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Aurora kinases play an essential role in mitotic progression and are potentially druggable targets in cancer therapy . We identified benzo[e]pyridoindoles ( BePI ) as powerful aurora kinase inhibitors . Their efficiency was demonstrated both in enzymatic inhibition studies and in cell culture assays . New BePI molecules were synthesized , and a structure-activity relationship study was conducted with the aim of improving the activity and solubility of the lead compound . Tetracyclic BePI derivatives are characterized by a particular curved shape , and the presence of an oxo group on the pyridine ring was found to be required for aurora kinase B inhibition . New hydrosoluble benzo[e]pyridoindolones were subsequently designed , and their efficacy was tested by a combination of cell-cycle analysis and time-lapse experiments in live cells . The most active BePI derivative , 13 b , inhibited the cell cycle , drove cells to polyploidy , and eventually induced apoptosis . It exhibited high antiproliferative activity in HeLa cells with an IC(50) value of 63 nM . Relative to compounds tested in clinical trials , this antiproliferative potency places 13 b among the top 10 aurora kinase inhibitors . Our results justify further in vivo evaluation in preclinical animal models of cancer .
|
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23281044
|
Transforming growth factor beta ( TGF-β ) signaling has been implicated in driving tumor progression and metastasis by inducing stem cell-like features in some human cancer cell lines . In this study , we have utilized a novel murine cell line NMuMG-ST , which acquired cancer stem cell ( CSC ) phenotypes during spontaneous transformation of the untransformed murine mammary cell line NMuMG , to investigate the role of autocrine TGF-β signaling in regulating their survival , metastatic ability , and the maintenance of cancer stem cell characteristics . We have retrovirally transduced a dominant-negative TGF-β type II receptor ( DNRII ) into the NMuMG-ST cell to abrogate autocrine TGF-β signaling . The expression of DNRII reduced TGF-β sensitivity of the NMuMG-ST cells in various cell-based assays . The blockade of autocrine TGF-β signaling reduced the ability of the cell to grow anchorage-independently and to resist serum deprivation-induced apoptosis . These phenotypes were associated with reduced levels of active and phosphorylated AKT and ERK , and Gli1 expression suggesting that these pathways contribute to the growth and survival of this model system . More interestingly , the abrogation of autocrine TGF-β signaling also led to the attenuation of several features associated with mammary stem cells including epithelial-mesenchymal transition , mammosphere formation , and expression of stem cell markers . When xenografted in athymic nude mice , the DNRII cells were also found to undergo apoptosis and induced significantly lower lung metastasis burden than the control cells even though they formed similar size of xenograft tumors . Thus , our results indicate that autocrine TGF-β signaling is involved in the maintenance and survival of stem-like cell population resulting in the enhanced metastatic ability of the murine breast cancer cells .
|
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23482850
|
Induced pluripotent stem ( iPS ) cells share some basic properties , such as self-renewal and pluripotency , with cancer cells , and they also appear to share several metabolic alterations that are commonly observed in human tumors . The cancer cells ' glycolytic phenotype , first reported by Otto Warburg , is necessary for the optimal routing of somatic cells to pluripotency . However , how iPS cells establish a Warburg-like metabolic phenotype and whether the metabolic pathways that support the bioenergetics of iPS cells are produced by the same mechanisms that are selected during the tumorigenic process remain largely unexplored . We recently investigated whether the reprogramming-competent metabotype of iPS cells involves changes in the activation/expression status of the H ( + ) -ATPase , which is a core component of mitochondrial oxidative phosphorylation that is repressed at both the activity and protein levels in human carcinomas , and of the lipogenic switch , which refers to a marked overexpression and hyperactivity of the acetyl-CoA carboxylase ( ACACA ) and fatty acid synthase ( FASN ) lipogenic enzymes that has been observed in nearly all examined cancer types . A comparison of a starting population of mouse embryonic fibroblasts and their iPS cell progeny revealed that somatic cell reprogramming involves a significant increase in the expression of ATPase inhibitor factor 1 ( IF1 ) , accompanied by extremely low expression levels of the catalytic β-F1-ATPase subunit . The pharmacological inhibition of ACACA and FASN activities markedly decreases reprogramming efficiency , and ACACA and FASN expression are notably upregulated in iPS cells . Importantly , iPS cells exhibited a significant intracellular accumulation of neutral lipid bodies ; however , these bodies may be a reflection of intense lysosomal/autophagocytic activity rather than bona fide lipid droplet formation in iPS cells , as they were largely unresponsive to pharmacological modulation of PPARgamma and FASN activities . The AMPK agonist metformin , which endows somatic cells with a bioenergetic infrastructure that is protected against reprogramming , was found to drastically elongate fibroblast mitochondria , fully reverse the high IF1/β-F1-ATPase ratio and downregulate the ACACA/FASN lipogenic enzymes in iPS cells . The mitochondrial H ( + ) -ATP synthase and the ACACA/FASN-driven lipogenic switch are newly characterized as instrumental metabolic events that , by coupling the Warburg effect to anabolic metabolism , enable de-differentiation during the reprogramming of somatic cells to iPS cells .
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23287468
|
Lung cancers express the cholinergic autocrine loop , which facilitates the progression of cancer cells . The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers ( SCLCs ) . In this study we intended to investigate the growth inhibitory effect of R2HBJJ , a novel muscarinic antagonist , on non-small cell lung cancer ( NSCLC ) cells and the possible mechanisms . The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs . R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea . R2HBJJ markedly suppressed the growth of NSCLC cells , such as H1299 , H460 and H157 . In H1299 cells , both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin . Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition . Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection , respectively . Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb . Therefore , the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells . R2HBJJ , as a novel mAChRs antagonist , can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth , which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC .
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23285263
|
Contradictory results have been reported regarding the association between vascularity ( used as an index of angiogenesis ) and thrombospondin-1 ( TSP-1 ) in human tumours . In previous studies , the reported association was based on the estimated average TSP-1 value per tumour , with a sufficient number of specimens collectively analysed per tumour type . Given the extent of intra-tumour heterogeneity , we determined the association between TSP-1 and vascularity within individual specimens , based on the average values of TSP-1 and vascularity in 10-20 pre-selected areas per tumour . Cells expressing TSP-1 mRNA were visualised by in situ hybridisation and quantified by point counting . Vascularity was quantified by point counting and vessel density of von Willebrand Factor-positive vessels . In 10 ductal breast carcinomas , a direct correlation between TSP-1 and vascularity was found in 4 tumours , no correlation in 3 and an inverse correlation in 3 . The effect of TSP-1 on endothelial cell migration in vitro was assessed in the Boyden chamber assay . TSP-1 stimulated cell migration at low concentrations ( 0.1-10 microg/ml ) and was inhibitory at high concentrations ( 25-100 microg/ml ) . These results suggest that TSP-1 may elicit a concentration-dependent , bi-phasic , effect on angiogenesis .
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12814189
|
The NF-kB family of transcription factors regulates important biological functions including cell growth , survival and the immune response . We found that Human Papillomavirus type 16 ( HPV-16 ) E7 and E6/E7 proteins inhibited basal and TNF-alpha-inducible NF-kB activity in human epithelial cells cultured from the cervical transformation zone , the anatomic region where most cervical cancers develop . In contrast , HPV-16 E6 regulated NF-kB in a cell type- and cell growth-dependent manner . NF-kB influenced immortalization of cervical cells by HPV16 . Inhibition of NF-kB by an IkB alpha repressor mutant increased colony formation and immortalization by HPV-16 . In contrast , activation of NF-kB by constitutive expression of p65 inhibited proliferation and immortalization . Our results suggest that inhibition of NF-kB by HPV-16 E6/E7 contributes to immortalization of cells from the cervical transformation zone .
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22284893
|
Olfactomedin 4 ( OLFM4 ) is highly expressed in gastrointestinal cancers and has an anti-apoptotic function . The roles of OLFM4 in tumor growth and metastasis and how it functions in these processes remain elusive . We investigated the function of OLFM4 in tumor growth and metastasis using B16F10 mouse melanoma cells as an experimental system . Our results showed that OLFM4 had no positive effect on cell viability or cell cycle progression in B16F10 cells . However , it significantly suppressed the tumorigenicity of B16F10 cells , i.e. , intradermal primary tumor growth and lung metastasis . OLFM4 also suppressed the migration and invasion of B16F10 cells in vitro . For further insight into the mechanisms underlying OLFM4-mediated suppression of tumor progression , we examined the effect of OLFM4 on the expression of integrin and matrix metalloproteinase ( MMP ) , both of which are involved in tumor progression . Overexpression of OLFM4 clearly reduced the expression levels of integrin α1 , integrin α4 , integrin α5 , integrin α6 , and MMP9 . Moreover , forced expression of MMP9 attenuated the inhibitory activity of OLFM4 on migration and invasiveness . Our findings provide the experimental evidence that OLFM4 may function as a tumor suppressor and an anti-metastatic gene during tumor progression .
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23161172
|
Contrary to the paradigm that cancer incidence increases indefinitely with age , significant data now suggest cancer incidence may markedly reduce beyond age 80 years for humans and beyond 800 days for mice , and is not inevitable . We show that increasing cellular senescence with age is a possible cause of this reduction , since senescent cells are removed from the pool of cells that retain proliferative ability necessary for cancer . We further show that animal interventions appearing to alter senescence , p53 mutation and melatonin dosing , support the prediction that increasing senescence rate reduces cancer while reducing lifespan , and vice versa . Studies of environmental agents associated with increased cancer might be re-examined to find if there is an association with longevity increases , which may markedly alter our view of such agents . We also show that if an agent functions by slowing both senescence and carcinogenesis , longevity is increased while reducing cancer . Dietary restriction is the only known intervention that accomplishes this , but there may be others .
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15119525
|
Surgery is the most effective therapy for cancer in the United States , but disease still recurs in more than 40% of patients within 5 years after resection . Chemotherapy is given postoperatively to prevent relapses ; however , this approach has had marginal success . After surgery , recurrent tumors depend on rapid neovascular proliferation to deliver nutrients and oxygen . Phosphatidylserine ( PS ) is exposed on the vascular endothelial cells in the tumor microenvironment but is notably absent on blood vessels in normal tissues . Thus , PS is an attractive target for cancer therapy after surgery . Syngeneic mice bearing TC1 lung cancer tumors were treated with mch1N11 ( a novel mouse chimeric monoclonal antibody that targets PS ) , cisplatin ( cis ) , or combination after surgery . Tumor relapses and disease progression were decreased 90% by combination therapy compared with a 50% response rate for cis alone ( P = .02 ) . Mice receiving postoperative mch1N11 had no wound-related complications or added systemic toxicity in comparison to control animals . Mechanistic studies demonstrated that the effects of mch1N11 were associated with a dense infiltration of inflammatory cells , particularly granulocytes . This strategy was independent of the adaptive immune system . Together , these data suggest that vascular-targeted strategies directed against exposed PS may be a powerful adjunct to postoperative chemotherapy in preventing relapses after cancer surgery .
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22577350
|
Oral squamous cell carcinoma ( OSCC ) is the most common malignant tumor in the oral and maxillofacial region . The mechanism of carcinogenesis of OSCC is still unclear . Based on the previous cell line , HIOEC-B(a)P-96 ( HB96 ) , which we obtained by HPV16 E6/E7-immortalized human oral epithelial cells ( HIOEC ) and benzo(a)pyrene inducement , we prepared a new HB-second generation cancer cell line ( HB-2 ) by continuous passage . Its characteristics such as morphology , proliferation activity , karyotype , and tumorigenesis were studied . The HB-2 cells displayed uncontrolled cell division and lost contact inhibition leading to cell overlap . Cells were polygonal and unevenly shaped , with an increased nucleus versus plasma ratio . Increased proliferative activity was confirmed by MTT assays . The tumorigenicity was confirmed by tumor growth experiments in nude mice . Therefore , the HB-2 and HB96 cell lines are useful tools to study the mechanism of carcinogenesis of OSCC in vitro for future genomic and proteomic analyses .
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20464641
|
INTRODUCTION Tamoxifen is the most widely prescribed anti-estrogen treatment for patients with estrogen receptor ( ER)-positive breast cancer . However , there is still a need for biomarkers that reliably predict endocrine sensitivity in breast cancers and these may well be expressed in a dynamic manner . METHODS In this study we assessed gene expression changes at multiple time points ( days 1 , 2 , 4 , 7 , 14 ) after tamoxifen treatment in the ER-positive ZR-75-1 xenograft model that displays significant changes in apoptosis , proliferation and angiogenesis within 2 days of therapy . RESULTS Hierarchical clustering identified six time-related gene expression patterns , which separated into three groups : two with early/transient responses , two with continuous/late responses and two with variable response patterns . The early/transient response represented reductions in many genes that are involved in cell cycle and proliferation ( e.g . BUB1B , CCNA2 , CDKN3 , MKI67 , UBE2C ) , whereas the continuous/late changed genes represented the more classical estrogen response genes ( e.g . TFF1 , TFF3 , IGFBP5 ) . Genes and the proteins they encode were confirmed to have similar temporal patterns of expression in vitro and in vivo and correlated with reduction in tumour volume in primary breast cancer . The profiles of genes that were most differentially expressed on days 2 , 4 and 7 following treatment were able to predict prognosis , whereas those most changed on days 1 and 14 were not , in four tamoxifen treated datasets representing a total of 404 patients . CONCLUSIONS Both early/transient/proliferation response genes and continuous/late/estrogen-response genes are able to predict prognosis of primary breast tumours in a dynamic manner . Temporal expression of therapy-response genes is clearly an important factor in characterising the response to endocrine therapy in breast tumours which has significant implications for the timing of biopsies in neoadjuvant biomarker studies .
