families . We detected three inherited CNVs that were associated with schizophrenia in three families , including a microdeletion of at chromosome 6q12-q13 , a microduplication of at chromosome 18q12.3 , and an interstitial duplication of at chromosome 15q11.2-q13.1 . Our data indicate that CNVs contribute to the genetic underpinnings of the familial forms of schizophrenia as well as of the sporadic form . As 15q11-13 duplication is a well-known recurrent CNV associated with autism in the literature , the detection of the 15q11.2-q13.1 duplication in our schizophrenia patients provides additional support to other studies reporting that schizophrenia is part of the clinical spectrum of 15q11-q13 duplication syndrome .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22682706
|
The effects of deoxycholic acid ( DCA ) and ursodeoxycholic acid ( UDCA ) on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine ( PhIP)-induced aberrant crypt foci ( ACF ) in the rat colon were examined . The effect of these bile acids on DNA adduct formation by PhIP in the colon was then analyzed , since the main action of PhIP is the formation of DNA adducts and subsequent gene mutations . For the ACF study , male F344 rats were administered PhIP-HCl ( 75 mg/kg , 10 doses ) by gavage , and a diet containing bile acid ( 0.4% DCA or UDCA ) was provided from 3 days before the first dose of PhIP for 8 weeks . The mean number of ACF per colon of DCA , UDCA and controls were 9.9 , 2.4 and 5.5 , respectively . The ACF number was significantly increased by DCA and decreased by UDCA ( P<0.001 ) . To examine the effect of bile acids on DNA adduct formation , male F344 rats were fed a diet supplemented with bile acids ( 0.1 or 0.4% of DCA and UDCA ) 7 days prior to the PhIP administration . All rats were administered a single dose of PhIP-HCl ( 50 mg/kg ) by gavage and sacrificed 48 hours later . DNA adduct levels of the 0.1% UDCA , 0.1% DCA and controls were 2.93 ( adducts/10(7) nucleotides ) , 2.65 and 1.10 , respectively . Those of 0.4% UDCA , 0.4% DCA and controls were 1.64 , 1.30 and 1.00 , respectively . The PhIP-DNA adduct level was significantly increased by administration of 0.1% UDCA , 0.1% DCA ( P<0.05 ) and 0.4% UDCA ( P<0.01 ) . The increasing effect of both DCA and UDCA on PhIP-induced DNA adduct formation was unexpected , and was not directly associated with ACF formation .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
12636105
|
OBJECTIVE As we previously demonstrated , the inhibitory effect of iodine on thyroid cell growth is mediated by iodolactones , especially 6-iodo-5-hydroxy-eicosatrienoic acid ( delta-iodolactone ) . In this communication we compare the effect of iodide , molecular iodine and delta-iodolactone on growth inhibition and apoptosis on three human thyroid carcinoma cell lines ( B-CPAP cells , FTC-133 cells and 8505C cells ) as well as on human breast cancer cells ( MCF 7 ) . METHODS Thyroid carcinoma cells were cultured in Dulbecco's modified Eagle's medium ( DMEM ) and MCF 7 cells in Rowswell Park Memorial Institute ( RPMI ) culture medium , both containing 10% ( v/v ) Fetal Calf Serum ( FCS ) , until they were confluent . Around 2000 cells were then distributed in 12-well plates and grown for 48 h in either DMEM ( thyroid cancer cells ) or in RPMI medium ( MCF 7 cells ) both containing 5% FCS . Thereafter , different concentrations of iodide , iodine or delta-iodolactone were added for 24 h . Growth rate was estimated by cell counting in a Coulter Counter adapted for epithelial cells . Apoptosis was determined by a mitochondrial potential assay . RESULTS The growth rate of B-CPAP cells was unaffected by iodide , but was reduced by high concentreations of molecular iodine ( 100 and 500 microM ) . However , delta-iodolactone significantly reduced cell proliferation already with low concentrations ( 5 microM and 10 microM ) and further in a dose-dependent manner up to 82% . FTC-133 and 8505C cells were unaffected by iodide , iodine or delta-iodolactone . In contrast , in MCF 7 cells , molecular iodine ( 100 microM ) inhibited growth from 100% to 83% but delta-iodolactone ( 1 , 5 and 10 microM ) dose-dependently decreased growth rate from 100% to 82% and 62% , respectively . The inhibition of growth was through apoptosis , and not necrosis , as the amount of apoptotic cells corresponded to the growth inhibition . CONCLUSION delta-Iotaodolactone seems to be the main iodocompound which can inhibit growth and induce apoptosis in B-CPAP cells as well as in MCF 7 breast cancer cells .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20363723
|
Integrin \u03b1v\u03b23 plays a role in insulin-like growth factor 1 ( IGF1 ) signaling ( integrin-IGF1 receptor ( IGF1R ) cross-talk ) in non-transformed cells in anchorage-dependent conditions . We reported previously that IGF1 directly binds to \u03b1v\u03b23 and induces \u03b1v\u03b23-IGF1-IGF1R ternary complex formation in these conditions . The integrin-binding defective IGF1 mutant ( R36E/R37E ) is defective in inducing ternary complex formation and IGF signaling , whereas it still binds to IGF1R . We studied if IGF1 can induce signaling in anchorage-independent conditions in transformed Chinese hamster ovary cells that express \u03b1v\u03b23 ( \u03b23-CHO ) cells . Here we describe that IGF1 signals were more clearly detectable in anchorage-independent conditions ( polyHEMA-coated plates ) than in anchorage-dependent conditions . This suggests that IGF signaling is masked by signals from cell-matrix interaction in anchorage-dependent conditions . IGF signaling required \u03b1v\u03b23 expression , and R36E/R37E was defective in inducing signals in polyHEMA-coated plates . These results suggest that \u03b1v\u03b23-IGF1 interaction , not \u03b1v\u03b23-extracellular matrix interaction , is essential for IGF signaling . Inhibitors of IGF1R , Src , AKT , and ERK1/2 did not suppress \u03b1v\u03b23-IGF-IGF1R ternary complex formation , suggesting that activation of these kinases are not required for ternary complex formation . Also , mutations of the \u03b23 cytoplasmic tail ( Y747F and Y759F ) that block \u03b23 tyrosine phosphorylation did not affect IGF1R phosphorylation or AKT activation . We propose a model in which IGF1 binding to IGF1R induces recruitment of integrin \u03b1v\u03b23 to the IGF-IGF1R complex and then \u03b23 and IGF1R are phosphorylated . It is likely that \u03b1v\u03b23 should be together with the IGF1-IGF1R complex for triggering IGF signaling .
|
[
0,
0,
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0,
1,
0,
0,
1,
0
] |
23243309
|
It is crucial for organ homeostasis that epithelia have effective mechanisms to restrict motility and cell proliferation in order to maintain tissue architecture . On the other hand , epithelial cells need to rapidly and transiently acquire a more mesenchymal phenotype , with high levels of cell motility and proliferation , in order to repair epithelia upon injury . Cross talk between cell-cell and cell-matrix signaling is crucial for regulating these transitions . The Pak1-betaPIX-GIT complex is an effector complex downstream of the small GTPase Rac1 . We previously showed that translocation of this complex from cell-matrix to cell-cell adhesion sites was required for the establishment of contact inhibition of proliferation . In this study , we provide evidence that this translocation depends on cadherin function . Cadherins do not recruit the complex by direct interaction . Rather , we found that inhibition of the normal function of cadherin or Pak1 leads to defects in focal adhesion turnover and to increased signaling by phosphatidylinositol 3-kinase . We propose that cadherins are involved in regulation of contact inhibition by controlling the function of the Pak1-betaPIX-GIT complex at focal contacts .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
20154149
|
INTRODUCTION IκB Kinase ε ( IKKε ) is a member of the IKK family which plays an important role in the activation of nuclear factor-κB ( NF-κB ) . Overexpressed in over 30% of breast cancers , IKKε has been recently identified as a potential breast cancer oncogene . The purpose of this study is to examine the therapeutic potential of IKKε siRNA on human breast cancer cells . METHODS Eight siRNAs targeting different regions of the IKKε mRNA were designed , and the silencing effect was screened by quantitative real time RT-PCR . The biological effects of synthetic siRNAs on human breast cancer cells were investigated by examining the cell proliferation , migration , invasion , focus formation , anchorage-independent growth(via soft agar assay ) , cell cycle arrest , apoptosis ( via annexing binding ) , NF-κB basal level , and NF-κB related gene expressions upon the IKKε silencing . RESULTS Silencing of IKKε in human breast cancer cells resulted in decrease of focus formation potential and clonogenicity as well as in vitro cell migration/invasion capabilities . Moreover , knockdown of IKKε suppressed cell proliferation . Cell cycle assay showed that the anti-proliferation effect of IKKε siRNA was mediated by arresting cells in G(0)/G(1) phase , which was caused by down-regulation of cyclin D(1) . Furthermore , we demonstrated that silencing of IKKε inhibited the NF-κB basal activity as well as the Bcl-2 expression . Significant apoptosis was not observed in breast cancer cells upon the silencing of IKKε . The present study provided the first evidence that silencing IKKε using synthetic siRNA could inhibit the invasiveness properties and proliferation of breast cancer cells . CONCLUSIONS Our results suggested that silencing IKKε using synthetic siRNA may offer a novel therapeutic strategy for breast cancer .