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20569502
|
Malignant peripheral nerve sheath tumors ( MPNSTs ) are sarcomas able to grow under conditions of metabolic stress caused by insufficient nutrients or oxygen . Both pituitary adenylate cyclase-activating polypeptide ( PACAP ) and activity-dependent neuroprotective protein ( ADNP ) have glioprotective potential . However , whether PACAP/ADNP signaling is involved in the resistance to cell death in MPNST cells remains to be clarified . Here , we investigated the involvement of this signaling system in the survival response of MPNST cells against hydrogen peroxide ( H(2)O(2))-evoked death both in the presence of normal serum ( NS ) and in serum-starved ( SS ) cells . Results showed that ADNP levels increased time-dependently ( 6-48 h ) in SS cells . Treatment with PACAP38 ( 10(-9) to 10(-5) M ) dose-dependently increased ADNP levels in NS but not in SS cells . PAC(1)/VPAC receptor antagonists completely suppressed PACAP-stimulated ADNP increase and partially reduced ADNP expression in SS cells . NS-cultured cells exposed to H(2)O(2) showed significantly reduced cell viability ( % ) , increased p53 and caspase-3 , and DNA fragmentation , without affecting ADNP expression . Serum starvation significantly reduced H(2)O(2)-induced detrimental effects in MPNST cells , which were not further ameliorated by PACAP38 . Altogether , these finding provide evidence for the involvement of an endogenous PACAP-mediated ADNP signaling system that increases MPNST cell resistance to H(2)O(2)-induced death upon serum starvation .
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22454142
|
PTEN , a phosphoinositide-3-phosphatase , serves dual roles as a tumor suppressor and regulator of cellular anabolic/catabolic metabolism . Adaptation of a redox-sensitive cysteinyl thiol in PTEN for signal transduction by hydrogen peroxide may have superimposed a vulnerability to other mediators of oxidative stress and inflammation , especially reactive carbonyl species , which are commonly occurring by-products of arachidonic acid peroxidation . Using MCF7 and HEK-293 cells , we report that several reactive aldehydes and ketones , e.g. electrophilic α,β-enals ( acrolein , 4-hydroxy-2-nonenal ) and α,β-enones ( prostaglandin A(2) , Δ12-prostaglandin J(2) and 15-deoxy-Δ-12,14-prostaglandin J(2) ) covalently modify and inactivate cellular PTEN , with ensuing activation of PKB/Akt kinase ; phosphorylation of Akt substrates ; increased cell proliferation ; and increased nuclear β-catenin signaling . Alkylation of PTEN by α,β-enals/enones and interference with its restraint of cellular PKB/Akt signaling may accentuate hyperplastic and neoplastic disorders associated with chronic inflammation , oxidative stress , or aging .
|
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1
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20975834
|
Previously , stereoselective hydroxylation of \u03b1-ionone by Cytochrome P450 BM3 mutants M01 A82W and M11 L437N was observed . While both mutants hydroxylate \u03b1-ionone in a regioselective manner at the C3 position , M01 A82W catalyzes formation of trans-3-OH-\u03b1-ionone products whereas M11 L437N exhibits opposite stereoselectivity , producing trans-(3S,6S)-OH-\u03b1-ionone and cis-(3S,6R)-OH-\u03b1-ionone . Here , we explore the stereoselective C3 hydroxylation of \u03b1-ionone by Cytochrome P450 BM3 mutants M01 A82W and M11 L437N using molecular dynamics-based free energy calculations to study the interaction between the enzyme and both the substrates and the products . The one-step perturbation approach is applied using an optimized reference state for substrates and products . While the free energy differences between the substrates free in solution amount to kJ mol(-1) , the differences in mutant M01 A82W agree with the experimentally obtained dissociation constants K(d) . Moreover , a correlation with experimentally observed trends in product formation is found in both mutants . The trans isomers show the most favorable relative binding free energy in the range of all four possible hydroxylated diastereomers for mutant M01 A82W , while the trans product from ( 6S)-\u03b1-ionone and the cis product from ( 6R)-\u03b1-ionone show highest affinity for mutant M11 L437N . Marcus theory is subsequently used to relate the thermodynamic stability to transition state energies and rates of formation .
|
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22765880
|
Reciprocity of inflammation , oxidative stress and neovascularization is emerging as an important mechanism underlying numerous processes from tissue healing and remodelling to cancer progression . Whereas the mechanism of hypoxia-driven angiogenesis is well understood , the link between inflammation-induced oxidation and de novo blood vessel growth remains obscure . Here we show that the end products of lipid oxidation , ω-(2-carboxyethyl)pyrrole ( CEP ) and other related pyrroles , are generated during inflammation and wound healing and accumulate at high levels in ageing tissues in mice and in highly vascularized tumours in both murine and human melanoma . The molecular patterns of carboxyalkylpyrroles are recognized by Toll-like receptor 2 ( TLR2 ) , but not TLR4 or scavenger receptors on endothelial cells , leading to an angiogenic response that is independent of vascular endothelial growth factor . CEP promoted angiogenesis in hindlimb ischaemia and wound healing models through MyD88-dependent TLR2 signalling . Neutralization of endogenous carboxyalkylpyrroles impaired wound healing and tissue revascularization and diminished tumour angiogenesis . Both TLR2 and MyD88 are required for CEP-induced stimulation of Rac1 and endothelial migration . Taken together , these findings establish a new function of TLR2 as a sensor of oxidation-associated molecular patterns , providing a key link connecting inflammation , oxidative stress , innate immunity and angiogenesis .
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20927103
|
UNLABELLED BACKGROUND Cell lines are very useful for clinical and basic research . Thus far , only 11 reports have documented the characteristics of ovarian endometrioid adenocarcinoma cell lines in the literature . Due to the scarcity of information , the establishment of an ovarian malignant tumor cell line with distinctive characteristics is particularly important to study this disease . Thus , this study was undertaken to establish and characterize a new human endometrioid adenocarcinoma cell line of the ovary . METHODS The cell line NOMH-1 was established from an ovarian tumor of a 44-year-old woman . Features of the cell line studied included morphology , chromosome analysis , heterotransplantation , tumor markers , and chemosensitivity . RESULTS This cell line has been growing well for 232 months and subcultured more than 50 times . Monolayer cultured cells were polygonal in shape , showing a pavement-like arrangement and a tendency to stack without contact inhibition . They exhibited a human karyotype with a modal chromosomal number in the hypertriploid range . The cells could be transplanted into the subcutis of nude mice and produced tumors resembling the original tumor . NOMH-1 cells expressed both CEA and CA19-9 which were identified immunohistochemically in the original tumor and the heterotransplanted tumor . The cells were sensitive to paclitaxel , an agent commonly used in the treatment of gynecological cancers . CONCLUSIONS NOMH-1 is the first ovarian endometrioid adenocarcinoma cell line in which CEA and CA19-9 expression have been defined . This newly established cell line should be useful for investigating the characteristics of ovarian endometrioid adenocarcinoma .
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23379414
|
OBJECTIVE To study the effects of genistein on the proliferation , apoptosis induction and expression of related gene proteins of human colon cancer cells in vitro and in vivo , and its mechanisms of action . METHODS MTT colorimetric assay was used to detect the effects of genistein on the proliferation of human colon adenocarcinoma SW480 cells . Light and transmission electron microscopy were used to study the histological and ultrastructural changes . Flow cytometry was used to determine the effects of genistein on cell cycle and apoptosis . Flow cytometry and immunohistochemistry were used to determine the effects of genistein on apoptosis induction and expression of related gene proteins of colon cancer cells . RESULTS The MTT colorimetric assay showed that genistein inhibited the proliferation of SW480 cells in a dose-dependent and time-dependent manner , and the highest inhibition rate was 60.2% after 80 microg/ml genistein treatment for 72 h . The light microscopy revealed that many genistein-treated cancer cells were shrunken , disrupted , or showing cytoplasmic vacuolization . The electron microscopic examination showed cell shrinkage , nuclear fragmentation and pronounced chromatin condensation , sometimes formed crescent chromatin condensation attached to the nuclear membrane . The results of flow cytometry showed that : after SW480 cells were treated with 0 , 20 , 40 , 80 microg/ml genistein for 48 h , the FI values of PCNA were 1.49 +/- 0.02 , 1.28 +/- 0.04 , 1.14 +/- 0.03 , and 0.93 +/- 0.08 ; the FI values of VEGF were 1.75 +/- 0.02 , 1.34 +/- 0.06 , 1.32 +/- 0.04 , and 1.23 +/- 0.04 ; the fluorescence index ( FI ) values of p21 were 1.26 +/- 0.05 , 1.36 +/- 0.06 , 1.61 +/- 0.03 , and 1.73 +/- 0.03 , respectively . There were statistically significant differences between the control group and each treatment group ( P < 0.05 or P < 0.01 ) . The scores of immunohistochemical staining of PCNA and VEGF proteins were decreased , while p21 increased . There were statistically significant differences between the control group and each treatment group ( P < 0.05 or P < 0.01 ) . CONCLUSION Genistein can inhibit the growth of colon cancer cells via apoptosis induction and cell cycle arrest at G(2)/M phase . The anti-tumor mechanisms of genistein may be related with the down-regulation of expression of VEGF and PCNA , and up-regulation of the expression of p21 .
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20211058
|
We have developed fluorescent probes for the detection of strand scission in the excision repair of oxidatively damaged bases . They were hairpin-shaped oligonucleotides , each containing an isomer of thymine glycol or 5,6-dihydrothymine as a damaged base in the center , with a fluorophore and a quencher at the 5'- and 3'-ends , respectively . Fluorescence was detected when the phosphodiester linkage at the damage site was cleaved by the enzyme , because the short fragment bearing the fluorophore could not remain in a duplex form hybridized to the rest of the molecule at the incubation temperature . The substrate specificities of Escherichia coli endonuclease III and its human homolog , NTH1 , determined by using these probes agreed with those determined previously by gel electrophoresis using ( 32)P-labeled substrates . Kinetic parameters have also been determined by this method . Since different fluorophores were attached to the oligonucleotides containing each lesion , reactions with two types of substrates were analyzed separately in a single tube , by changing the excitation and detection wavelengths . These probes were degraded during an incubation with a cell extract . Therefore , phosphorothioate linkages were incorporated to protect the probes from nonspecific nucleases , and the base excision repair activity was successfully detected in HeLa cells .
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20110254
|
Molecular mechanisms involved in progression of clear-cell renal-cell carcinomas ( ccRCCs ) are poorly understood . A common genetic mutation found in ccRCC is the loss of the von Hippel-Lindau ( VHL ) gene , which contributes to cancer progression and metastasis . We investigated VIP effects on metastatic and angiogenic factors in human VHL-null A498 ccRCC and HK2 renal cells . VIP increased adhesion but decreased expression of metalloproteinases , MMP2 and MMP9 , as well as cell migration and VEGF expression and secretion in A498 but not in HK2 cells . VIP enhanced ROS levels and decreased nuclear levels of β-catenin and NFκB p50-subunit in A498 cells , suggesting neuropeptide involvement in the observed decrease of metastatic ability in clear-cell carcinoma . VIP effects in A498 cells were blocked by the VPAC(1/2)-receptor antagonist JV-1-53 . In conclusion , present data point to a role of VIP in preventing invasion and metastasis in ccRCCs and support its potential therapeutic usefulness in this disease .
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1,
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23123564
|
Lanthanide(III) complexes [ Ln(pyphen)(acac)(2)(NO(3)) ] ( 1 , 2 ) , [ Ln(pydppz)(acac)(2)(NO(3)) ] ( 3 , 4 ) and [ La(pydppz)(anacac)(2)(NO(3)) ] ( 5 ) , where Ln is La(III) ( in 1 , 3 , 5 ) and Gd(III) ( in 2 , 4 ) , pyphen is 6-(2-pyridyl)-1,10-phenanthroline , pydppz is 6-(2-pyridyl)-dipyrido[3,2-a:2',3'-c]phenazine , anacac is anthracenylacetylacetonate and acac is acetylacetonate , were prepared , characterized and their DNA photocleavage activity and photocytotoxicity studied . The crystal structure of complex 2 displays a GdO(6)N(3) coordination . The pydppz complexes 3-5 show an electronic spectral band at nm in DMF . The La(III) complexes are diamagnetic , while the Gd(III) complexes are paramagnetic with seven unpaired electrons . The molar conductivity data suggest 1 : 1 electrolytic nature of the complexes in aqueous DMF . They are avid binders to calf thymus DNA giving K(b) in the range of 5.4 � 10(4)-1.2 � 10(6) M(-1) . Complexes 3-5 efficiently cleave supercoiled DNA to its nicked circular form in UV-A light of 365 nm via formation of singlet oxygen ( (1)O(2) ) and hydroxyl radical ( HO˙ ) species . Complexes 3-5 also exhibit significant photocytotoxic effect in HeLa cancer cells giving respective IC(50) value of 0.16(�0.01) , 0.15(�0.01) and 0.26�(0.02) μM in UV-A light of 365 nm , while they are less toxic in dark with an IC(50) value of >3 μM . The presence of an additional pyridyl group makes the pydppz complexes more photocytotoxic than their dppz analogues . FACS analysis of the HeLa cells treated with complex 4 shows apoptosis as the major pathway of cell death . Nuclear localization of complex 5 having an anthracenyl moiety as a fluorophore is evidenced from the confocal microscopic studies .
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22086203
|
In recent years , microfluidic systems have been used to study fundamental aspects of angiogenesis through the patterning of single-layered , linear or geometric vascular channels . In vivo , however , capillaries exist in complex , three-dimensional ( 3D ) networks , and angiogenic sprouting occurs with a degree of unpredictability in all x,y,z planes . The ability to generate capillary beds in vitro that can support thick , biological tissues remains a key challenge to the regeneration of vital organs . Here , we report the engineering of 3D capillary beds in an in vitro microfluidic platform that is comprised of a biocompatible collagen I gel supported by a mechanical framework of alginate beads . The engineered vessels have patent lumens , form robust mm capillary networks across the devices , and support the perfusion of 1 �m fluorescent beads through them . In addition , the alginate beads offer a modular method to encapsulate and co-culture cells that either promote angiogenesis or require perfusion for cell viability in engineered tissue constructs . This laboratory-constructed vascular supply may be clinically significant for the engineering of capillary beds and higher order biological tissues in a scalable and modular manner .
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23226527
|
Osteopetrosis , a disorder of skeletal bone , can cause death during childhood . We previously described a new spontaneous autosomal recessive osteopetrosis mouse mutant , " new toothless " ( ntl ) . In this study , we reported for the first time the identification , cloning and characterization of the coiled-coil domain-containing 154 ( CCDC154 ) , a novel gene whose deletion of kb sequence including exons 1-6 was completely linked to the ntl mutant . The CCDC154 was conserved between mouse and human and is wildly expressed in mouse tissues . The cellular localization of CCDC154 was in the early endosomes . Overexpression of CCDC154 inhibited cell proliferation of HEK293 cells by inducing G 2/M arrest . CCDC154 also inhibited tumor cell growth , and the soft agar assay revealed a significant decrease of the colony size of Hela cells upon transfection of CCDC154 . Our results indicate that CCDC154 is a novel osteopetrosis-related gene involved in cell cycle regulation and tumor suppression growth .
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0,
0,
0,
0,
0,
0
] |
22895184
|
Plant lectins , carbohydrate-binding proteins of non-immune origin , have recently been reported to induce programmed cell death ( including apoptosis and autophagy ) in many types of cancer cells . MicroRNAs ( miRNAs ) , small , non-coding endogenous RNAs , nucleotides ( nt ) in length , have been well characterized to play essential roles in regulation of the autophagy process in cancer ; however , how these miRNAs regulate autophagic pathways in plant lectin-induced cancer cells , still remains an enigma .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22882626
|
Natural killer ( NK ) and CD56(+) T cells are thought to play a central role in antitumour immunity . Their cytolytic activities are controlled by a variety of receptors including CD94 and killer immunoglobulin-like receptors ( KIR ) , which bind to major histocompatibility complex ( MHC ) class I molecules on target cells and mediate cell activation or inhibition . We have examined the numbers , phenotypes and antitumour cytotoxic functions of hepatic NK and CD56(+) T cells isolated from 22 patients with hepatic malignancy and 19 healthy donors . Flow cytometry revealed that NK cell numbers were increased among hepatic mononuclear cells in malignancy compared to histologically normal livers ( mean : 38% vs 27% ; P=0.03 ) , but CD56(+) T cell numbers were not ( 28% vs 27% ) . NK cells and CD56(+) T cells from tumour-bearing livers exhibited lymphokine-activated killing of K562 targets and T cell receptor-mediated lysis of P815 cells . The expression of CD94 and the KIR isotypes CD158a , CD158b and KIR3DL1 by CD56(+) T cells and NK cells was significantly and consistently reduced in tumour-bearing livers compared to healthy livers ( P<0.05 in all cases ) . Simultaneous ligation of CD158a , CD158b and KIR3DL1 caused an overall partial inhibition of CD56(+) T cell cytotoxic activity , suggesting that the observed reductions in KIR(+) cell numbers in malignancy are likely to lead to enhanced cytotoxicity . Our results suggest that , while hepatic CD56(+) T cells are not expanded in malignancy , downregulation of KIR and CD94 expression may be a mechanism by which the hepatic immune system can be activated to facilitate tumour rejection .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
12536240
|
The aim of this study was to determine whether isorhamnetin , an immediate 3'-O-methylated metabolite of quercetin , affects proliferation , cell death , and the cell cycle of human colon carcinoma ( HCT-116 ) cells . Isorhamnetin was found to be a potent antiproliferative agent in a dose- and time-dependent manner , with an IC50 of 72 μM after 48 h of incubation as estimated by MTT assay . Flow cytometry and fluorescence microscopy analysis showed that isorhamnetin exerted a stimulatory effect on apoptosis and necrosis . Isorhamnetin also increased the number of cells in G2/M phase . Serum deprivation appeared to potentiate the effects of isorhamnetin on cell death and facilitated cell cycle progression to G0/G1 phase . These results suggest that isorhamnetin might mediate inhibition of HCT-116 cell growth through the perturbation of cell cycle progression and are consistent with the notion that G2/M checkpoints could be a conserved target for flavonoids in human colon cancer cells , leading to apoptotic and necrotic death . These antiproliferative , apoptotic , necrotic , and cell cycle effects suggest that isorhamnetin may have clinically significant therapeutic and chemopreventive capabilities . To our knowledge , this is the first report of the effect of isorhamnetin on human colon cancer cells .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
20923189
|
Lentinula edodes mycelia ( L.E.M. ) is a dried powder extracted from shiitake mushrooms ( Lentinula edodes ) . We previously demonstrated that it has immunomodulatory effects . In this paper , the direct cytotoxic effects of the polysaccharide-rich fraction of L.E.M . ( L.E.M. ethanol precipitate ; LEP ) on HepG2 human hepatocellular carcinoma ( HCC ) cells were investigated . LEP directly killed the HepG2 cells efficaciously , but had only minor effects on normal rat hepatocytes and normal mouse dermal cells under the same conditions . Characteristic morphological changes associated with apoptosis such as shrinkage , rounding , and floating as well as chromatin condensation were confirmed ; terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling ( TUNEL ) staining was positive as determined by fluorescence microscopy analyses . The caspase-3 and -8 death receptor pathway was found largely responsible for the apoptotic death of HepG2 cells treated with LEP . In conclusion , LEP can directly induce apoptosis of HepG2 cells , and thus may have potential chemotherapeutic applications for the treatment of HCC .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
22791146
|
Photodynamic therapy ( PDT ) may trigger apoptosis or necrosis in cancer cells . Several steps in the induction and execution of apoptosis require high amounts of adenosine-5'-triphosphate ( ATP ) . Because the mitochondrial membrane potential ( delta psi ) decreases early in apoptosis , we raised the question about the mechanisms of maintaining a sufficiently high ATP level . We therefore monitored delta psi and the intracellular ATP level of apoptotic human epidermoid carcinoma cells ( A431 ) after photodynamic treatment with aluminum ( III ) phthalocyanine tetrasulfonate . A maximum of caspase-3-like activity and nuclear fragmentation was found at fluences of about 4 J cm(-2) . Under these conditions apoptotic cells reduced delta psi rapidly , while the ATP level remained high for 4-6 h after treatment for cells supplied with glucose . To analyze the contribution of glycolysis to the energy supply during apoptosis , experiments were carried out with cells deprived of glucose . These cells showed a rapid drop of ATP content and neither caspase activation nor nuclear fragmentation could be detected . We conclude that the use of glucose as a source of ATP is obligatory for the execution of PDT-induced apoptosis .
|
[
0,
0,
1,
0,
0,
0,
0,
1,
0,
0
] |
12511053
|
The type I insulin-like growth factor receptor ( IGF1R ) contributes to cancer cell biology . Disruption of IGF1R signaling alone or in combination with cytotoxic agents has emerged as a new therapeutic strategy . Our laboratory has shown that sequential treatment with doxorubicin ( DOX ) and anti-IGF1R antibodies significantly enhanced the response to chemotherapy . In this study , we examined whether inhibition of the tyrosine kinase activity of this receptor family would also enhance chemotherapy response . Cis-3-[3-(4-methyl-piperazin-l-yl)-cyclobutyl]-1-(2-phenyl-quinolin-7-yl)-imidazo[1,5-a]pyrazin-8-ylamine ( PQIP ) inhibited IGF1R and insulin receptor ( InsR ) kinase activity and downstream activation of ERK1/2 and Akt in MCF-7 and LCC6 cancer cells . PQIP inhibited both monolayer growth and anchorage-independent growth in a dose-dependent manner . PQIP did not induce apoptosis , but rather , PQIP treatment was associated with an increase in autophagy . We examined whether sequential or combination therapy of PQIP with DOX could enhance growth inhibition . PQIP treatment together with DOX or DOX followed by PQIP significantly inhibited anchorage-independent growth in MCF-7 and LCC6 cells compared to single agent alone . In contrast , pre-treatment with PQIP followed by DOX did not enhance the cytotoxicity of DOX in vitro . Furthermore , OSI-906 , a PQIP derivative , inhibited IGF-I signaling in LCC6 xenograft tumors in vivo . When given once a week , simultaneous administration of OSI-906 and DOX significantly enhanced the anti-tumor effect of DOX . In summary , these results suggest that timing and duration of the IGF1R/InsR tyrosine kinase inhibitors with chemotherapeutic agents should be evaluated in clinical trials . Long-term disruption of IGF1R/InsR may not be necessary when combined with cytotoxic chemotherapy .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
21850397
|
FCE 23762 ( 3 ' desamino-3'[2(s)methoxyl-4-morpholinyl]doxorubicin ) is a new doxorubicin ( Dx ) derivative that has been selected for clinical testing for its favourable antitumor characteristics , which include efficacy on Dx-resistant tumors . Immunosuppression is an undesirable side-effect of anti-cancer chemotherapy and the therapeutic efficacy of Dx is probably also related to its low immunotoxicity . It was , thus , of interest to compare the effects of FCE 23762 and its parental drug on the immune responses . Both compounds were injected i.v. into healthy mice at equitoxic doses and according to different treatment schedules . Single doses of FCE 23762 and Dx , given concomitant or after the antigen , suppressed at the same degree and dose-dependently the primary anti-SRBC antibody response . Following a multiple treatment schedule after the antigen , FCE 23762 was less suppressive than Dx on both primary and secondary antibody production . Differently from Dx , that was completely inactive , FCE 23762 moderately inhibited DTH reaction to SRBC , only at the highest single dose tested or for repeated administrations given simultaneously or after priming . Both drugs were totally ineffective in delaying skin allograft rejection . Since spleen cellularity and ex vivo lymphocyte proliferation to Con A and LPS were similarly impaired by the two drugs , the differentiated immunodepressive activity of FCE 23762 and Dx cannot be merely associated to their cytotoxic and antiproliferative action . The hypothesis of a selective effect on different regulatory cell subsets and/or immune mechanisms is discussed .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
1295379
|
Members of the Orai family are highly selective calcium ion channels that play an important role in store-operated calcium entry . Among the three known Orai isoforms , Orai3 has gained increased attention , notably for its emerging role in cancer . We recently demonstrated that Orai3 channels are over-expressed in breast cancer ( BC ) biopsies , and involved specifically in proliferation , cell cycle progression and survival of MCF-7 BC cells . Here , we investigate the downstream signaling mechanisms affected by Orai3 silencing , leading to the subsequent functional impact specifically seen in MCF-7 cancer cells . We report a correlation between Orai3 and c-myc expression in tumor tissues and in the MCF-7 cancer cell line by demonstrating that Orai3 down-regulation reduces both expression and activity of the proto-oncogene c-myc . This is likely mediated through the MAP Kinase pathway , as we observed decreased pERK1/2 levels and cell-cycle arrest in G1 phase after Orai3 silencing . Our results provide strong evidence that the c-myc proto-oncogene is influenced by the store-operated calcium entry channel Orai3 through the MAP kinase pathway . This connection provides new clues in the downstream mechanism linking Orai3 channels and proliferation , cell cycle progression and survival of MCF-7 BC cells .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
23266555
|
It is commonly believed that neurons remain in G(0) phase of the cell cycle indefinitely . Cell-cycle re-entry , however , is known to contribute to neuronal apoptosis . Moreover , recent evidence demonstrates the expression of cell-cycle proteins in differentiated neurons under physiological conditions . The functional roles of such expression remain unclear . Since DNA repair is generally attenuated by differentiation in most cell types , the cell-cycle-associated events in postmitotic cells may reflect the need to re-enter the cell cycle to activate DNA repair . We show that cyclin-C-directed , pRb-dependent G(0) exit activates the non-homologous end joining pathway of DNA repair ( NHEJ ) in postmitotic neurons . Using RNA interference , we found that abrogation of cyclin-C-mediated exit from G(0) compromised DNA repair but did not initiate apoptosis . Forced G(1) entry combined with prevention of G(1) --> S progression triggered NHEJ activation even in the absence of DNA lesions , but did not induce apoptosis in contrast to unrestricted progression through G(1) --> S. We conclude that G(0) --> G(1) transition is functionally significant for NHEJ repair in postmitotic neurons . These findings reveal the importance of cell-cycle activation for controlling both DNA repair and apoptosis in postmitotic neurons , and underline the particular role of G(1) --> S progression in apoptotic signaling , providing new insights into the mechanisms of DNA damage response ( DDR ) in postmitotic neurons .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20111042
|
Peptide 11 , CDPGYIGSR-NH2 , is a segment of laminin which blocks tumor cell invasion . A high affinity laminin receptor in tumor cells is thought to be blocked by the carboxyl-terminal YIGSR , and conformational energy calculations suggest that the glycine in YIGSR allows an important conformational bend . We replaced the YIGSR glycine residue in peptide 11 with either D-alanine or L-alanine to allow or disfavor the proposed glycine bend . We found the Gly7-->D-Ala7 analog to be equal to peptide 11 in inhibiting tumor cell invasion of basement membrane matrix . The Gly7-->L-Ala7 analog was much less capable of invasion inhibition . Two-dimensional 1H-1H NMR was used to study the solution conformations of the peptide 11 analogs . NOESY experiments revealed close NH-NH contacts in peptide 11 and the D-Ala7 analog , but not in the L-Ala7 analog . Molecular dynamics generated low energy structures with excellent NOE agreement for peptide 11 and its analogs . Both peptide 11 and the D-Ala7 analog , but not the less active L-Ala7 analog , were predicted to have similar bends around Gly7 or D-Ala7 . These results suggest that a bend in the YIGSR region of peptide 11 may be important for the binding of laminin to its metastasis-associated receptor .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
1460013
|
The mechanisms by which hematopoietic stem and progenitor cells ( HSC and HPC ) from myelodysplastic syndromes ( MDS ) undergo ineffective production of blood cells and disease transformation into acute myeloid leukemia remain to be investigated . It has been confirmed that increased production of reactive oxygen species ( ROS ) under various pathological conditions impairs HSC self-renewal and causes HSC premature exhaustion and BM suppression primarily via induction of HSC senescence , and oncogene induces accumulation of ROS and DNA damage and subsequently cellular senescence , which functions as an important barrier to prevent the growth of transformed cells to form a neoplasia . Here we investigated whether MDS CD34(+) cells enriched with HSC and HPC undergo senescence through accumulation of ROS and DNA damage and their action mechanisms . In this study , the percentages of SA-β-gal positive senescent CD34(+) cells increased in lower-risk MDS patients , but not in higher-risk MDS and AML patients , compared to that of healthy controls . The increases were associated with an elevated expression of p21 but not the activation of p38 . Further study found that there were increased ROS and DNA damage in CD34(+)CD38(-) cells enriched with HSC progression from lower-risk MDS , higher-risk MDS to AML . Therefore , these data suggest that CD34(+) cells from patients with lower-risk MDS present p21 dependent premature senescence , increased accumulation of ROS and DNA damage in CD34(+)CD38(-) cells could contribute to this process ; however , CD34(+) cells from patients with higher-risk MDS could develop some mechanisms to uncouple ROS and DNA damage induced senescence .