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[
1,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
20863366
|
Insulin-like growth factor ( IGF)-I receptor ( IGF-IR ) signaling is required for carcinogenicity and progression of several cancers but the function of this pathway and its utility as a therapeutic target have not been studied comprehensively in biliary tract carcinomas ( BTC ) . We investigated the immunohistochemical expression of elements of the IGF axis , matrilysin , overexpression of p53 and the methylation status of the IGFBP-3 promoter in 80 surgically resected BTC . We also assessed the effect of IGF-IR blockade on signal transduction , proliferation and survival in three BTC cell lines using a new tyrosine kinase inhibitor , BMS-536924 , and dominant negative IGF-IR ( IGF-IR/dn ) . The effects of IGF-IR blockade was also studied in nude mouse xenograft models . IGF-I was expressed in 60% and IGF-II in 50% of tumors . High expression was associated with tumor size . IGF-IR was expressed in 69% of the cases and was associated with advanced stage and matrilysin expression . Hypermethylation of the IGFBP-3 promoter was detected in 41% of BTC and was inversely correlated with p53 expression . BMS-536924 blocked autophosphorylation of IGF-IR and both Akt and ERK activation by both IGF-I and insulin . BMS-536924 suppressed proliferation and tumorigenicity in vitro in a dose-dependent fashion . This inhibitor upregulated chemotherapy-induced apoptosis in a dose-dependent fashion . Moreover , IGF-IR blockade was effective against tumors in mice . IGF-IR might identify a subset of BTC with a particularly aggressive phenotype and is a candidate therapeutic target in this disease . BMS-536924 might have significant therapeutic utility .
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[
0,
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0,
0,
0,
0,
0,
1,
0,
0
] |
22044563
|
PURPOSE The ability to accurately predict the likelihood of expansion of the CGG repeats in the FMR1 gene to a full mutation is of critical importance for genetic counseling of women who are carriers of premutation alleles ( 55-200 CGG repeats ) and who are weighing the risk of having a child with fragile X syndrome . The presence of AGG interruptions within the CGG repeat tract is thought to decrease the likelihood of expansion to a full mutation during transmission , thereby reducing risk , although their contribution has not been quantified . METHODS We retrospectively analyzed 267 premutation alleles for number and position of AGG interruptions , length of pure CGG repeats , and CGG repeat lengths present in the offspring of the maternal transmissions . In addition , we determined the haplotypes of four markers flanking the 5'-UTR locus in the premutation mothers . RESULTS We found that the presence of AGG interruptions significantly increased genetic stability , whereas specific haplotypes had a marginal association with transmission instability . CONCLUSION The presence of AGG interruptions reduced the risk of transmission of a full mutation for all maternal ( premutation ) repeat lengths below CGG repeats , with a differential risk ( 0 vs. 2 AGG ) exceeding 60% for alleles in the 70- to 80-CGG repeat range .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22498846
|
The involvement of PRL in regulating monocyte/macrophage functions is suggested by the presence of PRL-Rs in these cells . Here , we show that PRL , though it failed to activate mouse peritoneal resident macrophages ( RMs ) , acted as a second signal and activated mouse peritoneal inflammatory macrophages ( EMs ) to a tumoricidal state . The cytotoxicity of mouse tumor-associated macrophages ( TAMs ) isolated at day 1 of tumor ( Ehrlich ascites carcinoma , EAC ) growth was enhanced by PRL . However , with progression of tumor growth , TAMs became nonresponsive to the hormone . PRL-induced killing of P815 target cells by EMs and TAMs was independent of TNF but correlated with the hormone-induced augmentation of NO2(-) and O2(-) release in these macrophages . Administration of PRL in vivo inhibited EAC growth and augmented NO2(-) release by TAMs . PRL synergized with the TH1 cytokine IFN-gamma , a known activator of macrophages , in inducing tumor killing and release of NO2(-) from EMs and TAMs . The hormone might activate macrophages at least partially , through the release of IFN-gamma as anti-IFN-gamma blocked IFN-gamma- as well as PRL-induced cytotoxicity in EMs . The TH2 cytokine IL-4 suppressed PRL-induced activation of macrophages . PRL induced release of IL-12 from EMs also , which suggested that the hormone might drive the TH1 response through IL-12 . Our observations further suggest that PRL alone and in synergy with IFN-gamma , released through induction of IL-12 , may generate tumoricidal macrophages and thus regulate the antitumor immune response of tumor hosts .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
11802212
|
Rhabdoid tumors have been reported in many different anatomic sites as an aggressive tumor and usually present with a rhabdoid tumor component ( a composite tumor ) rather than a pure rhabdoid tumor . Rhabdoid tumor in the prostate has been described only once in the prostatic region as a possible epithelial origin . Rhabdoid features in prostatic stromal sarcomas ( PSSs ) have never been described in the literature . Here , we report a case of a PSS with rhabdoid features . A 31-year-old man presented with a 4-month history of voiding difficulty and anal pain . Computed tomography of the abdomen revealed an ovoid mass in the prostate invading rectum and urinary bladder . A needle biopsy was diagnosed as an unclassified spindle cell sarcoma , and 2 cycles of adriamycin-based neoadjuvant chemotherapy were given , followed by radical prostatectomy . The prostatectomy specimen revealed a high-grade sarcoma with fascicles of highly cellular spindle cells and numerous mitoses with hemorrhage and necrosis . In areas , the tumor also contained sheets of loosely cohesive epithelioid cells with rhabdoid tumor component . Both spindle and rhabdoid tumor cells were positive for vimentin , CD34 , and progesterone receptor and negative for desmin and cytokeratin immunostainings . The rhabdoid tumor cells retained INI1 expression . The tumor recurred in the bladder , and the patient died of sepsis . To the best of our knowledge , this is the first case of PSS with rhabdoid features . The tumor showed an aggressive clinical behavior with a short-term survival ( 7 months after diagnosis ) .
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[
0,
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0,
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0,
1,
0,
0
] |
21074696
|
The relationship between DNA damage and repair of peripheral blood leukocytes , liver , kidney and brain cells was investigated in Swiss albino mice ( Mus musculus L. ) after exposure to sevoflurane ( 2.4 vol% for 2 h daily , for 3 days ) . Genetic damage of mouse cells was investigated by the comet assay and micronucleus test . To perform the comet assay , mice were divided into a control group and 4 groups of exposed mice sacrificed on day 3 of the experiment , at 0 , 2 , 6 or 24 h after the last exposure to sevoflurane . Mean tail length ( TL ) , tail moment ( TM ) , and tail intensity ( TI ) values were significantly higher in exposed mice ( all examined organs ) than in the control group . Significant DNA damage immediately after exposure to sevoflurane was observed in leukocytes . Damage induction in the liver , kidney , and brain occurred 6 h later than in leukocytes , as expected according to the toxicokinetics of the drug , where blood is the first compartment to absorb sevoflurane . However , none of the tested tissues revealed signs of repair until 24 h after the exposure . To distinguish the unrepaired genome damage in vivo , the micronucleus test was applied . Number of micronuclei in reticulocytes showed a statistically significant increase , as compared with the control group at all observed times after the treatment .
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[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20145304
|
Although it has been demonstrated that discrete origins of DNA replication exist in eukaryotic cellular chromosomes , the detailed organization of a eukaryotic cellular origin remains to be determined . Linker substitution mutations were constructed across the entire Saccharomyces cerevisiae chromosomal origin , ARS1 . Functional studies of these mutants revealed one essential element ( A ) , which includes a match to the ARS consensus sequence , and three additional elements ( B1 , B2 , and B3 ) , which collectively are also essential for origin function . These four elements arranged exactly as in ARS1 , but surrounded by completely unrelated sequence , functioned as an efficient origin . Element B3 is the binding site for the transcription factor-origin binding protein ABF1 . Other transcription factor binding sites substitute for the B3 element and a trans-acting transcriptional activation domain is required . The multipartite nature of a chromosomal replication origin and the role of transcriptional activators in its function present a striking similarity to the organization of eukaryotic promoters .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
1536007
|
Cellular senescence forms a barrier that inhibits the acquisition of an immortal phenotype , a critical feature in tumorigenesis . The inactivation of multiple pathways that positively regulate senescence are required for immortalization . To identify these pathways in an unbiased manner , we performed DNA microarray analyses to assess the expression of 20,000 genes in human prostate epithelial cells ( HPECs ) passaged to senescence . These gene expression patterns were then compared with those of HPECs immortalized with the human Papillomavirus 16 E7 oncoprotein . Senescent cells display gene expression patterns that reflect their nonproliferative , differentiated phenotype and express secretory proteases and extracellular matrix components . A comparison of genes transcriptionally up-regulated in senescence to those in which expression is significantly down-regulated in immortalized HPECs identified three genes : the chemokine BRAK , DOC1 , and a member of the insulin-like growth factor axis , IGFBP-3 . Expression of these genes is found to be uniformly lost in human prostate cancer cell lines and xenografts , and previously , their inactivation was documented in tumor samples . Thus , these genes may function in novel pathways that regulate senescence and are inactivated during immortalization . These changes may be critical not only in allowing cells to bypass senescence in vitro but in the progression of prostate cancer in vivo .
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[
0,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
11836256
|
Free radical-induced cellular stress contributes to cancer during chronic inflammation . Here , we investigated mechanisms of p53 activation by the free radical , NO . NO from donor drugs induced both ataxia-telangiectasia mutated ( ATM)- and ataxia-telangiectasia mutated and Rad3-related-dependent p53 posttranslational modifications , leading to an increase in p53 transcriptional targets and a G(2)M cell cycle checkpoint . Such modifications were also identified in cells cocultured with NO-releasing macrophages . In noncancerous colon tissues from patients with ulcerative colitis ( a cancer-prone chronic inflammatory disease ) , inducible NO synthase protein levels were positively correlated with p53 serine 15 phosphorylation levels . Immunostaining of HDM-2 and p21(WAF1) was consistent with transcriptionally active p53 . Our study highlights a pivotal role of NO in the induction of cellular stress and the activation of a p53 response pathway during chronic inflammation .
|
[
0,
0,
0,
0,
1,
1,
0,
0,
0,
1
] |
12518062
|
Vascular endothelial growth factor ( VEGF ) , also known as vascular permeability factor or vasculotropin , is a recently characterized endothelial-specific mitogen which is angiogenic in vivo . Here we demonstrate that VEGF is angiogenic in vitro : when added to microvascular endothelial cells grown on the surface of three-dimensional collagen gels , VEGF induces the cells to invade the underlying matrix and to form capillary-like tubules , with an optimal effect at approximately 2.2nM ( 100ng/ml ) . When compared to basic fibroblast growth factor ( bFGF ) at equimolar ( 0.5nM ) concentrations , VEGF was about half as potent . The most striking effect was seen in combination with bFGF : when added simultaneously , VEGF and bFGF induced an in vitro angiogenic response which was far greater than additive , and which occurred with greater rapidity than the response to either cytokine alone . These results demonstrate that like bFGF , VEGF induces an angiogenic response via a direct effect on endothelial cells , and that by acting in concert , these two cytokines have a potent synergistic effect on the induction of angiogenesis in vitro . We suggest that the synergism between VEGF and bFGF plays an important role in the control of angiogenesis in vivo .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
1281999
|
Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma ( LGNPPA ) is extremely rare ; only four cases have been reported . Herein are presented the case reports of two Japanese male patients with thyroid-like LGNPPA . Macroscopically , these tumors were pedunculated polypoid masses on the roof of the nasopharynx . Microscopically , they were characterized by papillary and glandular epithelial proliferation . The papillae were complex and tightly packed with hyalinized fibrovascular cores and lined by columnar and pseudostratified cells with intervening spindle-shaped cells . Both cell types had round to oval vesicular nuclei with tiny nucleoli and mildly eosinophilic cytoplasm . Mitotic figures were not evident and necrosis was not observed . Psammoma bodies were seen focally in one of the patients . Transition from normal surface epithelium to tumor cells was identified in both cases . On immunohistochemistry the tumor cells were positive for cytokeratin ( CK)7 , CK19 , thyroid transcription factor-1 ( TTF-1 ) and vimentin . They were negative for CK5/6 , CK20 , thyroglobulin , S-100 protein and CD15 . In situ hybridization for EBV was negative . Nasopharyngeal tumors with similar morphological appearance should be examined for TTF-1 immunoreactivity , and patients should be clinically followed to determine the course of this unusual disease and the significance of TTF-1 expression .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20398195
|
BACKGROUND The importance of cell-surface nucleolin in cancer biology was recently highlighted by studies showing that ligands of nucleolin play critical role in tumorigenesis and angiogenesis . By using a specific antagonist that binds the C-terminal tail of nucleolin , the HB-19 pseudopeptide , we recently reported that HB-19 treatment markedly suppressed the progression of established human breast tumor cell xenografts in the athymic nude mice without apparent toxicity . METHODS The in vivo antitumoral action of HB-19 treatment was assessed on the spontaneous development of melanoma in the RET transgenic mouse model . Ten days old RET mice were treated with HB-19 in a prophylactic setting that extended 300 days . In parallel , the molecular basis for the action of HB-19 was investigated on a melanoma cell line ( called TIII ) derived from a cutaneous nodule of a RET mouse . RESULTS HB-19 treatment of RET mice caused a significant delay in the onset of cutaneous tumors , several-months delay in the incidence of large tumors , a lower frequency of cutaneous nodules , and a reduction of visceral metastatic nodules while displaying no toxicity to normal tissue . Moreover , microvessel density was significantly reduced in tumors recovered from HB-19 treated mice compared to corresponding controls . Studies on the melanoma-derived tumor cells demonstrated that HB-19 treatment of TIII cells could restore contact inhibition , impair anchorage-independent growth , and reduce their tumorigenic potential in mice . Moreover , HB-19 treatment caused selective down regulation of transcripts coding matrix metalloproteinase 2 and 9 , and tumor necrosis factor-alpha in the TIII cells and in melanoma tumors of RET mice . CONCLUSIONS Although HB-19 treatment failed to prevent the development of spontaneous melanoma in the RET mice , it delayed for several months the onset and frequency of cutaneous tumors , and exerted a significant inhibitory effect on visceral metastasis . Consequently , HB-19 could provide a novel therapeutic agent by itself or as an adjuvant therapy in association with current therapeutic interventions on a virulent cancer like melanoma .
|
[
1,
0,
0,
0,
1,
0,
1,
0,
0,
0
] |
20573279
|
During the course of inflammation and its resolution , macrophages are exposed to various cytotoxic materials , including reactive oxygen species . Thus , macrophages require a protective machinery against oxidative stress to survive at the inflammatory site . Here , we showed that xCT , a component of transport system x(c)(-) , was significantly up-regulated in activated infiltrating cells , including macrophages and neutrophils at the inflammatory site . System x(c)(-) mediates the uptake of extracellular L-cystine and is consequently responsible for maintenance of intracellular glutathione levels . We established a loss-of-function mouse mutant line of xCT by N-ethyl-N-nitrosourea mutagenesis . Macrophages from xCT(mu/mu) mice showed cell death in association with the excessive release of high mobility group box chromosomal protein 1 upon stimulation with LPS , suggesting that xCT deficiency causes unremitting inflammation because of the impaired survival of activated macrophages at the inflammatory site . Subcutaneous injection of 3-methylcholanthrene ( 3-MCA ) induced the generation of fibrosarcoma in association with inflammation . When 3-MCA was injected s.c. into mice , xCT mRNA was up-regulated in situ . In xCT(mu/mu) mice , inflammatory cytokines ( such as IL-1beta and TNFalpha ) were overexpressed , and the generation of 3-MCA-induced fibrosarcoma was accelerated . These results clearly indicate that the defect of the protective system against oxidative stress impaired survival of activated macrophages and subsequently enhanced tumorigenecity .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
20308543
|
DNA double strand breaks ( DSBs ) arise from spontaneous DNA damage due to metabolic activities or from direct and indirect damaging effects of stress . DSBs are also formed transiently during such processes as replication , transcription , and DNA repair . The level of DSBs positively correlates with the activities of homologous and nonhomologous DNA repair pathways , which in turn inversely correlate with methylation levels and chromatin structure . Thus , measurement of strand breaks can provide an informative picture of genome stability of a given cell . The use of random oligonucleotide-primed synthesis for the analysis of DSB levels is described . Applications of the assay for quantitative detection of 3'OH , 3'P , or DNA strand breaks at a cleavage site of the deoxyribose residue are discussed .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20204879
|
Congenital gonadotropin-releasing hormone ( GnRH ) deficiency manifests as absent or incomplete sexual maturation and infertility . Although the disease exhibits marked locus and allelic heterogeneity , with the causal mutations being both rare and private , one causal mutation in the prokineticin receptor , PROKR2 L173R , appears unusually prevalent among GnRH-deficient patients of diverse geographic and ethnic origins . To track the genetic ancestry of PROKR2 L173R , haplotype mapping was performed in 22 unrelated patients with GnRH deficiency carrying L173R and their 30 first-degree relatives . The mutation's age was estimated using a haplotype-decay model . Thirteen subjects were informative and in all of them the mutation was present on the same kb haplotype whose population frequency is \u226410% . Thus , PROKR2 L173R represents a founder mutation whose age is estimated at approximately 9000 years . Inheritance of PROKR2 L173R-associated GnRH deficiency was complex with highly variable penetrance among carriers , influenced by additional mutations in the other PROKR2 allele ( recessive inheritance ) or another gene ( digenicity ) . The paradoxical identification of an ancient founder mutation that impairs reproduction has intriguing implications for the inheritance mechanisms of PROKR2 L173R-associated GnRH deficiency and for the relevant processes of evolutionary selection , including potential selective advantages of mutation carriers in genes affecting reproduction .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22773735
|
OBJECTIVE To study the relationship between clinical pathologic characteristics , treatment modalities and prognostic factors in HER-2 ( Human Epidermal growth factor Receptor-2 ) overexpressed breast carcinoma . MATERIALS AND METHODS Major clinico-pathological factors including therapeutic modalities and survival status of 371 breast cancer patients with HER2 over-expression , teated at Yantai Yuhuangding Hospital from March of 2002 to December of 2010 were retrospectively studied , with special attention focused on survival-related factors . RESULTS The median age of the total 371 patients in this study was 48 years at time of diagnosis , among which , the leading pathological type was infiltrating ductal carcinoma ( 92.5% ) ; 62.8% presented with a primary tomor larger than 2 cm in diameter at diagnosis , 51.0% had axillary lymph node ( ALN ) metastases ; ER ( Estrogen receptor ) /PR ( Progesterone receptor ) double negative occured in 52.8% of cases , and PCNA ( proliferation cell nuclear antigen ) ( + + + ) was found in 55.1% . HER-2 overexpressed patients were usually in advanced stage when the diagnosis was made ( 72.8% at stages IIA The prognosis and survival were assessed in 259 patients with complete follow-up data. 5-year DFS ( disease-free survival ) and OS ( overall survival ) rate was 68.0% and 78.0% respectively . Univariate analysis revealed that age , tumor size , ALN metastases , LVSI ( lymph-vascular space involvement ) , PCNA status , hormonal therapy , chemotherapy cycles , and HER-2 overexpression , correlated closely with the prognosis . ALN metastases , LVSI , PCNA status and chemotherapy cycles were independent predictors of survival . CONCLUSIONS HER-2 overexpressed breast cancer has special clinical and pathological characteristics , with advanced clinical stages and high rate of ER/PR double negative . Lymph node metastases , LVSI , PCNA and chemotherapy cycles are independent predictors of prognosis .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22799305