|
[
0,
1,
0,
1,
0,
1,
0,
0,
0,
1
] |
23219618
|
Even when patients with nonsmall cell lung cancer undergo surgical resection at an early stage , recurrent disease often impairs the clinical outcome . There are numerous causes potentially responsible for a relapse of the disease , one of them being extensive angiogenesis . The balance of at least two systems , VEGF VEGFR and Ang Tie , regulates vessel formation . The aim of this study was to determine the impact of surgery on the plasma levels of the main angiogenic factors during the first month after surgery in nonsmall cell lung cancer patients . The study group consisted of 37 patients with stage I nonsmall cell lung cancer . Plasma concentrations of Ang1 , Ang2 , sTie2 , VEGF , and sVEGF R1 were evaluated by ELISA three times : before surgical resection and on postoperative days 7 and 30 . The median of Ang2 and VEGF concentrations increased on postoperative day 7 and decreased on day 30 . On the other hand , the concentration of sTie2 decreased on the 7th day after resection and did not change statistically later on . The concentrations of Ang1 and sVEGF R1 did not change after the surgery . Lung cancer resection results in proangiogenic plasma protein changes that may stimulate tumor recurrences and metastases after early resection .
|
[
1,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
22550599
|
Aurora A kinase has drawn considerable attention as a therapeutic target for cancer therapy . However , the underlying molecular and cellular mechanisms of the anticancer effects of Aurora A kinase inhibition are still not fully understood . Herein , we show that depletion of Aurora A kinase by RNA interference ( RNAi ) in hepatocellular carcinoma ( HCC ) cells upregulated FoxO1 in a p53-dependent manner , which induces cell cycle arrest . Introduction of an RNAi-resistant Aurora A kinase into Aurora A-knockdown cells resulted in downregulation of FoxO1 expression and rescued proliferation . In addition , silencing of FoxO1 in Aurora A-knockdown cells allowed the cells to exit cytostatic arrest , which , in turn , led to massive cell death . Our results suggest that FoxO1 is responsible for growth arrest at the G 2/M phase that is induced by Aurora A kinase inhibition .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
23255113
|
PURPOSE To characterize the clinical features of a Chinese Uygur pedigree with primary open-angle glaucoma ( POAG ) and to identify mutations in two candidate genes , trabecular meshwork inducible glucocorticoid response ( MYOC/TIGR ) and human dioxin-inducible cytochrome P450 ( CYP1B1 ) . METHODS Twenty one members from a Chinese Uygur family of four generations were included in the study . All participants underwent complete ophthalmologic examinations . Five were diagnosed as POAG , four as glaucoma suspects , and the rest were asymptomatic . Molecular genetic analysis was performed on all subjects included in the study . All exons of CYP1B1 and MYOC were amplified by polymerase chain reaction ( PCR ) , sequenced and compared with a reference database . The variations detected were evaluated in available family members as well as 102 normal controls . Possible changes in structure and function of the protein induced by amino acid variance were predicted by bioinformatics analysis . RESULTS Elevated intraocular pressure and late-stage glaucomatous cupping of the optic disc were found in five patients of this family . A novel heterozygous missense mutation c.1151 A>G in exon 3 of MYOC was found in all five patients diagnosed as POAG and four glaucoma suspects , but not in the rest of the family members and 102 normal controls . This mutation caused an amino acid substitution of aspartic acid to glycine at position 384 ( p . D384G ) of the MYOC protein . This substitution may cause structural and functional changes of the protein based on bioinformatics analysis . No mutations were found in CYP1B1 . CONCLUSIONS Our study suggests that the novel mutation D384G of MYOC is likely responsible for the pathogenesis of POAG in this pedigree .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22876119
|
We have exploited properties of photosensitizers to study an aspect of the packing of chromatin in the cell nucleus . The fluorescent photosensitizers mesotetra(3-hydroxyphenyl) porphyrin and Photofrin II were both localized in the nuclear membrane and other membrane structures , but could not be found inside the nuclei . Light exposure of cells at 1 degrees C in the presence of the sensitizers induced DNA double-strand breaks . The length distributions of DNA fragments were determined by pulsed field gel electrophoresis . Because DNA damage is produced mainly via singlet oxygen diffusing less than 0.1 microns from the sensitizer , DNA double-strand breaks were supposedly produced within this distance of the nuclear membrane . Consistent with this , with prolonged illumination and with increasing concentrations of sensitizer the distribution of DNA fragment lengths reached a plateau level . In contrast , with the hydrophilic , intranuclear sensitizer meso-tetra(4-sulphonatophenyl)porphyrin , no such plateau level was found . The plateau distributions of DNA fragment lengths of different cell types had the same general shape with average fragment lengths ranging from 174 to 194 kilobasepairs . Particular genes , c-myc , fos and p53 , were found on broad distributions of photocleaved fragment lengths . The results indicate that on each side of the genes the locus of the chromatin fibre situated close to the nuclear membrane , varied randomly .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
1480490
|
We have investigated the possibility that photoexcited titanium dioxide ( TiO2 ) could inhibit the growth of malignant cells . We studied the anti-glioma effects of nano-TiO2 excited with ultraviolet A ( UVA ) irradiation both in vitro and in vivo . Transmission electron microscopy demonstrated that glioma cells take up TiO2 by phagocytosis , and vital staining revealed that TiO2 alone has no effect on glioma cell proliferation . However , if TiO2 was combined with UVA irradiation the proliferation rate was decreased significantly compared to controls ( P<0.05 ) . RT-PCR suggested that TiO2 induction of glioma cell apoptosis is associated with changes in the expression of genes encoding Bcl-2 family members . We then investigated the in vivo antitumor effects of combined TiO2 plus UVA treatment of established glioma tumors . TiO2 plus UVA led to pronounced areas of necrosis , elevated indices of apoptosis , delayed tumor growth , and increased survival compared with the TiO2-alone control group ( P<0.001 ) . Log-rank survival analysis showed that median survival duration was prolonged ( P<0.001 ) . These findings suggest that nano-TiO2 based photodynamic therapy has potential in the treatment of glioma .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20352345
|
The secretin receptor ( SR ) , a G protein-coupled receptor , mediates the effects of the gastrointestinal hormone secretin on digestion and water homeostasis . Recently , high SR expression has been observed in pancreatic ductal adenocarcinomas , cholangiocellular carcinomas , gastrinomas , and bronchopulmonary carcinoid tumors . Receptor overexpression associates with enhanced secretin-mediated signaling , but whether this molecule plays an independent role in tumorigenesis is currently unknown . We recently discovered that pheochromocytomas developing in rats affected by the MENX ( multiple endocrine neoplasia-like ) syndrome express at very high-level Sctr , encoding SR . We here report that SR are also highly abundant on the membranes of rat adrenal and extraadrenal pheochromocytoma , starting from early stages of tumor development , and are functional . PC12 cells , the best characterized in vitro pheochromocytoma model , also express Sctr at high level . Thus , we used them as model to study the role of SR in neoplastic transformation . Small interfering RNA-mediated knockdown of Sctr decreases PC12 cells proliferation and increases p27 levels . The proproliferative effect of SR in PC12 cells is mediated , in part , by the phosphatidylinositol 3 kinase ( PI3K)/serine-threonine protein kinase ( AKT ) pathway . Transfection of Sctr in Y1 adrenocortical carcinoma cells , expressing low endogenous levels of Sctr , stimulates cell proliferation also , in part , via the PI3K/AKT signaling cascade . Because of the link between SR and PI3K/AKT signaling , tumor cells expressing high levels of the receptor ( MENX-associated primary pheochromocytoma and NCI-H727 human bronchopulmonary carcinoid cells ) respond well and in a SR-dependent manner to PI3K inhibitors , such as NVP-BEZ235 . The association between SR levels and response to PI3K inhibition might open new avenues for the treatment of tumors overexpressing this receptor .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
22692904
|
Acute leukemia is a disorder of the hematopoietic system characterized by the expansion of a clonal population of cells blocked from differentiating into mature cells . Recent studies have shown that chalcones and their derivatives induce apoptosis in different cell lines . Since new compounds with biological activity are needed , the aim of this study was to evaluate the cytotoxic effect of three synthetic chalcones , derived from 1-naphthaldehyde and 2-naphthaldehyde , on human acute myeloid leukemia K562 cells and on human acute lymphoblastic leukemia Jurkat cells . Based on the results , the most cytotoxic compound ( A1 ) was chosen for further analysis in six human acute leukemia cells and in a human colon adenocarcinoma cell line ( HT-29 ) . Chalcone A1 significantly reduced the cell viability of K562 , Jurkat , Kasumi , U937 , CEM and NB4 cells in a concentration and time-dependent manner when compared with the control group ( IC(50) values between ∼1.5μM and 40μM ) . It was also cytotoxic to HL-29 cells . To further examine its effect on normal cells , peripheral blood lymphocytes collected from healthy volunteers were incubated with the compound . It has also been incubated with human fibroblasts cultured from bone marrow ( JMA ) . Chalcone A1 is non-cytotoxic to PBL cells and to JMA cells . A1 caused significant cell cycle arrest in all phases according to the cell line , and increased the proportion of cells in the sub G0/G1 phase . To evaluate whether this chalcone induced cell death via an apoptotic or necrotic pathway , cell morphology was examined using fluorescence microscopy . Cells treated with A1 at IC(50) demonstrated the morphological characteristic of apoptosis , such as chromatin condensation and formation of apoptotic bodies . Apoptosis was confirmed by externalization of phosphatidylserine , which was detected by the Annexin V-FITC method , and by DNA fragmentation . The results suggest that chalcone A1 has potential as a new lead compound for cancer therapy .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
23257665
|
DNA repair is an essential cellular process required to maintain genomic stability . Every cell is subjected to thousands of DNA lesions daily under normal physiological conditions . Ionizing radiation ( IR ) is a major DNA damaging agent that can be produced by both natural and man-made sources . A common source of radiation exposure is through its use in medical diagnostics or treatments such as for cancer radiotherapy where relatively high doses are received by patients . To understand the detailed DNA repair gene transcription response to high dose IR , gene expression exon array studies have been performed and the response to radiation in two divergent cell types , lymphoblastoid cell lines and primary fibroblasts , has been examined . These exon arrays detect expression levels across the entire gene , and have the advantage of high sensitivity and the ability to identify alternative transcripts . We found a selection of DNA repair genes , including some not previously reported , that are modulated in response to radiation . Detailed dose and time course kinetics of DNA repair transcription was conducted and results have been validated utilizing PCR methods . Alternative transcription products in response to IR were identified in several DNA repair genes including RRM2B and XPC where alternative initiation sites were found . These investigations have advanced the knowledge about the transcriptional response of DNA repair .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23285288
|
A novel compound 2-arylidene-4,7-dimethyl indan-1-one synthesized was screened for anticancer effect against the human breast adenocarcinoma cell line , MCF-7 . An IC50 value of > or = 80 microM , nontoxic to the normal breast cell line HBL-100 , showed complete inhibition of the MCF-7 cells . Analysis of mechanisms showed nuclear fragmentation and DNA laddering in gel electrophoresis . GSH and GR levels were found to be reduced after the compound treatment . Cell cycle analysis using fluorescent cytometry revealed G2/M phase arrest , which indicates the compound deserves consideration for further studies against cancer .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
20681405
|
Adipose tissue growth and development are thought to be associated with angiogenesis and extracellular matrix remodeling . Because ginseng has been shown to inhibit angiogenesis and matrix metalloproteinase ( MMP ) activity , we hypothesized that adipose tissue growth and obesity can be regulated by Korean ginseng ( Panax ginseng C.A. Meyer ) . Wild-type C57BL/6J mice were fed for 8 weeks with a low fat diet , a high fat diet ( HFD ) , or HFD supplemented with 0.5% or 5% Korean red ginseng extract . We measured body weight , adipose tissue mass , food intake , MMP activity , and the expression of genes involved in angiogenesis and MMPs . Administering ginseng to HFD-induced obese mice produced reductions in body weight and adipose tissue mass compared with untreated counterparts . Ginseng treatment decreased blood vessel density and MMP activity in adipose tissues . Ginseng also reduced mRNA levels of angiogenic factors ( e.g. , VEGF-A and FGF-2 ) and MMPs ( e.g. , MMP-2 and MMP-9 ) , whereas it increased mRNA levels of angiogenic inhibitors ( e.g. , TSP-1 , TIMP-1 , and TIMP-2 ) in adipose tissues . These results demonstrate that ginseng effectively reduces adipose tissue mass and prevents obesity in diet-induced obese mice and that this process may be mediated in part through the anti-angiogenic actions of ginseng .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
23232078
|
Levels of regulatory T cells ( Tregs ) are increased in different cancer types as well as in inflammatory diseases , such as rheumatoid arthritis . Treg accumulation may result from aberrant proliferation and trafficking as well as greater resilience to oxidative stress compared with conventional T cells . This enhanced antioxidative capacity of Tregs possibly serves as feedback inhibition during inflammation and prevents uncontrolled immune reactions by favoring survival of suppressor rather than effector cells . In this study , we demonstrate that human Tregs express and secrete higher levels of thioredoxin-1 , a major antioxidative molecule . Thioredoxin-1 has an essential role in maintaining their surface thiol density as the first line of antioxidative defense mechanisms and is sensitive to proinflammatory stimuli , mainly tumor necrosis factor-α , in a nuclear factor-κB-dependent fashion . The antiapoptotic and oncogenic potential of ( secreted ) Trx-1 suggests that it may exert effects in Tregs beyond redox regulation .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