|
The effect of peptides released during the fermentation of milk on the humoral immune system and on fibrosarcoma growth was studied . Lactobacillus helveticus was able to release peptidic compounds during milk fermentation due to its high proteolytic activity , as was shown by the degree of proteolysis and size-exclusion HPLC elution profiles . Three fractions of these compounds were separated and fed to mice during different periods ( 2 , 5 , and 7 d ) . The humoral immune response was assessed by following the number of IgA-secreting cells , and the antitumor activity was monitored by studying the regression of subcutaneously implanted fibrosarcomas . Feeding during 2 and 7 d with the medium-sized fraction ( Fraction II ) significantly increased the IgA-producing cells in the intestines , whereas feeding with the large compound fraction ( Fraction I ) during 5 d and the small compound fraction ( Fraction III ) during all three feeding periods provided similar increases . A double dose of Fraction II showed the highest IgA-producing cell count . The increase by Fraction III was shown to be caused by the presence of L-Tryptophan . Fraction II significantly decreased the size of fibrosarcoma when previously fed during 7 d , and feeding with Fraction I during 5 d decreased significantly its size after 35 d of growth . Although the mechanisms by which lactic acid bacteria enhance the immune system are not clear , this study clearly shows that bioactive compounds released in fermented milks contribute to the immunoenhancing and antitumor properties of these products . The release of bioactive peptides by lactic acid bacteria can have important implications on the modulation of the cellular immune response .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
12487440
|
Designed from a high throughput screened hit compound , novel 2-amino-1-thiazolyl imidazoles were synthesized and demonstrated cytotoxicity against human cancer cells. 1-(4-Phenylthiazol-2-yl)-4-(thiophen-2-yl)-1H-imidazol-2-amine ( compound 2 ) , a 2-amino-1-thiazolyl imidazole , inhibited tubulin polymerization , interacted with the colchicine-binding sites of tubulins , and caused cell cycle arrest at the G(2)/M phase in human gastric cancer cells . Disruption of the microtubule structure in cancer cells by compound 2 was also observed . Compound 2 concentration-dependently inhibited the proliferation of cancer cells in histocultured human gastric and colorectal tumors . Given orally , compound 2 prolonged the lifespans of leukemia mice intraperitoneally inoculated with the murine P388 leukemic cells . We report 2-amino-1-thiazolyl imidazoles as a novel class of orally active microtubule-destabilizing anticancer agents .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
20890633
|
BACKGROUND Special AT-rich binding protein-1 ( SATB1 ) reprograms chromatin organization and transcription profiles to promote tumour growth and metastasis . AIMS This study aimed to confirm the effects of SATB1 on the growth and metastasis of liver cancer and its specific regulation mechanism . METHODS SATB1 expression was evaluated in human hepatoma tissue , adjacent noncancerous tissue and seven kinds of liver cancer cell lines . Cell cycle , cell proliferation , apoptosis and epithelial-mesenchymal transition ( EMT ) was investigated after enhanced or silenced expression of SATB1 . The regulatory action of SATB1 on the expression of genes that are known to regulate cell cycle progression , apoptosis and EMT and the specific apoptotic pathway on which it acts were further analysed . Nude mice that received subcutaneous implantation were used to study the effects of SATB1 on tumour growth in vivo . RESULTS Our data show that the high expression of SATB1 was observed in the human hepatocellular carcinoma tissue ( 26/45 ) and liver cancer cell lines with high metastatic potential . SATB1 upregulated CDK4 and downregulated p16 ( INK ) ( 4A ) to promote cell cycle progression and cell proliferation and prevented apoptosis by inhibiting the FADD-caspase-8-caspase-3 death receptor-mediated apoptosis pathway . SATB1 also induced EMT concomitant with increased expression of Snail1 , Slug , Twist and vimentin and decreased expression of E-cadherin , tight junction protein ZO-1 and desmoplakin . SATB1 promoted the growth of tumour in vivo . CONCLUSION These data suggest that the SATB1 gene may play an important role in the development and progression of liver cancer by regulation of genes related to cell cycle progression , apoptosis and EMT .
|
[
1,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
22583549
|
CDKN1C/P57 is a cyclin-dependent kinase inhibitor implicated in different human cancers , including hepatocellular carcinoma ( HCC ) ; however , little is known regarding the role of CDKN1C/P57 and its regulation in HCC . In this study , we show that the down-regulation of Notch1 and Notch3 in two HCC cell lines resulted in Hes1 down-regulation , CDKN1C/P57 up-regulation , and reduced cell growth . In line with these data , we report that CDKN1C/P57 is a target of transcriptional repression by the Notch effector , Hes1 . We found that the up-regulation of CDKN1C/P57 by cDNA transfection decreased tumor growth , as determined by growth curve , flow cytometry analysis , and cyclin D1 down-regulation , without affecting the apoptosis machinery . Indeed , the expression of Bax , Noxa , PUMA , BNIP(3) , and cleaved caspase-3 was not affected by CDKN1C/P57 induction . Morphologically CDKN1C/p57-induced HCC cells became flat and lengthened in shape , accumulated the senescence-associated β-galactosidase marker , and increased P16 protein expression . Evaluation of senescence in cells depleted both for Hes1 and CDKN1C/P57 revealed that the senescent state really depends on the accumulation of CDKN1C/p57 . Finally , we validated our in vitro results in primary HCCs , showing that Hes1 protein expression inversely correlates with CDKN1C/P57 mRNA levels . In addition , reduced Hes1 protein expression is accompanied by a shorter time to recurrence after curative resection , suggesting that Hes1 may represent a biomarker for prediction of patients with poor prognosis .
|
[
0,
0,
0,
1,
0,
0,
0,
1,
0,
0
] |
22705236
|
BACKGROUND & OBJECTIVE There is little ideal predictor available on evaluating the lymph node metastatic potential of breast carcinoma . This study was designed to determine the expression of gene products of E-cadherin ( epithelial ) , N-cadherin ( nerve ) , and matrix metalloproteinase-9 ( MMP-9 ) in breast carcinoma tissue and investigate their association with the invasion and metastasis of breast carcinoma . METHODS The authors examined the expressions of E-cadherin , N-cadherin , and MMP-9 in 72 cases of breast carcinoma(39 cases with lymph node metastasis and 33 cases without lymph node metastasis ) by immunohistochemistry . Multivariable Cox proportional hazards model was used to analyze the patients ' prognosis . RESULTS The average ranks of E-cadherin in lymph node metastasis group and no lymph node metastasis group were 29.19 and 45.14 , respectively , with significant difference ( P < 0.001 ) . The expression of E-cadherin was correlated inversely with the metastasis of breast carcinoma . The average ranks of N-cadherin and MMP-9 were 40.04 and 42.97 in lymph node metastasis group , and 32.32 and 28.85 in no lymph node metastasis group , both with significant difference ( P < 0.05 ) , and these expressions were positively correlated with the lymph node metastasis of breast carcinoma . The patients who had high expression of E-cadherin had a longer survival time . CONCLUSION Expression of E-cadherin , N-cadherin , and MMP-9 are associated strongly with lymph node metastasis of breast carcinoma . These proteins are indicators of metastasis potential and prognosis of breast carcinoma .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
12508543
|
AIM To assess the prognostic significance of nuclear factor-κB ( NF-κB ) and its target genes in gastric cancer . METHODS The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-κB RelA . Preoperative serum levels of vascular endothelial growth factor ( VEGF ) , interleukin-6 ( IL-6 ) were assessed via enzyme-linked immuno-sorbent assay . C-reactive protein ( CRP ) and serum amyloid A ( SAA ) were measured via immunotrubidimetry . RESULTS Positive rate of NF-κB RelA was 42.6% . NF-κB RelA expression in tumor tissues was also related to serum levels of IL-6 ( P = 0.044 ) and CRP ( P = 0.010 ) . IL-6 , SAA , CRP were related to depth of invasion , VEGF and SAA were correlated with lymph node metastasis . IL-6 , VEGF , SAA and CRP were related to the stage . Univariate analysis demonstrated that immunostaining of NF-κB RelA , levels of IL-6 , VEGF , SAA were significantly related with both disease free survival and overall survival ( OS ) . Multivariate analysis verified that NF-κB RelA [ hazard ratio ( HR ) : 3.40 , P = 0.024 ] and SAA ( HR : 3.39 , P = 0.045 ) were independently associated with OS . CONCLUSION Increased expression of NF-κB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23002344
|
At present , isoniazid ( INH ) is being used prophylactically to reduce the side effects of intravesical BCG therapy for superficial bladder cancer , although it is not clear whether or not this reduces the antitumor efficacy of BCG . In this study the impact of INH treatment on the immune response after repeated intravesical BCG administration was investigated in guinea pigs . INH was given on the 3 days around each BCG instillation . We found that the administration of INH severely impaired the immunological effects of BCG . The induction of mononuclear cell infiltration in the bladder wall was reduced . Enlargement of the regional lymph nodes ( weight and number of cells ) , and increase of MHC Class II expression on the lymph node cells , normally observed after intravesical BCG administration , were inhibited by INH . Systemic immunity , measured by the DTH reaction in the skin to PPD , was also diminished due to the combined treatment of BCG with INH . When INH was administered during the last 4 of 6 BCG instillations , the immune response to BCG was still impaired . A five-fold increase of the dose of BCG did not overcome the effect of INH . INH probably did not exert a direct suppression of the immune system of the guinea pig as the DNCB skin reactivity was not influenced . Although INH concentrations in the urine were high at the onset of the instillation , in vitro experiments indicated that the effect of INH may not be caused by killing of the BCG organisms shortly after application in the bladder . In conclusion , our data in guinea pigs suggest that the use of INH may impair the immune response to intravesical BCG . As this response may be important for the antitumor effect of BCG , urologists should be cautious with the prophylactic use of INH . The influence on the antitumor efficacy is now investigated in man .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