21030559
|
Lewis y ( LeY ) antigen is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface . Overexpression of LeY is frequently observed in epithelial-derived cancers and has been correlated to the pathological staging and prognosis . However , the effects of LeY on ovarian cancer are not yet clear . Previously , we transfected the ovarian cancer cell line RMG-I with the α1,2-fucosyltransferase gene to obtain stable transfectants , RMG-I-H , that highly express LeY . In the present study , we examined the proliferation , tumorigenesis , adhesion and invasion of the cell lines with treatment of LeY monoclonal antibody ( mAb ) . Additionally , we examined the expression of TGF-β1 , VEGF and b-FGF in xenograft tumors . The results showed that the proliferation and adhesion in vitro were significantly inhibited by treatment of RMG-I-H cells with LeY mAb . When subcutaneously inoculated in nude mice , RMG-I-H cells produced large tumors , while mock-transfected cells RMG-I-C and the parental cells RMG-I produced small tumors . Moreover , the tumor formation by RMG-I-H cells was inhibited by preincubating the cells with LeY mAb . Notably , the expression of TGF-β1 , VEGF and b-FGF all increased in RMG-I-H cells . In conclusion , LeY plays an important role in promoting cell proliferation , tumorigenecity and adhesion , and these effects may be related to increased levels of growth factors . The LeY antibody shows potential application in the treatment of LeY-positive tumors .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
21152298
|
Cyclin E2 , but not cyclin E1 , is included in several gene signatures that predict disease progression in either tamoxifen-resistant or metastatic breast cancer . We therefore examined the role of cyclin E2 in antiestrogen resistance in vitro and its potential for therapeutic targeting through cyclin-dependent kinase ( CDK ) inhibition . High expression of CCNE2 , but not CCNE1 , was characteristic of the luminal B and HER2 subtypes of breast cancer and was strongly predictive of shorter distant metastasis-free survival following endocrine therapy . After antiestrogen treatment of MCF-7 breast cancer cells , cyclin E2 mRNA and protein were downregulated and cyclin E2-CDK2 activity decreased . However , this regulation was lost in tamoxifen-resistant ( MCF-7 TAMR ) cells , which overexpressed cyclin E2 . Expression of either cyclin E1 or E2 in T-47D breast cancer cells conferred acute antiestrogen resistance , suggesting that cyclin E overexpression contributes to the antiestrogen resistance of tamoxifen-resistant cells . Ectopic expression of cyclin E1 or E2 also reduced sensitivity to CDK4 , but not CDK2 , inhibition . Proliferation of tamoxifen-resistant cells was inhibited by RNAi-mediated knockdown of cyclin E1 , cyclin E2 , or CDK2 . Furthermore , CDK2 inhibition of E-cyclin overexpressing cells and tamoxifen-resistant cells restored sensitivity to tamoxifen or CDK4 inhibition . Cyclin E2 overexpression is therefore a potential mechanism of resistance to both endocrine therapy and CDK4 inhibition . CDK2 inhibitors hold promise as a component of combination therapies in endocrine-resistant disease as they effectively inhibit cyclin E1 and E2 overexpressing cells and enhance the efficacy of other therapeutics .
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[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
22564725
|
OBJECTIVES To evaluate the impact of the category of unclassified renal cell carcinoma ( URCC ) on survival following nephrectomy . METHODS Patients with clear cell RCC ( ccRCC , n = 3048 ) and URCC ( n = 38 ) were identified . Patients with URCC were matched 4:1 with ccRCC patients based on year of surgery , symptoms at presentation , tumor size , stage , regional lymph node involvement , metastases , grade , coagulative tumor necrosis , and sarcomatoid differentiation . Survival was estimated using the Kaplan-Meier method and compared between ccRCC and URCC patients using log-rank tests . RESULTS Patients with URCC were more likely to have regional lymph node involvement ( P <.001 ) , higher grade ( P <.001 ) , tumor necrosis ( P <.001 ) , and sarcomatoid differentiation ( P <.001 ) as compared to patients with ccRCC . Overall survival was not significantly different between URCC and ccRCC patients in either the unmatched ( P = .337 ) or matched ( P = .345 ) cohorts . Cancer-specific survival was significantly worse for URCC patients compared with unmatched ccRCC patients ( P = .020 ) . However , this difference was not statistically significant when the URCC patients were compared with the matched cohort ( P = .688 ) . Distant metastases-free survival was somewhat worse for M0 URCC patients compared with unmatched M0 ccRCC patients ( P = .063 ) , but not in the matched cohort ( P = .788 ) . CONCLUSIONS Although URCC is more likely to present with advanced clinicopathologic features compared with ccRCC , no statistically significant differences in outcome were noted after adjusting for these features in a matched analysis .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20223503
|
SCOPE Glyceollins are a novel class of soybean phytoalexins with potential cancer-preventive and antiestrogenic effects . The angiogenic cascade during tumor development consists of the release of angiogenic factors and binding of angiogenic factors to receptors on endothelial cells to activate downstream signaling pathways . However , the potential medicinal value of glyceollins , especially in antiangiogenesis , remains unexplored . METHODS AND RESULTS Here , we investigated the antiangiogenic activity of glyceollins and their underlying mechanisms . Glyceollins inhibited vascular endothelial growth factor ( VEGF ) or basic fibroblast growth factor ( bFGF ) induced in vitro angiogenic activity . Glyceollins inhibited VEGF receptor-2 or FGF receptor-1 activity and their downstream signaling pathways such as extracellular regulated kinase 1/2 , c-Jun N-terminal kinase , as well as p38 mitogen-activated protein kinase and focal adhesion kinase induced by VEGF or bFGF . Glyceollins significantly suppressed VEGF receptor-2 kinase activity assayed by the ELISA . Glyceollins significantly attenuated in vivo and ex vivo microvessel development in a dose-dependent manner and tumor growth by suppressing microvessel density in Lewis lung carcinoma ( LLC ) mouse xenograft . CONCLUSION Thus , glyceollins , elicited ingredients of soy source , target the signaling pathways mediated by VEGF or bFGF , providing new perspectives into potential therapeutics for preventing and treating hypervascularized diseases including cancer .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
23229497
|
We studied whether feeding pregnant female rats different high fat diets affects structural zones in the spleen and lymph nodes , involved in production of T and B cells , as well as cell kinetics and apoptosis in some offspring with mammary glands tumors . Rat mothers were fed either a 7% or 15% corn-oil or a 7% or 15% olive-oil diet . At four weeks of age , female offspring ( n=10-15 per group ) were transferred to 7% corn oil diet . Five-week old offspring were exposed twice to the carcinogen , dimethylbenz(a)antracene ( 10 mg/rat/week ) . Three months later , tumors were counted and sized , and samples from the spleen , axillary lymph nodes and tumors collected for immunohistochemical analyses . Feeding the mothers with both the 7% and 15% olive-oil diets significantly increased the number of tumor-free rats in offspring . Tumors were characterized with active mitosis , intensive lymphoid infiltration inside a knot and high rates of apoptosis , particularly in tumors obtained from rats whose mothers were fed the 15% olive-oil diet . In the spleen , the 15% olive-oil diet significantly increased the areas of the follicles and germinal centers but only in tumor-free rats . In tumor-bearing rats , areas of germinal centers increased compared to the 7% olive-oil diet . The 15% olive-oil diet increased all areas of the lymph nodes in tumor-free rats , while in tumor-bearing rats , this diet increased the areas of the cortex and mantle layer . We conclude that exposure to various diets in utero and during lactation affects the immune system . In addition , the promotion of apoptosis may play a key role in the mechanisms involved in the transplacental effects on mammary tumor development as seen using a 15% olive-oil diet , similar to the high fat diets of Mediterranean countries .
|
[
0,
1,
0,
0,
0,
0,
0,
1,
0,
0
] |
12430006
|
Among several types of DNA lesions , the DNA double strand breaks ( DSBs ) are one of the most deleterious and harmful . Mammalian cells mount a coordinated response to DSBs with the aim of appropriately repair the DNA damage . Indeed , failure of the DNA damage response ( DDR ) can lead to the development of cancer-prone genetic diseases . The identification and development of drugs targeting proteins involved in the DDR is even more investigated , as it gives the possibility to specifically target cancer cells . Indeed , the administration of DNA repair inhibitors could be combined with chemo- and radiotherapy , thus improving the eradication of tumor cells . Here , we provide an overview about DSBs damage response , focusing on the role of the DSBs repair mechanisms , of chromatin modifications , and of the cancer susceptibility gene BRCA1 which plays a multifunctional role in controlling genome integrity . Moreover , the most investigated DSBs enzyme inhibitors tested as potential therapeutic agents for anti-cancer therapy are reported .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20423312
|
Gene trapping is a method of inserting DNA into the genome at random , generating insertional mutations throughout the genome . The efficiency of retroviral gene trapping is not sufficient in part because of a strong preference for retroviral integration near transcription start sites . In contrast , lentiviral vectors strongly favor integration in the entire region of highly active genes , suggesting that lentiviral vectors would improve the efficiency of gene trapping . In this study , we constructed both lentiviral and retroviral gene-trap vectors and analyzed integration sites in mouse embryonic stem ( ES ) cells . The frequency of false-positive gene-trap events was about 12-fold higher for the retroviral vector compared to the lentiviral vector . Within intragenic regions , most of the retroviral vector integration sites were found in the 5 ' untranslated region , while the lentiviral vector integrated uniformly throughout transcriptional units . The trapping efficiency of unique genes was significantly higher for the lentiviral vector ( than for the retroviral vector ( Our data demonstrate that the lentiviral vector can trap the active genes more efficiently than the retroviral vector and will facilitate efficient generation of gene-trap libraries not only in ES cells but also in a wide variety of cell lines and primary cells .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22842569
|
Myotonia congenita-inducing mutations in the muscle chloride channel CLC-1 normally result in reduced open probability ( P ( o) ) of this channel . One well-accepted mechanism of the dominant inheritance of this disease involves a dominant-negative effect of the mutation on the function of the common-gate of this homodimeric , double-barreled molecule . We report here a family with myotonia congenita characterized by muscle stiffness and clinical and electrophysiologic myotonic phenomena transmitted in an autosomal dominant pattern . DNA sequencing of DMPK and ZNF9 genes for myotonic muscular dystrophy types I and II was normal , whereas sequencing of CLC-1 encoding gene , CLCN1 , identified a single heterozygous missense mutation , G233S . Patch-clamp analyses of this mutant CLC-1 channel in Xenopus oocytes revealed an increased P ( o ) of the channel's fast-gate , from in the wild type to >0.9 in the mutant at -90 mV . In contrast , the mutant exhibits a minimal effect on the P ( o ) of the common-gate . These results are consistent with the structural prediction that the mutation site is adjacent to the fast-gate of the channel . Overall , the mutant could lead to a significantly reduced dynamic response of CLC-1 to membrane depolarization , from a fivefold increase in chloride conductance in the wild type to a twofold increase in the mutant-this might result in slower membrane repolarization during an action potential . Since expression levels of the mutant and wild-type subunits in artificial model cell systems were unable to explain the disease symptoms , the mechanism leading to dominant inheritance in this family remains to be determined .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22790975
|
OBJECTIVE Hepatocellular carcinoma ( HCC ) is a highly vascularized tumor in which neoangiogenesis contributes to growth and metastasis . We assessed the safety , efficacy , and potential biomarkers of activity of bevacizumab in patients with advanced HCC . METHODS In this phase II trial , eligible patients received bevacizumab , 5 mg/kg or 10 mg/kg every 2 weeks . The disease-control rate at 16 weeks ( 16W-DCR ) was the primary endpoint . Circulating endothelial cells ( CECs ) and plasma cytokines and angiogenic factors ( CAFs ) were measured at baseline and throughout treatment . RESULTS The 16W-DCR was 42% ( 95% confidence interval , 27%-57% ) . Six of the 43 patients who received bevacizumab achieved a partial response ( objective response rate [ ORR ] , 14% ) . Grade 3-4 asthenia , hemorrhage , and aminotransferase elevation occurred in five ( 12% ) , three ( 7% ) , and three ( 7% ) patients , respectively . During treatment , placental growth factor markedly increased , whereas vascular endothelial growth factor ( VEGF)-A dramatically decreased ( p < .0001 ) ; soluble VEGF receptor-2 ( p < .0001 ) and CECs ( p = .03 ) transiently increased on day 3 . High and increased CEC counts at day 15 were associated with the ORR ( p = .04 ) and the 16W-DCR ( p = .02 ) , respectively . Lower interleukin ( IL)-8 levels at baseline ( p = .01 ) and throughout treatment ( p ≤ .04 ) were associated with the 16W-DCR . High baseline IL-8 and IL-6 levels predicted shorter progression-free and overall survival times ( p ≤ .04 ) . CONCLUSION Bevacizumab is active and well tolerated in patients with advanced HCC . The clinical value of CECs , IL-6 , and IL-8 warrants further investigation .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
22707516
|
Induced pluripotent stem cells ( iPSCs ) generated by epigenetic reprogramming of personal somatic cells have limited therapeutic capacity for patients suffering from genetic disorders . Here we demonstrate restoration of a genomic mutation heterozygous for Pkd1 ( polycystic kidney disease 1 ) deletion ( Pkd1(+/-) to Pkd1(+/R+) ) by spontaneous mitotic recombination . Notably , recombination between homologous chromosomes occurred at a frequency of 1 per 10,000 iPSCs . Southern blot hybridization and genomic PCR analyses demonstrated that the genotype of the mutation-restored iPSCs was indistinguishable from that of the wild-type cells . Importantly , the frequency of cyst generation in kidneys of adult chimeric mice containing Pkd1(+/R+) iPSCs was significantly lower than that of adult chimeric mice with parental Pkd1(+/-) iPSCs , and indistinguishable from that of wild-type mice . This repair step could be directly incorporated into iPSC development programmes prior to cell transplantation , offering an invaluable step forward for patients carrying a wide range of genetic disorders .
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[
0,
0,
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0,
0,
0,
0,
0,
0,
0
] |
22347511
|
An epidemiological survey was conducted in the Seine estuary and in two smaller and relatively preserved estuaries on the French Atlantic coast in order to estimate the occurrence of liver lesions in European flounder , Platichthys flesus , and also to seek putative risk factors for the recorded pathologies . Four hundred and seventy-eight fish of both sexes and of different size ranges were sampled in the three studied areas , 338 of which in the Seine estuary . All fish were examined for histopathological liver lesions , while DNA adducts and otoliths were analyzed on a subsample . Five categories of hepatic lesions were recorded with the following prevalence for the Seine estuary : 36.7 % inflammations , 8 % parasites ( mainly encysted nematodes ) , 6.5 % foci of cellular alteration ( FCA ) , 5.3 % foci of necrosis or regeneration ( FNR ) , and 1.5 % tumors . Inflammation occurrence increased according to age , contrary to parasitic infestations and FCA which were more prevalent in young fish , notably those of <1 year old ( group 0 ) . Tumors were only observed in females of more than two winters . Females exhibited a higher prevalence of tumors ( 3.0 % ) and FCA ( 6.5 % ) than males ( 0 and 2.6 % , respectively ) . Parasitic and infectious lesions and FNR were equally distributed in males and females . The prevalence of FNR was also shown to vary according to sampling season , with significantly more occurrences of liver necrosis in the fish collected in summer than in spring . Spatial differences were observed with a higher occurrence of encysted parasites in flounders from the upper Seine estuary , while inflammations predominated in flounders living downstream . Temporal trends were also noted , with an increased prevalence of parasitic infestations , inflammations , and FCA in the 2002-2003 period in comparison to the 1996-1997 one . The three flounder populations from the Seine estuary ( Normandy ) , Ster estuary ( Brittany ) , and Bay of Veys ( Normandy ) showed different spectra of hepatic lesions . Flounders from the Bay of Veys had relatively few liver lesions as compared to flounders from the two other estuaries . Flounders from the Ster estuary exhibited the highest prevalence of parasites ( 37.2 % ) and inflammations ( 51.1 % ) . Finally , FCA and liver tumors occurred at very similar levels in both flounder populations from the Seine and the Ster estuaries . Group 0 flounders inhabiting the upper Seine estuary were more prone to parasitic and pre-neoplastic hepatic lesions and had higher levels of liver DNA adducts than the older ones living downstream . It was postulated that group 0 European flounders may serve as valuable bioindicators for assessing the quality of estuarine waters and the health status of euryhaline fish populations .
|
[
0,
0,
0,
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0,
1,
0,
0,
0,
1
] |
23161498
|
The most potent tumorigen identified among the polycyclic aromatic hydrocarbons ( PAH ) is the nonplanar fjord region dibenzo[a,l]pyrene ( DB[a,l]P ) . It is metabolically activated in vivo through the widely studied diol epoxide ( DE ) pathway to form covalent adducts with DNA bases , predominantly guanine and adenine . The ( +)-11S,12R,13R,14S DE enantiomer forms adducts via its C14 position with the exocyclic amino group of guanine . Here , we present the first nuclear magnetic resonance solution structure of a DB[a,l]P-derived adduct , the 14R-(+)-trans-anti-DB[a,l]P-N(2)-dG ( DB[a,l]P-dG ) lesion in double-stranded DNA . In contrast to the stereochemically identical benzo[a]pyrene-derived N(2)-dG adduct ( B[a]P-dG ) in which the B[a]P rings reside in the B-DNA minor groove on the 3'-side of the modifed deoxyguanosine , in the DB[a,l]P-derived adduct the DB[a,l]P rings intercalate into the duplex on the 3'-side of the modified base from the sterically crowded minor groove . Watson-Crick base pairing of the modified guanine with the partner cytosine is broken , but these bases retain some stacking with the bulky DB[a,l]P ring system . This new theme in PAH DE-DNA adduct conformation differs from ( 1 ) the classical intercalation motif in which Watson-Crick base pairing is intact at the lesion site and ( 2 ) the base-displaced intercalation motif in which the damaged base and its partner are extruded from the helix . The structural considerations that lead to the intercalated conformation of the DB[a,l]P-dG lesion in contrast to the minor groove alignment of the B[a]P-dG adduct , and the implications of the DB[a,l]P-dG conformational motif for the recognition of such DNA lesions by the human nucleotide excision repair apparatus , are discussed .
|
[
0,
0,
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0,
0,
1,
0,
0,
0,
0
] |
23121427
|
Three normal human diploid cell strains were transfected with an activated Ha-ras oncogene ( EJ ras ) or SV40 T-antigen . Multiple clones were examined for morphological alterations , growth requirements , ability to grow under anchorage independent conditions , immortality and tumorigenicity in nude mice . Clones expressing SV40 T-antigen alone or in combination with ras protein p21 were significantly radioresistant as compared with their parent cells or clones transfected with the neo gene only . This radioresistant phenotype persisted in post-crisis , immortalized cell lines . Cells transfected with EJ ras alone showed no morphological alterations nor significant changes in radiosensitivity . Cell clones expressing ras and/or SV40 T-antigen showed a reduced requirement for serum supplements , an increase in aneuploidy and chromosomal aberrations , and enhanced growth in soft agar as an early cellular response to SV40 T-antigen expression . The sequential order of transfection with SV40 T-antigen and ras influenced radio-sensitivity but not the induction of morphological changes . These data suggest that expression of the SV40 T-antigen but not activated Ha-ras plays an important role in the radiosensitivity of human diploid cells . The radioresistant phenotype in SV40 T transfected cells was not related to the enhanced level of genetic instability seen in pre-crisis and newly immortalized cells , nor to the process of immortalization itself .
|
[
0,
0,
0,
1,
0,
1,
0,
0,
0,
0
] |
1355514
|
Genetic and molecular analyses mainly in Arabidopsis and in some other plants have demonstrated involvement of light signaling in cell cycle regulation . In this report , we show light-mediated activation of the promoter of AtPol\u03bb gene , a homolog of mammalian DNA polymerase \u03bb in Arabidopsis thaliana and an important component of DNA damage repair/recombination machinery in plants . Analyses of the light-mediated promoter activity using various deletion versions of AtPol\u03bb promoter in transformed Arabidopsis and tobacco ( Nicotiana tabaccum ) plants indicate that a 130-bp promoter region between -536 and -408 of AtPol\u03bb promoter is essential for light-induced regulation of AtPol\u03bb expression . DNA-protein interaction studies reveal that an ATCT-motif and AE-box light-responsive elements in the light-regulated promoter region confer light responsiveness of AtPol\u03bb promoter . DNA-binding analysis has identified a 63-kDa trans-acting protein factor which showed specific binding to ATCT-motif , while another trans-acting factor of kDa was found to bind specifically to both ATCT and AE-box sequences . The 52-kDa protein has been identified as B3-domain transcription factor by MALDI-TOF/MS analysis . Overall , our results provide novel information on the role of light signaling in regulation of expression of an important component of DNA repair machinery in plants .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
21947619
|
Dose-dense ( DD ) regimens of combination chemotherapy may produce superior clinical outcomes , but the basis for these effects are not completely clear . In this study , we assessed whether a DD combinatorial regimen of low-dose cisplatin and paclitaxel produces superior immune-mediated efficacy when compared with a maximum tolerated dose ( MTD ) regimen in treating platinum-resistant ovarian cancer as modeled in mice . Immune responses generated by the DD regimen were identified with regard to the immune cell subset responsible for the antitumor effects observed . The DD regimen was less toxic to the immune system , reduced immunosuppression by the tumor microenvironment , and triggered recruitment of macrophages and tumor-specific CD8(+) T-cell responses to tumors [ as determined by interleukin ( IL)-2 and IFN-γ secretion ] . In this model , we found that the DD regimen exerted greater therapeutic effects than the MTD regimen , justifying its further clinical investigation . Fourteen patients with platinum-resistant relapse of ovarian cancer received DD chemotherapy consisting of weekly carboplatin ( AUC2 ) and paclitaxel ( 60-80 mg/m(2) ) as the third- or fourth-line treatment . Serum was collected over the course of treatment , and serial IFN-γ and IL-2 levels were used to determine CD8(+) T-cell activation . Of the four patients with disease control , three had serum levels of IL-2 and IFN-γ associated with cytotoxic CD8(+) T-cell activity . The therapeutic effect of the DD chemotherapy relied on the preservation of the immune system and the treatment-mediated promotion of tumor-specific immunity , especially the antitumor CD8(+) T-cell response . Because the DD regimen controlled drug-resistant disease through a novel immune mechanism , it may offer a fine strategy for salvage treatment . Cancer Res ; 73(1) ; 119-27. �2012 AACR .
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[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23108141
|
In this study , laboratory experiments were carried out in order to come to a better understanding of the fate of polycyclic aromatic hydrocarbons ( PAHs ) in the marine environment and especially on their bioaccumulation , biotransformation and genotoxic effects in fish . Juveniles of turbot ( Scophthalmus maximus ) were exposed to PAHs through different routes via ( 1 ) a mixture of dissolved PAHs , ( 2 ) a PAH-polluted sediment and ( 3 ) an oil fuel elutriate . Fish were exposed 4 days followed by a 6-day depuration period . In each experiment , PAH concentrations in the seawater of the tanks were analysed regularly by gas chromatography coupled with mass spectrometry . Muscle and liver samples were also analysed for parent PAH levels and PAH bioconcentration factors were calculated . Biotransformation was evaluated by measuring the levels of PAH metabolites in fish bile . Genotoxicity was assessed by the alkaline comet assay . Regardless of exposure route , the parent PAH concentrations in the liver and muscle showed a peak level 1 day after the beginning of the exposure , followed by a decrease up to the background level towards the end of the experiment , except for the exposure to dissolved PAHs for which levels were relatively low throughout the study . As a consequence , no bioaccumulation was observed in fish tissues at the end of the experiment . In contrast , regardless of exposure routes , a rapid production of biliary metabolites was observed throughout the whole exposure experiment . This was especially true for 1-hydroxypyrene , the major metabolite of pyrene . After 6 days of recovery in clean water , a significant decrease in the total metabolite concentrations occurred in bile . Fish exposed through either route displayed a significant increase in DNA strand breaks after 4 days of exposure , and significant correlations were observed between the level of biliary PAH metabolites and the level of DNA lesions in fish erythrocytes . Overall results indicate that exposure to either a mixture of dissolved PAHs , a PAH-contaminated sediment or a dispersed oil fuel elutriate leads to biotransformation and increase in DNA damage in fish . The quantification of PAH metabolites in bile and DNA damage in erythrocytes appear to be suitable for environmental monitoring of marine pollution either in the case of accidental oil spills or sediment contamination .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23247530
|
Muir-Torre syndrome ( MTS ) , a phenotypic variant of the more common hereditary nonpolyposis colorectal cancer syndrome , or Lynch syndrome , is an autosomal dominantly inherited condition that combines at least one cutaneous sebaceous neoplasm and at least one visceral malignancy . Most patients ( with MTS carry mutations in the MSH2 gene ; less than 10% of the cases are associated with a mutation MLH1 gene , and only 3 MTS patients with a pathogenic MSH6 mutation have been previously documented . We report a family affected with MTS in which 3 members ( father and 2 sons ) were found to harbor a missense mutation c.2633T>C ( p.V878A ) in exon 4 of the MSH6 gene .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22814321
|
The immune system of vertebrates is able to detect bacterial DNA based on the presence of unmethylated CpG motifs . We examined the therapeutic potential of oligodeoxynucleotides with CpG motifs ( CpG ODN ) in a colon carcinoma model in BALB/c mice . Tumors were induced by s.c. injection of syngeneic C26 cells or Renca kidney cancer cells as a control . Injection of CpG ODN alone or in combination with irradiated tumor cells did not protect mice against subsequent tumor challenge . In contrast , weekly injections of CpG ODN into the margin of already established tumors resulted in regression of tumors and complete cure of mice . The injection site was critical , since injection of CpG ODN at distant sites was not effective . Mice with two bilateral C26 tumors rejected both tumors upon peritumoral injection of one tumor , indicating the development of a systemic immune response . The tumor specificity of the immune response was demonstrated in mice bearing a C26 tumor and a Renca tumor at the same time . Mice that rejected a tumor upon peritumoral CpG treatment remained tumor free and were protected against rechallenge with the same tumor cells , but not with the other tumor , demonstrating long term memory . Tumor-specific CD8 T cells as well as innate effector cells contributed to the antitumor activity of treatment . In conclusion , peritumoral CpG ODN monotherapy elicits a strong CD8 T cell response and innate effector mechanisms that seem to act in concert to overcome unresponsiveness of the immune system toward a growing tumor .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
12244187
|
Glioblastoma multiforme ( GBM ) and oxidative stress are closely linked . Oxidative stress affects many signaling pathways and may cause the induction of autophagy . The NF-E2-related factor 2 ( Nrf2)/Kelch-like ECH-associated protein 1 ( Keap1 ) signaling pathway is the main pathway responsible for cell defense against oxidative stress and Nrf2 is a critical transcription factor related with cancer multidrug resistance . However , the relation between Nrf2 and regulation of autophagy is not well understood . In this study , we used temozolomide ( TMZ ) , which inhibited the viability of GBM cells mainly by inducing autophagic cell death and explored the role of Nrf2 downregulation on autophagy induced by TMZ in GBM cells . In U251-Si-Nrf2 48h after transfection the protein levels of Nrf2 were significantly downregulated , while the protein levels of LC3B-II increased by western blot analysis . Knockdown of Nrf2 also led to a significant increase of autophagic vacuoles and acidic vesicular organelles ( AVOs ) , revealed by trans-mission electron microscopy ( TEM ) and acridine orange ( AO ) staining using flow cytometry . Collectively , these findings demonstrate that knockdown of Nrf2 can enhance the basal level of autophagy in the U251 glioma cell line . Furthermore , after the treatment with TMZ ( 100µM ) for 3 days , the U251-Si-Nrf2 transfected cells showed less viability rate by cell counting kit-8 ( CCK-8 ) assay and the levels of autophagy increased obviously through analysis of western blot and AO staining using flow cytometry . Taken together , our results suggest that knockdown of Nrf2 may enhance autophagy induced by TMZ in the U251 glioma cell line , which should be further evaluated for novel anticancer activity .