1433571
|
In a screen for thoracic malignancy-associated markers , thyroid stimulating hormone receptor ( TSHR ) was identified as a candidate as it binds to the previously-characterized lung cancer marker NKX2-1 . We screened for mutations in all coding regions of the TSHR gene in 96 lung adenocarcinoma samples and their matched adjacent normal lung samples . We found one patient with a somatic mutation at codon 458 ( exon 10 ) , which is located at the transmembrane domain where most TSHR mutations have been found in thyroid-related diseases . This patient had lung adenocarcinoma with BAC ( bronchioloalveolar carcinoma ) features in the setting of a prior medical history significant for carotid stenosis and severe chronic obstructive pulmonary disease ( COPD ) . In order to characterize the genetic features of TSHR in lung cancer , we checked for TSHR expression and copy number in the 96 lung cancer tissues . TSHR protein expression was generally overexpressed in multiple thoracic malignancies ( adenocarcinoma , squamous cell carcinoma and malignant pleural mesothelioma ) by immunohistochemistry . Our data suggest that aberrant TSHR function may contribute to lung cancer development or a subgroup of lung cancer with specific clinical phenotypes .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22842620
|
The evidence that androgen blockade-resistant prostate cancer , termed castration resistant , remains androgen receptor ( AR ) dependent is compelling . AR is re-activated through multiple mechanisms including expression of constitutively active splice variants that lack hormone binding domains ( HBDs ) . This highlights need to develop therapies that target regions other than the HBD . Because the p160 coactivators interact most strongly with the amino-terminus of AR , we examined the consequences of disrupting this interaction . We identified two overlapping SRC-1 peptides that interact with AR , but not with progesterone receptor . These peptides reduce AR and AR variant AR-V7 dependent induction of an AR responsive reporter . Using mammalian two hybrid assays , we found that the peptides interrupt the AR/SRC-1 , AR/SRC-2 and AR N/C interactions , but not SRC-1/CARM-1 interactions . Consistent with the SRC-1 dependence of induced , but not repressed genes , in LNCaP cells , the peptides inhibited hormone dependent induction of endogenous target genes including PSA and TMPRSS2 , but did not block AR dependent repression of UGT2B17 or inhibit vitamin D receptor activity . Simultaneous detection of SRC-1 peptides and PSA by double immunofluorescence in transfected LNCaP cells clearly demonstrated a strong reduction in PSA levels in cells expressing the peptides . The peptides also inhibited the AR dependent expression of PSA in castration resistant C4-2 cells . Moreover they inhibited androgen dependent proliferation of LNCaP cells and proliferation of C4-2 cells in androgen depleted medium without affecting AR negative PC-3 cells . Thus , the p160 coactivator binding site is a novel potential therapeutic target to inhibit AR activity .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
23270728
|
The ras oncogenes alone fully transform established ( immortalized ) rodent fibroblasts in a few days , but generally transform early-passage fibroblasts only partially , unless their action is complemented by that of a nuclear , immortalizing , oncogene . Here we show that transfection of second-passage Syrian hamster embryo fibroblasts ( HEFs ) by the EJ-H-ras oncogene coupled to the neo gene , followed by selection with G418 , gives rise to apparently normal , or only slightly transformed , clonal colonies , only a few of which become established . The study of two established clonal lines showed that they acquired only after some weeks , and stepwise , the main characteristics of full neoplastic transformation , i.e. anchorage independence , reduced requirement for serum growth factors and tumorigenicity . Later both clonal lines became increasingly tumorigenic and completely independent of exogenous growth and attachment factors , without increase in the expression of the H-ras oncogene . Transfection of one of the clones , early after its isolation , with a truncated derivative of the nuclear v-myb oncogene devoid of its transcriptional negative regulatory domain and able to partially transform chicken embryo fibroblasts [ (myb(KXANM) ] gave rise to more transformed cells , expressing both EJ-H-ras and myb(KXANM) , which became tumorigenic earlier than the controls and remained more tumorigenic later on . With more efficient transfection techniques , numerous foci of fully transformed cells were subsequently obtained , in a few days , in cultures transfected sequentially with EJ-H-ras(neo) and myb(KXANM) and in cultures co-transfected with the two oncogenes . Highly tumorigenic , serum-independent and immortalized clones expressing both oncogenes were obtained from these cultures . Hence , the truncated myb(KXANM) oncogene accelerate the stepwise transformation of unestablished HEFs by the EJ-HH-ras oncogene and , together with this oncogene , fully transforms these same cells in a single step . The two oncogenes acting in cooperation also induce cell immortalization , but myb(KXANM) , by itself , is not an immortalizing oncogene . No cooperation was observed between EJ-H-ras(neo) and the unaltered v-myb oncogene .
|
[
0,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
1408144
|
Liver cancer , predominantly hepatocellular carcinoma ( HCC ) , represents a complex and fatal malignancy driven primarily by oxidative stress and inflammation . Due to dismal prognosis and limited therapeutic intervention , chemoprevention has emerged as a viable approach to reduce the morbidity and mortality of HCC . Pomegranate fruit is a rich source of phytochemicals endowed with potent antioxidant and anti-inflammatory properties . We previously reported that pomegranate phytochemicals inhibit diethylnitrosamine ( DENA)-initiated hepatocarcinogenesis in rats though nuclear factor E2-related factor 2 ( Nrf2)-mediated antioxidant mechanisms . Since Nrf2 also acts as a key mediator of the nuclear factor-kappaB ( NF-κB)-regulated inflammatory pathway , our present study investigated the anti-inflammatory mechanisms of a pomegranate emulsion ( PE ) during DENA-induced rat hepatocarcinogenesis . Rats were administered with PE ( 1 or 10 g/kg ) 4 weeks before and 18 weeks following DENA initiation . There was a significant increase in hepatic expressions of inducible nitric oxide synthase , 3-nitrotyrosine , heat shock protein 70 and 90 , cyclooxygenase-2 and NF-κB in DENA-exposed rat livers . PE dose-dependently suppressed all aforementioned elevated inflammatory markers . A conspicuous finding of this study involves lack of cardiotoxicity of PE as assessed by monitoring cardiac function using noninvasive echocardiography . Our results provide substantial evidence that suppression of the inflammatory cascade through modulation of NF-κB signaling pathway may represent a novel mechanism of liver tumor inhibitory effects of PE against experimental hepatocarcinogenesis . Data presented here coupled with those of our earlier study underline the importance of simultaneously targeting two interconnected molecular circuits , namely , Nrf2-mediated redox signaling and NF-κB-regulated inflammatory pathway , by pomegranate phytoconstituents to achieve chemoprevention of HCC .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
22841394
|
Proliferation of non-transformed cells is regulated by cell-cell contacts , which are referred to as contact-inhibition . Vice versa , transformed cells are characterised by a loss of contact-inhibition . Despite its generally accepted importance for cell-cycle control , little is known about the intracellular signalling pathways involved in contact-inhibition . Unravelling the molecular mechanisms of contact-inhibition and its loss during tumourigenesis will be an important step towards the identification of novel target genes in tumour diagnosis and treatment . To better understand the underlying molecular mechanisms we identified the transcriptional programme of contact-inhibition in NIH3T3 fibroblast using high-density microarrays . Setting the cut off : >or=1.5-fold , P <or= 0.05 , 853 genes and 73 cDNA sequences were differentially expressed in confluent compared to exponentially growing cultures . Importing these data into GenMAPP software revealed a comprehensive list of cell-cycle regulatory genes mediating G0/G1 arrest , which was confirmed by RT-PCR and Western blot . In a narrow analysis ( cut off : >or=2-fold , P <or= 0.002 ) , we found 110 transcripts to be differentially expressed representing 107 genes and 3 cDNA sequences involved , for example , in proliferation , signal transduction , transcriptional regulation , cell adhesion and communication . Interestingly , the majority of genes was upregulated indicating that contact-inhibition is not a passive state , but actively induced . Furthermore , we confirmed differential expression of eight genes by semi-quantitative RT-PCR and identified the potential tumour suppressor transforming growth factor-beta ( TGF-beta)-1-induced clone 22 ( TSC-22 ; tgfb1i4 ) as a novel protein to be induced in contact-inhibited cells .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
20564218
|
OBJECTIVE To investigate the expression and mutation of MTA1 , nm23H1 and E-cadherin(E-cad) genes in ovarian carcinoma ( OC ) in relation to lymph node ( LN ) metastasis . METHODS A panel of normal ovarian tissues , primary OC specimens and corresponding LNS was examined for mRNA expression and mutation of MTA1 and nm23H1 and protin expression of E-cad genes by using RT-PCR , RT-PCR-SSCP and immunohistochemistry . RESULTS The frequency of MTA1 over expression was 100%(7/7) in primary OC with metastasis but only 38.5%(5/13) in those without metastasis ( P = 0.0103 ) . Overexpression of MTA1 was observed in 87.5%(6/7) of LNS with metastasis but in only 23%(3/13) of LNS without metastasis ( P = 0.0118 ) . In contrast with MTA1 , low expression of nm23H1 mRNA was seen in 7 of 7 OC with metastasis but only in 4 of 13(30%) of those without metastasis ( P = 0.0043 ) . Low nm23H1 expression was also seen in 7 of 7 LNS with metastasis but only in 5 of 13 ( 38.5% ) nonmetastatic LNS ( P = 0.0102 ) . Meantime , no expression of E-cad protein was observed in 7 of 7 OC with metastasis but in 6 of 13(46.2%) of those without metastasis ( P = 0.044 ) . In correlation analysis of the three genes , MTA1 reversely correlated with nm23H1 and E-cad respectively ( r = -0.903 , -0.803 ) , and positive correlation existed between nm23H1 and E-cad ( r = 0.724 ) . No mutation of MTA1 , nm23H1 and was found by SSCP analysis . CONCLUSION The mRNA expression of MTA1 , nm23H1 and E-cad is positively and negatively correlated with LN metastasis . The expression abnormalities but not the mutations of the three genes are frequent events related to LN metastasis of ovarian cancer .