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[
0,
0,
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0,
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1,
0,
0
] |
23128449
|
Prostate cancer is the second most common cancer in elderly men worldwide and its incidence rate is rising continuously . Agents capable of inducing apoptosis in prostate cancer cells seem a promising approach to treat this malignancy . In this study we describe the synthesis of a number of novel N- and N,N'-substituted S-2,3,4,5,6-pentabromobenzylisothiouronium bromides and their activity against the human prostate adenocarcinoma PC3 cell line . All the compounds produced changes in mitochondrial transmembrane potential and cell cycle progression , showed a cytostatic effect and induced apoptosis in the tested cancer line in a concentration- and time-dependent manner . The most effective compounds ZKK-3 , ZKK-9 and ZKK-13 produced , at 20 microM concentration , apoptosis in 42 , 46 , and 66% of the cells , respectively , after 48 h incubation . Two selected S-2,3,4,5,6-pentabromobenzylisothiouronium bromides ( ZKK-3 , ZKK-9 ) showed also a synergic proapoptotic effect with the new casein kinase II inhibitor 2-(4-methylpiperazin-1-yl)-4,5,6,7-tetrabromo-1H-benzimidazole ( TBIPIP ) in the PC3 cell line .
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[
0,
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0,
0,
0,
0,
1,
1,
0
] |
23285698
|
BACKGROUND/AIMS We investigated whether the anticancer drug Ukrain ( UK ) is able to modulate the expression of some of the key markers of tumor progression in pancreatic cell carcinoma , in order to assess its potential therapeutic effect . METHODS Three cell lines ( HPAF-II , PL45 , HPAC ) were treated with UK ( 5 , 10 and 20 μM ) for 48 h , or left untreated . Secreted protein acidic and rich in cysteine ( SPARC ) mRNA levels were assessed by real-time PCR . Matrix metalloproteinases ( MMP)-2 and -9 activity was analyzed by SDS zymography ; SPARC protein levels in cell lysates and supernatants were determined by Western blot . Cell cycle was determined by flow cytometric analysis , and invasion by matrigel invasion assay . RESULTS UK down-regulated MMP-2 and MMP-9 , suggesting that UK may decrease pancreatic cancer cell invasion , as confirmed by the matrigel invasion assay . SPARC protein down-regulation in supernatants points to an inhibition by UK of extracellular matrix remodeling in the tumor microenvironment . At the same time , SPARC mRNA and cellular protein level up-regulation suggests that UK can affect cell proliferation by cell cycle inhibition , showing a cell cycle G2/M arrest in UK-treated cells . CONCLUSION Our results suggest that UK modulates two major aspects involved in tumorigenesis of pancreatic cancer cells , such as extracellular matrix remodeling and cell proliferation .
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[
1,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
20975318
|
Purpose of this work was to synthesize several cis-/trans- isomer pairs of the platinum(II) complexes , and study the extent and the mode of their antiproliferative activity on HeLa cells . Six platinum(II) isomer pairs have a general formula cis-/trans-[PtA2X2] , where A is ligand : ammonia ( NH3 ) , pyridine ( Py ) ; and X is ligand : chloride ion ( Cl- ) , bromide ion ( Br- ) , iodide ion ( I- ) , thiocyanato ion ( SCN- ) ; four compounds have different structural formulas , and these are cis-/trans-[Pt(NH2OH)2(NH3)2]Cl2 , and cis-/trans-Pt(Gly)2 , where Gly is bidentate glycinato ligand . Results of the MTT assay , showed that six cis- and one trans-platinum(II) complexes exhibited cytotoxicity ( IC50 ) ranging between 5 and 33 microM . Most of the cis-platinum(II) isomers caused significant alteration of cell cycle phases progression , and induced apoptosis in degree that varied among different compounds , as evaluated using flowcytometry and morphological study . Spectrophotometric analysis ( AAS ) indicated that there is no correlation between intracellular platinum(II) accumulation and cytotoxicity of tested complexes .
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1,
0
] |
12636098
|
BACKGROUND/AIMS Endoscopic mucosal resection and laparoscopic wedge resection have become more common in the treatment of early gastric cancer . However , lymph node metastasis is a major poor prognostic factor influencing tumor recurrence and survival . To predict the risk of lymph node metastasis in early gastric cancer , the authors conducted a study to investigate the clinicopathologic characteristics of early gastric cancer with lymph node metastasis . METHODOLOGY From 1982 to 1998 , 181 patients of early gastric cancer underwent primary surgery and were included in the study . Patient data was postoperatively reviewed regarding age , gender , tumor size , depth of invasion , histologic differentiation , macroscopic classification and anatomic level of lymph node metastasis . The chi 2 test or Student's t test was used for statistical analysis . Logistic regression analysis was used to evaluate the independent risk factors for lymph node metastasis . RESULTS Lymph node metastasis was observed in 19 cases ( 11% ) . Early gastric cancer with size larger than 4 cm ( P < 0.05 ) , with submucosal invasion ( P < 0.01 ) , and with poor differentiation ( P < 0.05 ) was associated with higher risk of lymph node metastasis . The macroscopic classification had no predictive value . Multivariate analysis showed that submucosal invasion correlated best with lymph node spread ( OR 10.25 , 95% CI : 2.10-49.96 ) , followed by tumor size larger than 4 cm ( OR 4.99 , 95% CI : 1.46-17.05 ) , and poorly differentiated histological subtype ( OR 3.31 , 95% CI : 1.16-9.45 ) . CONCLUSIONS Poor differentiation , submucosal invasion and large tumor size were independent risk factors for lymph node metastasis in early gastric cancer . Macroscopic classification was not correlated with lymph node metastasis .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
12239968
|
Systemic oxidative stress is associated with a wide range of pathological conditions . Oxidative DNA damage is frequently measured in circulating lymphocytes . Mitochondrial DNA ( mtDNA ) is known to be more sensitive to oxidative damage than nuclear DNA but is rarely used for direct measurement of DNA damage in clinical studies . Based on the supercoiling-sensitive real-time PCR method , we propose a new approach for the noninvasive monitoring of systemic oxidative stress by quantifying the mtDNA structural damage and copy number change in isolated lymphocytes in a single test . We show that lymphocytes have significantly less mtDNA content and relatively lower baseline levels of damage than cancer cell lines . In an ex vivo challenge experiment , we demonstrate , for the first time , that exogenous H2O2 induces a significant increase in mtDNA damage in lymphocytes from healthy individuals , but no repair activity is observed after 1 h recovery . We further demonstrate that whole blood may serve as a convenient alternative to the isolated lymphocytes in mtDNA analysis . Thus , the blood analysis with the multiple mtDNA end-points proposed in the current study may provide a simple and sensitive test to interrogate the nature and extent of systemic oxidative stress for a broad spectrum of clinical investigations .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
1
] |
23484085
|
Autophagy is one of the survival processes of cancer cells , especially in stressful conditions such as starvation , hypoxia and chemotherapeutic agents . However , its roles in tumor survival have not yet been fully elucidated . Here , we found for the first time that JAK2/STAT3 was activated in HeLa cells when they were starved or treated with rapamycin . STAT3 activation was associated with autophagic processes , because it was completely inhibited by 3-methyladenine , partially inhibited by knockdown of molecules associated with autophagic processes and blocked by antioxidants , DPI , a Nox inhibitor and knockdown of p22 phox , indicating that ROS generated by Nox that was activated during autophagic processes activated JAK2/STAT3 pathway . Activated STAT3 directly bound to IL6 promoter and increased IL6 mRNA and protein secretion . Finally , the conditioned media , which included IL6 , from starved HeLa cells promoted cancer cell survival in both normal and starved conditions , confirmed by clonogenic , proliferation and cell death assays . These data together indicate that the autophagic process in cancer cells can contribute to their survival by JAk2/STAT3 activation and subsequent secretion of growth factors .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
20930550
|
Apoptosis , programmed cell death , was previously shown to be induced by the mAb anti-APO-1 ( IgG3 , kappa ) by binding to the APO-1 cell surface Ag , a new member of the nerve growth factor/TNF receptor superfamily . To investigate the role of the Ig H chain Fc regions we compared induction of apoptosis by the original mAb IgG3 anti-APO-1 with anti-APO-1 F(ab')2 fragments and different anti-APO-1 isotypes ( IgG1 , IgG2b , IgG2a , and IgA ) isolated by sequential sublining . We found that IgG3 was the most active isotype ; IgG1 , IgG2a , and IgA showed intermediate activity , and IgG2b and F(ab')2 were inactive . Cytotoxic activity of the inactive or less active antibody preparations was fully reconstituted by protein A , anti-mouse Ig , or anti-mouse Ig F(ab')2 , respectively . Thus , APO-1-mediated induction of apoptosis was dependent on efficient cross-linking of APO-1 cell surface Ag , indirectly augmented by anti-APO-1 Fc-Fc self-aggregation . Because of their different in vitro activity we selected IgG3- , IgG2b- , and IgA anti-APO-1 to test their antitumor activity against solid human B lymphoblastoid tumors in SCID mice . The isotypes showed a different serum half-life ( IgG3 : 9.2-10.4 days , IgG2b : 1.9-2.6 days , and IgA : 14.1-29.2 h ) and a different initial tumor localization 4 h after i.p. injection ( IgG3 around the blood vessels , IgG2b homogeneously , and IgA heterogeneously distributed in the tumor ) . All antibody preparations induced tumor regression by induction of apoptosis , even IgG2b anti-APO-1 inactive in vitro without cross-linking . The activity of IgA anti-APO-1 , which did not mediate complement-dependent cytotoxicity or antibody-dependent cellular cytotoxicity indicates that apoptosis may be used as the main if not the only mechanism of induction of tumor regression in vivo . As with in vitro , IgG3 anti-APO-1 was the most effective isotype also in vivo . This result suggests that cross-linking of APO-1 on the tumor cell surface may also be required for tumor regression by apoptosis in vivo . Taken together , our data show that selective targeting of apoptosis to tumors may be an efficient antitumor mechanism .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
1431095
|
A metaphase chromosome analysis method was used to evaluate the mutagenic activity of volatile petroleum fractions in chronically intoxicated rats . The findings indicate that chronic inhalation exposure of the rats to volatile petroleum fractions at different concentrations results in a significant ( 2.5-fold ) increase , compared to the spontaneous level , in the occurrence of chromosomal aberrations in the bone marrow cells in a number of generations . In addition to chromosomal structural abnormalities , there are genomic changes ( aneuploidy , polyploidy ) . There is a tendency towards an increased rate of petroleum-induced chromosomal aberrations in a number of generations ( P , F1 , and F2 ) in the rat bone marrow cells . The maximum mutagenic effect of volatile petroleum fractions was found when used at concentrations of 10 and 100 mg/l upon long-term chronic exposure during three generations ( P1 , F1 , and F2 ) . The findings are indicative of the mutagenic activity of volatile petroleum fractions , which is likely to pose a potential risk from environmental pollution to biota and population health in the area of intensive oil extraction and refining .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23082676
|
Epithelial-mesenchymal transition ( EMT ) is a critical process providing tumor cells with the ability to migrate and escape from the primary tumor and metastasize to distant sites . Recently , EMT was shown to be associated with the cancer stem cell ( CSC ) phenotype in breast cancer . Snail is a transcription factor that mediates EMT in a number of tumor types , including colorectal cancer ( CRC ) . Our study was done to determine the role of Snail in mediating EMT and CSC function in CRC . Human CRC specimens were stained for Snail expression , and human CRC cell lines were transduced with a retroviral Snail construct or vector control . Cell proliferation and chemosensitivity to oxaliplatin of the infected cells were determined by the MTT ( colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide ) assay . Migration and invasion were determined in vitro using modified Boyden chamber assays . EMT and putative CSC markers were analyzed using Western blotting . Intravenous injection of tumor cells was done to evaluate their metastatic potential in mice . Snail was overexpressed in human CRC surgical specimens . This overexpression induced EMT and a CSC-like phenotype in human CRC cells and enhanced cell migration and invasion ( P < 0.002 vs. control ) . Snail overexpression also led to an increase in metastasis formation in vivo ( P < 0.002 vs. control ) . Furthermore , the Snail-overexpressing CRC cells were more chemoresistant to oxaliplatin than control cells . Increased Snail expression induces EMT and the CSC-like phenotype in CRC cells , which enhance cancer cell invasion and chemoresistance . Thus , Snail is a potential therapeutic target in metastatic CRC .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23342249
|