|
[
1,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
12599421
|
BACKGROUND AND AIMS : Impairment of the immune system may contribute to the risk for having cancer as Toll-like receptors are important for innate immunity . We examined the association between candidate disease-susceptibility polymorphisms in the single nucleotide polymorphism ( SNPs ) like TLR2 ( -196 to-174del ) , TLR3 ( C1377T ) , TLR4 ( Thr399Ile ) and TLR9 ( G2848A ) genes in patients with bladder cancer in a North Indian population . METHODS : SNPs were comprised of TLR2 ( -196 to -174 Del ) , TLR3(C1377T) , TLR4 ( Thr399Ile ) and TLR9 ( G2848A ) genes . Allelic and genotypic frequencies of these TLRs SNP from histopathologically confirmed patients of bladder cancer ( n=200 ) and unrelated healthy controls of similar ethnicity ( n=200 ) were genotyped by polymerase chain reaction restriction fragment length polymorphism ( PCR-RFLP ) analysis . RESULTS : In TLR2 I/D gene polymorphism , the combination of ID+DD showed a significant 3-fold increased risk ( p=0.001 ) . TLR2 with heterozygous genotype ID showed a 3-fold risk and combination of heterozygous and variant genotype ( ID+DD ) also showed a 5-fold risk with tumor stage/grade of patients with bladder cancer . The other genotypes of TLR3 , 4 and 9 did not exhibit any significant association with bladder cancer risk . CONCLUSIONS : Our results suggested the involvement of TLR2 ( -196 to-174 del ) in bladder cancer susceptibility ; however , TLR3 , 4 and 9 genes were not associated with risk of bladder cancer , implicating that polymorphisms in these tested TLRs genes are not likely to be associated with increased risk for developing bladder cancer . Functional studies in ethnically diverse populations may provide a more comprehensive involvement of innate immunity in identifying the disease-associated variants for the etiology of bladder cancer .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23142523
|
BACKGROUND To investigate the dynamics of inter- and intratumoral molecular alterations during tumor progression in recurrent gliomas . METHODOLOGY/PRINCIPAL FINDINGS To address intertumoral heterogeneity we investigated non-microdissected tumor tissue of 106 gliomas representing 51 recurrent tumors . To address intratumoral heterogeneity a set of 16 gliomas representing 7 tumor pairs with at least one recurrence , and 4 single mixed gliomas were investigated by microdissection of distinct oligodendroglial and astrocytic tumor components . All tumors and tumor components were analyzed for allelic loss of 1p/19q ( LOH 1p/19q ) , for TP53- mutations and for R132 mutations in the IDH1 gene . The investigation of non-microdissected tumor tissue revealed clonality in 75% ( 38/51 ) . Aberrant molecular alterations upon recurrence were detected in 25% ( 13/51). 64% ( 9/14 ) of these were novel and associated with tumor progression . Loss of previously detected alterations was observed in 36% ( 5/14 ) . One tumor pair ( 1/14 ; 7% ) was significant for both . Intratumoral clonality was detected in 57% ( 4/7 ) of the microdissected tumor pairs and in 75% ( 3/4 ) of single microdissected tumors. 43% ( 3/7 ) of tumor pairs and one single tumor ( 25% ) revealed intratumoral heterogeneity . While intratumoral heterogeneity affected both the TP53- mutational status and the LOH1p/19q status , all tumors with intratumoral heterogeneity shared the R132 IDH1- mutation as a common feature in both their microdissected components . CONCLUSIONS/SIGNIFICANCE The majority of recurrent gliomas are of monoclonal origin . However , the detection of divertive tumor cell clones in morphological distinct tumor components sharing IDH1- mutations as early event may provide insight into the tumorigenesis of true mixed gliomas .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22844452
|
Retinoic acid ( RA)-induced differentiation therapy is partially successful in neuroblastoma treatment . We found that a novel combination of vanadium-based PTP inhibitors with RA induced extensive differentiation in neuroblastoma cells . In contrast to RA alone , this led to either permanent differentiation or senescence after 14days of combined treatment followed by chemical removal . Senescence was dependent in part on synergistic AKT and ERK activation. p21 was also strongly induced , but in contrast to oncogene-induced senescence , p53 was not activated . Vanadium-based inhibitors thus serve strongly to enhance RA's ability to drive differentiation and a novel form of senescence in neuroblastoma cells .
|
[
0,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
23022267
|
A simple reversed-phase HPLC method for measuring hepatic levels of acetaminophen- ( APAP- ) protein adduct following an overdose of APAP was developed . An aliquot of liver homogenate in phosphate-buffered saline pH 7.4 ( PBS ) was placed on a Nanosep centrifugal device , which was centrifuged to obtain a protein residue . This residue was incubated with a solution of p-aminobenzoic acid ( PABA ) , the internal standard , and bacterial protease in PBS , transferred to a Nanosep centrifugal device , and centrifuged . A 100\u2009\u03bcL portion of the filtrate was analyzed on a YMC-Pack ODS-AMQ C18 column , using 100\u2009mM potassium dihydrogen phosphate-methanol-acetic acid ( 100\u2009:\u20090.6\u2009:\u20090.1 ) as the mobile phase , a flow rate of 1\u2009mL/min , and photometric detection at 254\u2009nm . PABA and APAP-cystein-S-yl ( APAP-Cys ) eluted at and 22.7\u2009min , respectively . Method linearity , based on on-column concentrations of APAP-Cys , was observed over the range 0.078-40\u2009\u03bcg . Recoveries of APAP-Cys from spiked blank liver homogenates ranged from to 91% . Limits of detection and of quantification of APAP-Cys , based on column concentrations , were 0.06\u2009\u03bcg and 0.14\u2009\u03bcg , respectively . RSD values for interday and intraday analyses of a blank liver homogenate spiked with APAP-Cyst at three levels were , in all cases , \u22641.0% and <1.5% , respectively . The proposed method was found appropriate for comparing the antidotal properties of N-acetylcysteine and taurine in a rat model of APAP poisoning .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22619591
|
There is little understanding of the factors controlling the mobilization of blast cells from bone marrow to peripheral blood and tissues . The aim of this study was to evaluate the soluble hepatocyte growth factor ( sHGF ) and vascular endothelial growth factor ( sVEGF ) levels in newly diagnosed patients with acute myeloid leukemia ( AML ) and to correlate these levels with the clinico-pathological features . Sixty-three patients with AML and 15 normal controls were included in this study . The levels of sHGF and sVEGF were determined by enzyme linked immunosorbent assay at diagnosis and after remission induction chemotherapy . Our results revealed significantly increased plasma levels of sHGF and sVEGF at diagnosis when compared to both control and remission levels ( P=0.000 for both ) . The sHGF and sVEGF levels differed between AML FAB subtypes ( P=0.000 ) . The highest concentrations were found in M5 followed by M4 . SHGF and sVEGF were directly correlated with peripheral white cell counts ( WBC ) ( r=0.836 , P=0.000 , r=0.718 ; P=0.000 , respectively ) , but inversely correlated with blast cell distribution ratio ( BCDR ) ( r=-0.785 , P=0.000 , r=-0.664 , P=0.000 , respectively ) . Moreover , both sHGF and sVEGF levels were significantly elevated in AML patients with extra-medullary infiltration as compared to those without ( P=0.000 , 0.006 , respectively ) . The sHGF but not sVEGF levels were significantly elevated in patients who died compared to those who relapsed and to patients in complete remission ( P=0.02 , 0.08 , respectively ) . Logistic regression analysis revealed that the sHGF level at diagnoses is a powerful predictor of the patient outcome , compared to sVEGF . In conclusion : our data support the hypothesis that angiogenic factors play a functional role in blast cell movement from the bone marrow to peripheral tissues . Assessment of sHGF at AML diagnosis is likely to be helpful in predicting patient outcome and selecting optimal therapeutic regimen .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
12850814
|
Investigations toward the understanding of chronic obstructive pulmonary disease ( COPD ) have been directed , so far , to the study of mechanisms leading to the disease . We believe that understanding why of smokers evade COPD and how this evasion is accomplished might be a fruitful endeavour that could advance knowledge of the development of the disease . Since the inflammatory infiltrate smokers develop seems to be the key element leading to the lung destruction in COPD , the understanding of the possible ways inflammation can be dampened , as well as its consequences , ought to be important . We review here some of the mechanisms by which inflammation is controlled : by the post-translational regulons , by the mechanisms preventing full activation of dendritic cells and by the regulatory T-cells . The potential role of the M2 alveolar macrophage phenotype and the newly described myeloid-derived suppressor cells is mentioned . We also point out that evasion comes at a price , as healthy smokers might be immunosuppressed to some extent and unable to prevent the development of cancer , certainly less so than in severe COPD , where immunity is heightened . Probably , the knowledge of the mechanisms of evasion from COPD could add significantly to the understanding of those leading to the disease .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22005915
|
High resolution oligonucleotide array Comparative Genome Hybridization technology ( array-CGH ) has greatly assisted the recognition of the 1p36 contiguous gene deletion syndrome . The 1p36 deletion syndrome is considered to be one of the most common subtelomeric microdeletion syndromes and has an incidence of in 5000 live births , while respectively the " pure " 1p36 microduplication has not been reported so far . We present seven new patients who were referred for genetic evaluation due to Developmental Delay ( DD ) , Mental Retardation ( MR ) , and distinct dysmorphic features . They all had a wide phenotypic spectrum . In all cases previous standard karyotypes were negative . Array-CGH analysis revealed five patients with interstitial 1p36 microdeletion ( four de novo and one maternal ) and two patients with de novo reciprocal duplication of different sizes . These were the first reported " pure " 1p36 microduplication cases so far . Three of our patients carrying the 1p36 microdeletion syndrome were also found to have additional pathogenetic aberrations . These findings ( del 3q27.1 ; del 4q21.22-q22.1 ; del 16p13.3 ; dup 21q21.2-q21.3 ; del Xp22.12 ) might contribute to the patients ' severe phenotype , acting as additional modifiers of their clinical manifestations . We review and compare the clinical and array-CGH findings of our patients to previously reported cases with the aim of clearly delineating more accurate genotype-phenotype correlations for the 1p36 syndrome that could allow for a more precise prognosis .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22766398
|
Insulin-like growth factor I ( IGF-I ) and IGF-II stimulate cancer cell proliferation via interaction with the type I IGF receptor ( IGF-IR ) . We put forward the hypothesis that IGF-IR mediates cancer cell growth by regulating amino acid transport , both when sufficient nutrients are present and when key nutrients such as glutamine are in limited supply . We examined the effects of alphaIR3 , the monoclonal antibody recognizing IGF-IR , on cell growth and amino acid transport across the cell membrane in a human neuroblastoma cell line , SK-N-SH . In the presence of alphaIR3 ( 2 micro/ml ) , cell proliferation was significantly attenuated in both control ( 2 mM glutamine ) and glutamine-deprived ( 0 mM glutamine ) groups . Glutamine deprivation resulted in significantly increased glutamate ( system X(AG)(-) ) , MeAIB ( system A ) , and leucine ( system L ) transport , which was blocked by alphaIR3 . Glutamine ( system ASC ) and MeAIB transport was significantly decreased by alphaIR3 in the control group . Addition of alphaIR3 significantly decreased DNA and protein biosynthesis in both groups . Glutamine deprivation increased the IGF-IR protein on the cell surface . Our results suggest that activation of IGF-IR promotes neuroblastoma cell proliferation by regulating trans-membrane amino acid transport .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
12031683
|
We have constructed plasmids pS3G-1 and pSG4 that contain single acetylaminofluorene adducts within contiguous runs of three ( 5'-CCCG1G2G3-3' ) and four ( 5'-CG1GGG4T-3' ) guanine residues , respectively . In Escherichia coli , the frequency of induced -1 frameshift mutations was strongly dependent on the position of modification : pS3G-G3 was approximately 100-fold and 10-fold more mutagenic than pS3G-G1 and pS3G-G2 , respectively ; pSG4-G4 was approximately 600-fold more mutagenic than pSG4-G1 . Mutagenesis was SOS-dependent and was markedly reduced in bacteria that were proficient in nucleotide excision repair as compared to a repair-deficient uvrA6 mutant . DNA sequencing showed that -1 frameshift events in pS3G-1 consisted of either targeted mutations ( greater than 90% of induced mutations ) within the guanine sequence or semitargeted mutations ( greater than 10% ) in the 5 ' flanking repetitive cytosine sequence . Semitargeted events , which were observed when acetylaminofluorene modification was at G1 and G2 , show that a lesion can reduce the fidelity of replication at positions 5 ' to its location on the template strand . No semitargeted frameshifts were observed in plasmid pSG4 , which lacks a repetitive sequence 5 ' to the adduct . Our results are consistent with a model for frameshift mutagenesis in which the acetylaminofluorene adduct ( i ) allows accurate incorporation of cytosine opposite the bulky lesion during DNA synthesis and ( ii ) impedes elongation of primer/template termini formed opposite the adduct or 5 ' to the adduct on the template strand , providing increased opportunity for the formation of slipped frameshift intermediates .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
1741385
|
Deregulation of insulin-like growth factor-1 receptor ( IGF-1R ) is closely associated with malignant transformation and tumor cell survival in various cancers . We found that IGF-1R expression level in leukemia cells positively correlated with the percentage of blast in bone marrow from de novo acute myeloid leukemia ( AML ) patients . Moreover , we showed that NVP-ADW742 , a novel small weight molecular inhibitor of IGF-IR , could induce apoptosis in both HL-60 cell line and primary AML blasts . However , no significant alteration of cell cycle was observed in HL-60 cells . Further studies revealed that NVP-ADW742 induced Akt dephosphorylation , which might subsequently induce p38 phosphorylation and decrease antiapoptotic protein Bcl-2 expression in HL-60 cells . Finally , we demonstrated that NVP-ADW742 could synergize with Ara-C to induce the kill in a subset of drug-resistant AML specimens . We suggested that IGF-lR targeting might be therapeutically beneficial for some AML patients .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
21141739
|
AMPK is a metabolic sensor that helps maintain cellular energy homeostasis . Despite evidence linking AMPK with tumor suppressor functions , the role of AMPK in tumorigenesis and tumor metabolism isunknown . Here we show that AMPK negatively regulates aerobic glycolysis ( the Warburg effect ) in cancer cells and suppresses tumor growth invivo . Genetic ablation of the \u03b11 catalytic subunit of AMPK accelerates Myc-induced lymphomagenesis . Inactivation of AMPK\u03b1 in both transformed and nontransformed cells promotes a metabolic shift to aerobic glycolysis , increased allocation of glucose carbon into lipids , and biomass accumulation . These metabolic effects require normoxic stabilization of the hypoxia-inducible factor-1\u03b1 ( HIF-1\u03b1 ) , as silencing HIF-1\u03b1 reverses the shift to aerobic glycolysis and the biosynthetic and proliferative advantages conferred by reduced AMPK\u03b1 signaling . Together our findings suggest that AMPK activity opposes tumor development and that its loss fosters tumor progression in part by regulating cellular metabolic pathways that support cell growth and proliferation .
|
[
0,
0,
1,
0,
0,
0,
0,
0,
0,
0
] |
23274086
|
Human CD93 , an epidermal growth factor ( EGF)-like domain containing transmembrane protein , is predominantly expressed in the vascular endothelium . Studies have shown that AA4 , the homolog of CD93 in mice , may mediate cell migration and angiogenesis in endothelial cells . Soluble CD93 has been detected in the plasma of healthy individuals . However , the role of soluble CD93 in the endothelium remains unclear . Recombinant soluble CD93 proteins with EGF-like domains ( rCD93D123 , with domains 1 , 2 , and 3 ; and rCD93D23 , with domains 2 and 3 ) were generated to determine their functions in angiogenesis . We found that rCD93D23 was more potent than rCD93D123 in stimulating the proliferation and migration of human umbilical vein endothelial cells ( HUVECs ) . Production of matrix-metalloproteinase 2 increased after the HUVECs were treated with rCD93D23 . Further , in a tube formation assay , rCD93D23 induced cell differentiation of HUVECs through phosphoinositide 3-kinase/Akt/endothelial nitric oxide synthase and extracellular signal-regulated kinases-1/2 signaling . Moreover , rCD93D23 promoted blood vessel formation in a Matrigel-plug assay and an oxygen-induced retinopathy model in vivo . Our findings suggest that the soluble EGF-like domain containing CD93 protein is a novel angiogenic factor acting on the endothelium .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
23272129
|
Polycylic aromatic hydrocarbons ( PAHs ) are ubiquitous contaminants in the marine environment . Their toxicity is mainly linked to the ability of marine species to biotransform them into reactive metabolites . PAHs are thus often detected at trace levels in animal tissues . For biomonitoring purposes , this findings have two main consequences , ( i ) the determination of the PAH tissue concentration is not suitable for the evaluation of individual exposure to PAHs ( ii ) it can explain sometimes the lack of correlations obtained with relevant markers of toxicity such as genotoxicity biomarkers . The aim of the present study was to better investigate the link between PAH exposure and genotoxicity in marine flatfish . During a laboratory experiment , juvenile soles were exposed for four weeks to a mixture of three PAHs , namely benzo[a]pyrene , fluoranthene and pyrene , followed by one week of depuration . Fish were exposed via the trophic route to a daily PAH concentration of 120 μg/g food . Fish were sampled at different time points . The bioavailability and the biotransformation of PAHs were assessed by the measurement of biliary metabolites using a sensitive UPLC MS/MS method . The 7-ethoxyresorufine-O-deethylase was also measured in liver subcellular fractions as a biomarker of phase I biotransformation activities . Genotoxicity was assessed in parallel by the measurement of DNA strand breaks in fish erythrocytes by the alkaline comet assay . During this study , the high amount of PAH metabolites produced in sole demonstrated the bioavailability of PAHs and their biotransformation by fish enzymes . A positive correlation was observed between the level of hydroxylated PAH metabolites and genotoxicity as measured by the alkaline comet assay .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20417553
|
We wanted to investigate the effects of gamma radiation on DNA single-strand breaks ( SSB ) and glutathione ( GSH ) levels in mononuclear blood cells ( MNC ) of radiotherapy technicians . DNA SSB in MNC of radiotherapy technicians who use ( 60)Co-gamma source in their works were detected by alkaline filter elution and compared to control subjects . In addition , GSH levels were measured using the enzymatic method in MNC . Blood samples were collected from radiotherapy technicians on Monday and Friday . DNA SSB levels were found to be significantly higher in smoking controls compared to non-smoking controls . Significant increases of 36% and 49% in DNA SSB were detected from Monday to Friday for non-smoking and smoking radiotherapy technicians , respectively . GSH levels were found to be decreased significantly from Monday to Friday . Gamma-radiation resulted in increased DNA SSB levels of MNC in radiotherapy technicians throughout the working week and these breaks have been observed to be repaired at the weekend . Smoking habit caused an additional increase in the SSBs observed in radiotherapy technicians .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
14578017
|
Dentin matrix protein 1 ( DMP1 ) is a member of the small integrin-binding ligand N-linked glycoprotein ( SIBLING ) family , a group of proteins initially described as mineralized extracellular matrices components . More recently , SIBLINGs have been implicated in several key steps of cancer progression , including angiogenesis . Although proangiogenic activities have been demonstrated for 2 SIBLINGs , the role of DMP1 in angiogenesis has not yet been addressed . We demonstrate that this extracellular matrix protein induced the expression of vascular endothelial cadherin ( VE-cadherin ) , a key regulator of intercellular junctions and contact inhibition of growth of endothelial cells that is also known to modulate vascular endothelial growth factor receptor 2 ( VEGFR-2 ) activity , the major high-affinity receptor for VEGF . DMP1 induced VE-cadherin and p27(Kip1) expression followed by cell-cycle arrest in human umbilical vein endothelial cells ( HUVECs ) in a CD44-dependent manner . VEGF-induced proliferation , migration , and tubulogenesis responses were specifically blocked on DMP1 pretreatment of HUVECs . Indeed , after VE-cadherin induction , DMP1 inhibited VEGFR-2 phosphorylation and Src-mediated signaling . However , DMP1 did not interfere with basic fibroblast growth factor-induced angiogenesis . In vivo , DMP1 significantly reduced laser-induced choroidal neovascularization lesions and tumor-associated angiogenesis . These data enable us to put DMP1 on the angiogenic chessboard for the first time and to identify this protein as a new specific inhibitor of VEGF-induced angiogenesis .
|
[
0,
0,
0,
0,
1,
0,
1,
0,
0,
0
] |
21190990
|
Cyclin-dependent kinases are most extensively studied targets for cancer chemotherapy since the tumor cells exhibit false checkpoints and can proliferate even if the genome is compromised . Cyclin-dependent kinases ensure the tight regulation of the cell cycle execution by mediating phosphorylation of cellular proteins . Deregulation of the cyclin-dependent kinase 2 activity by cellular and external factors leads to many diseases like cancers . Different methods like radiolabeled , fluorescence and luminescence are available for screening of library of compounds against kinases . However , bioluminescent methods offer several advantages like low background and no effect of fluorescent compound interference . Present study is focused on development , optimization and validation of cyclin-dependent kinase 2 assay which is suitable for identification potent and selective , ATP competitive and non-competitive inhibitors of cyclin-dependent kinase 2 . The aim of present investigation was to optimize the assay for cyclin-dependent kinase 2/cylin A and cyclin-dependent kinase 2/cyclin E with use of bioluminescence based biochemical reaction . Both cyclin-dependent kinase 2 which are cyclin-dependent kinase 2/cyclin A and cyclin-dependent kinase 2/cyclin E complexes , have different affinity for ATP . Therefore , both isoform analogs of cyclin-dependent kinase 2 were optimized separately . Optimum cyclin-dependent kinase 2/cyclin A and cyclin-dependent kinase 2/cyclin E concentration were found to be 250 ng/well and 200 ng/well , respectively . Optimum substrate ( histone H1 ) concentration was found to be 2.5 mg/ml for both cyclin-dependent kinase 2 analogs . Optimum reaction time was found to be 20 min for both cyclin-dependent kinase 2/cyclin complexes .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
21188035
|
It is prevailingly thought that the antiestrogens tamoxifen and ICI 182 , 780 are competitive antagonists of the estrogen-binding site of the estrogen receptor-alpha ( ER-α ) . However , a plethora of evidence demonstrated both antiestrogens exhibit agonist activities in different systems such as activation of the membrane-initiated signaling pathways . The mechanisms by which antiestrogens mediate estrogen-like activities have not been fully established . Previously , a variant of ER-α , EP-α36 , has been cloned and showed to mediate membrane-initiated estrogen and antiestrogen signaling in cells only expressing ER-α36 . Here , we investigated the molecular mechanisms underlying the antiestrogen signaling in ER-negative breast cancer MDA-MB-231 and MDA-MB-436 cells that express high levels of endogenous ER-α36 . We found that the effects of both 4-hydoxytamoxifen ( 4-OHT ) and ICI 182 , 780 ( ICI ) exhibited a non-monotonic , or biphasic dose response curve ; antiestrogens at low concentrations , elicited a mitogenic signaling pathway to stimulate cell proliferation while at high concentrations , antiestrogens inhibited cell growth . Antiestrogens at l nM induced the phosphorylation of the Src-Y416 residue , an event to activate Src , while at 5 �M induced Src-Y527 phosphorylation that inactivates Src . Antiestrogens at 1 nM also induced phosphorylation of the MAPK/ERK and activated the Cyclin D1 promoter activity through the Src/EGFR/STAT5 pathways but not at 5 �M . Knock-down of ER-α36 abrogated the biphasic antiestrogen signaling in these cells . Our results thus indicated that ER-α36 mediates biphasic antiestrogen signaling in the ER-negative breast cancer cells and Src functions as a switch of antiestrogen signaling dependent on concentrations of antiestrogens through the EGFR/STAT5 pathway .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
22276155
|
Ulcerative colitis ( UC ) is a major form of chronic inflammation that can frequently progress to colon cancer . Several studies have demonstrated massive infiltration of neutrophils and macrophages into the lamina propria and submucosa in the progression of UC-associated colon carcinogenesis . Macrophages contribute to the development of colitis-associated colon cancer ( CAC ) . However , the role of neutrophils is not well understood . To better understand the involvement of tumor-associated neutrophils ( TANs ) in the regulation of CAC , we used a mouse CAC model produced by administering azoxymethane ( AOM ) , followed by repeated dextran sulfate sodium ( DSS ) ingestion . This causes severe colonic inflammation and subsequent development of multiple tumors in mice colon . We observed that colorectal mucosal inflammation became increasingly severe with AOM and DSS treatment . Macrophages infiltrated the lamina propria and submucosa , together with a marked increase in neutrophil infiltration . The chemokine CXCL2 increased in the lamina propria and submucosal regions of the colons of the treated mice , together with the infiltration of neutrophils expressing CXCR2 , a specific receptor for CXCL2 . This process was followed by neoplastic transformation . After AOM and DSS treatment , the mice showed enhanced production of metalloproteinase ( MMP)-9 and neutrophil elastase ( NE ) , accompanied by excessive vessel generation and cell proliferation . Moreover , CXCL2 promoted neutrophil recruitment and induced neutrophils to express MMP-9 and NE in vitro . Furthermore , administration of neutrophil-neutralizing antibodies after the last DSS cycle markedly reduced the number and size of tumors and decreased the expression of CXCR2 , CXCL2 , MMP-9 , and NE . These observations indicate a crucial role for TANs in the initiation and progression of CAC and suggest that the CXCL2-CXCR2 axis might be useful in reducing the risk of UC-associated colon cancer .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
1
] |
23272179
|
Cancer cells constantly adapt to oxidative phosphorylation ( OXPHOS ) suppression resulting from hypoxia or mitochondria defects . Under the OXPHOS suppression , AMP-activated protein kinase ( AMPK ) regulates global metabolism adjustments , but its activation has been found to be transient . Whether cells can maintain cellular ATP homeostasis and survive beyond the transient AMPK activation is not known . Here , we study the bioenergetic adaptation to the OXPHOS inhibitor oligomycin in a group of cancer cells . We found that oligomycin at 100 ng/ml completely inhibits OXPHOS activity in 1 h and induces various levels of glycolysis gains by 6 h , from which we calculate the bioenergetic organizations of cancer cells . In glycolysis-dominant cells , oligomycin does not induce much energy stress as measured by glycolysis acceleration , ATP imbalance , AMPK activation , AMPK substrate acetyl-CoA carboxylase phosphorylation at Ser(79) , and cell growth inhibition . In OXPHOS-dependent LKB1 wild type cells , oligomycin induces 5-8% ATP drops and transient AMPK activation during the initial 1-2 h . After AMPK activation is completed , oligomycin-induced increase of acetyl-CoA carboxylase phosphorylation at Ser(79) is still detected , and cellular ATP is back at preoligomycin treatment levels by sustained elevation of glycolysis . Cell growth , however , is inhibited without an increase in cell death and alteration in cell cycle distribution . In OXPHOS-dependent LKB1-null cells , no AMPK activation by oligomycin is detected , yet cells still show a similar adaptation . We also demonstrate that the adaptation to oligomycin does not invoke activation of hypoxia-induced factor . Our data suggest that cancer cells may grow and survive persistent OXPHOS suppression through an as yet unidentified regulatory mechanism .
|
[
0,
0,
1,
0,
0,
0,
0,
0,
0,
0
] |
20110356
|
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