Numerous scientific studies have examined the relationship between coffee consumption and an array of medical conditions , including cancer , and yet the direct effect of commercially brewed coffee on cancer cells has not been evaluated . The purpose of this study was to evaluate the antiproliferation effect of 4 different regular and decaffeinated coffee brews and 3 of coffee's bioactive ingredients-caffeine , chlorogenic acids , and caffeic acid-on 2 human ovarian cancer cell lines alone and in combination with cisplatin ( CDDP ) . Antiproliferation IC(50) for Brand A regular and decaffeinated coffee on A2780 cells was 1:70.79 ± 5.66 and 1:55.68 ± 2.00 dilution ( vol/vol ) in tissue culture medium ( mean ± standard error of the mean ; N = 12 ) , respectively , and slightly lower on A2780CP70 cells . Three other brands showed lower antiproliferation activity . Antiproliferation IC(50) concentrations of chlorogenic acids and caffeic acid are many folds lower than caffeine . In combination with CDDP , both Brand A coffee brews , and the 3 bioactive compounds , showed additive antiproliferation effect on both cancer cell lines . Flow cytometry analysis showed that coffee treatment induced apoptosis of A2780 and A2780CP70 cells . To our knowledge , this is the first report showing the antiproliferation activity and the additive effect with CDDP of commercially prepared coffee brews on human cancer cell lines .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
21058192
|
OBJECTIVE To investigate the mutations of epidermal growth factor receptor ( EGFR ) in tumor tissue and pleural effusion in advanced non-small cell lung cancer ( NSCLC ) patients , and to analyze the relationship between EGFR mutations and the clinicopathologic characteristics . METHODS Two-hundred and forty-one cases of formalin-fixed , paraffin-embedded tumor tissues and 14 paired pleural effusions from advanced NSCLC patients were collected . Twenty-nine different EGFR mutations in exons 18-21 were assessed by scorpions and amplification refractory mutation system ( scorpions ARMS ) using real time PCR . The relationship between the EGFR mutations and clinical parameters was analyzed using statistical methods . EGFR mutation of 37 cases were detected with direct sequencing , and assessed the sensitivity , the specificity and the accuracy of scorpions ARMS . RESULTS EGFR somatic mutations were detected in 114 of 234 advanced NSCLC patients , with the mutation rate of 48.7% , including deletions in exon 19 in 65 patients and point mutation of L858R in exon 21 in 39 patients ; both accounting for 91.2% ( 104/114 ) of all types of EGFR mutations . The test results of 14 paired pleural effusion specimens were entirely the same to the tissues . The concordance rate of 2 different detection methods was 94.6% . Mutation rate was higher in women ( 55.9% ) than in men ( 42.2% ) , and there was no difference in mutation rates between smokers and non-smokers ; patients in stage IIIB and stage IV ; adenocarcinoma and non-adenocarcinoma . CONCLUSIONS EGFR somatic mutations appear to occur frequently in Chinese . Scorpions ARMS technology is a sensitive method to detect EGFR mutations and is suitable for screening patients who would likely respond to EGFR inhibitors therapy .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23157744
|
Bulky DNA adducts are considered a potential biomarker of cancer risk . In this study , the association between various lifestyle , environmental , and genetic factors and the levels of bulky DNA adducts in peripheral leukocytes was examined in a study group nested within a population-based prospective Danish cohort . At enrollment , blood samples were collected and information on lifestyle , including dietary and smoking habits , obtained . Previously , bulky DNA adducts were measured in 245 individuals who developed lung cancer and 255 control members of the cohort . Of these 500 individuals , data on 375 individuals were included in this study , excluding 125 cases , which developed lung cancer within the first 3 yr after blood sampling . Bulky DNA adduct levels were measured by 32P-postlabeling technique and polymorphisms in carcinogen metabolism and DNA repair genes were determined . Potential predictors of bulky DNA adduct levels were analyzed by univariate and multivariate regression analyses . Women tended to have higher adduct levels than men . Living in central Copenhagen and surface darkness of fried meat and fish were associated with quantitative higher adduct levels . No significant associations were found between dietary factors or smoking and DNA adduct levels . Further , the results showed no prominent associations between any of 12 genetic polymorphisms and adduct levels . Overall , our study showed only few associations between dietary , environmental , and genetic factors and levels of bulky DNA adducts measured in peripheral leukocytes in a general Danish population .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20391138
|
BACKGROUND Apoptosis-stimulating protein of p53 ( ASPP ) family members can stimulate the apoptotic function of p53 but have no impact on its cell cycle arrest function . MATERIAL AND METHODS The expression pattern of the ASPP family consisting of ASPP1 , ASPP2 , and iASPP was examined by immunohistochemistry in 45 formalin-fixed and paraffin-embedded endometrial endometrioid adenocarcinoma ( EEA ) specimens and 26 normal endometrial tissue ( NET ) samples . RESULTS The expression rates of ASPP1 and ASPP2 in EEA were significantly lower than those in NET ( p < 0.05 ) . However , the iASPP expression rate in EEA was statistically higher in contrast to NET ( p < 0.05 ) . Expression of ASPP1 and iASPP in EEA had no correlation with any clinicopathological features ( p > 0.05). iASPP was associated with grade , invasion , and lymph node metastasis ( p < 0.05 ) . CONCLUSIONS It is a novel finding that the expression pattern of the ASPP family members has respective pathological and clinical implications in EEA , and iASPP might be a candidate target for EEA therapy .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
20926896
|
A cell line designated HUUCLEC was established from a human uterine cervical lymphoepithelial carcinoma obtained from a 61-year-old Japanese woman . The cell line has grown slowly without interruption and serial passages were successively carried out 60 times within 3 years . The cultured cells were spindle or round in shape , showing anaplastic and pleomorphic features , a pavement cell arrangement and multilayering without contact inhibition . The population doubling time of the HUUCLEC line was 72 hours while the chromosomal number varied widely and showed aneuploidy . The modal chromosomal number was stable at the triploid range and marker chromosomes were present ; the Ebstein-Barr virus was absent in the cultured cells .
|
[
0,
0,
0,
0,
1,
1,
0,
0,
0,
0
] |
12227504
|
Although the immunomodulatory effects of many herbs have been extensively studied , research related to possible immunomodulatory effects of various spices is relatively scarce . Here , the potential immunomodulatory effects of black pepper and cardamom are investigated . Our data show that black pepper and cardamom aqueous extracts significantly enhance splenocyte proliferation in a dose-dependent , synergistic fashion . Enzyme-linked immunosorbent assay experiments reveal that black pepper and cardamom significantly enhance and suppress , respectively , T helper ( Th)1 cytokine release by splenocytes . Conversely , Th2 cytokine release by splenocytes is significantly suppressed and enhanced by black pepper and cardamom , respectively . Experimental evidence suggests that black pepper and cardamom extracts exert pro-inflammatory and anti-inflammatory roles , respectively . Consistently , nitric oxide production by macrophages is significantly augmented and reduced by black pepper and cardamom , respectively . Remarkably , it is evident that black pepper and cardamom extracts significantly enhance the cytotoxic activity of natural killer cells , indicating their potential anti-cancer effects . Our findings strongly suggest that black pepper and cardamom exert immunomodulatory roles and antitumor activities , and hence they manifest themselves as natural agents that can promote the maintenance of a healthy immune system . We anticipate that black pepper and cardamom constituents can be used as potential therapeutic tools to regulate inflammatory responses and prevent/attenuate carcinogenesis .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
20210607
|
High-grade gliomas ( HGG ) , are the most common aggressive brain tumours in adults . Inhibitors targeting growth factor signalling pathways in glioma have shown a low clinical response rate . To accurately evaluate response to targeted therapies further in vitro studies are necessary . Growth factor pathway expression using epidermal growth factor receptor ( EGFR ) , mutant EGFR ( EGFRvIII ) , platelet derived growth factor receptor ( PDGFR ) , C-Kit and C-Abl together with phosphatase and tensin homolog ( PTEN ) expression and downstream activation of AKT and phosphorylated ribosomal protein S6 ( P70S6K ) was analysed in 26 primary glioma cultures treated with the tyrosine kinase inhibitors ( TKIs ) erlotinib , gefitinib and imatinib . Response to TKIs was assessed using 50% inhibitory concentrations ( IC(50) ) . Response for each culture was compared with the EGFR/PDGFR immunocytochemical pathway profile using hierarchical cluster analysis ( HCA ) and principal component analysis ( PCA ) . Erlotinib response was not strongly associated with high expression of the growth factor pathway components . PTEN expression did not correlate with response to any of the three TKIs . Increased EGFR expression was associated with gefitinib response ; increased PDGFR-α expression was associated with imatinib response . The results of this in vitro study suggest gefitinib and imatinib may have therapeutic potential in HGG tumours with a corresponding growth factor receptor expression profile .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
22285130
|
BACKGROUND : CD81 is a transmembrane protein that serves as a putative receptor for hepatitis C virus . In addition , CD81 has been suggested to be involved in a broad range of other cellular functions . Its putative implication in tumorigenesis has so far , however , remained largely unexplored . To assess the candidacy of CD81 as a tumor suppressor in gastric cancer development , we investigated its expression and function in a series of primary gastric tumors and gastric tumor-derived cell lines . METHODS : The expression and concomitant methylation status of the CD81 gene and its effect on tumor development and cellular signaling were evaluated . RESULTS : CD81 mRNA levels were found to be low in 16 of 40 ( 40% ) primary tumors and 9 of 14 ( 64.2% ) cell lines , and these low expression levels were found to correlate with the stage and grade of the tumors . Genomic alterations of CD81 were not encountered , whereas its expression could be re-activated in low expressing cells upon 5-aza-dC treatment . Bisulfite DNA sequencing analysis of 10 CpG sites within the 5 ' proximal region of the CD81 gene promoter revealed that the observed transcriptional silencing was tightly associated with aberrant hypermethylation . Subsequent restoration of CD81 expression induced a G(1) cell cycle arrest and apoptosis , whereas siRNA-mediated CD81 down-regulation promoted cell proliferation and attenuated cellular responses to various apoptotic stress stimuli . Also the colony-forming ability of the tumor cells could be inhibited and enhanced through CD81 up- and down-regulation , respectively . CD81 was found to inhibit p38 ( but not ERK , JNK and AKT ) phosphorylation and its growth suppressive effect could be abolished through p38 up- and down-regulation . CONCLUSION : From our data we conclude that epigenetic inactivation of CD81 is a common feature of gastric tumors and that this inactivation may render growth and survival advantages to the tumor cells , at least partially through p38 signaling .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
23264205
|
Osteoblastic bone metastases are the most common metastases produced by human prostate cancers ( PCa ) . Deregulated activity of Wnt growth factors resulting from overexpression of the Wnt inhibitor Dickkopf-1 ( DKK-1 ) is known to contribute to formation of the osteoblastic component of PCa skeletal bone metastases . In this study , we report that DKK-1 knockdown in osteolytic human PCa cells unexpectedly delays the development of both soft tissue and osseous lesions . PCa cells deficient in DKK-1 expression did not increase canonical Wnt signaling in target osteoblast cell lines ; however , DKK-1 knockdown PCa cells exhibited increased expression of the CDK inhibitor p21(CIP1/WAF1) and a 32% increase in G(1) arrest compared with control cells . Ablating p21(CIP1/WAF1) in PCa cells deficient in DKK-1 was sufficient to rescue tumor growth . Collectively , our findings demonstrate that DKK-1 overexpression supports tumor growth in part by restricting expression of p21(CIP1/WAF1) through a mechanism independent of canonical Wnt signaling .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
21098705
|
Earlier studies indicated that density-arrested cancer cells released an unidentified growth inhibitor whose secretion was prevented by overexpression of the lysosomal protease cathepsin D ( cath D ) . In this study , this growth inhibitor was purified by affinity chromatography and identified as the heat shock cognate 70 protein ( hsc70 ) based on its peptide microsequencing and specific antibody recognition . Among intracellular proteins , including other heat shock proteins , only constitutive hsc70 was secreted in response to the high-cell density . Moreover , hsc70 secretion from cancer cells was generated by serum deprivation , whereas its cellular concentration did not change . Prevention of Hsc70 secretion by cath D overexpression was associated with the formation of multilayer cell cultures , thus indicating a loss of contact inhibition . In addition , we showed that supplementing the culture medium with purified hsc70 inhibited cell proliferation in the nanomolar range . Conversely , removal of this extracellular hsc70 from the medium by either retention on ADP-agarose or competition at the Hsc70 binding site restored cell proliferation . Hsc70 appears active in human breast cancer cells and hypersecreted by direct cath D inhibition . These results suggest a new role of this secreted hsc70 chaperone in cell proliferation that might account for the higher tumor growth of cancer cells overexpressing cath D .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
19802014
|
Tumor cells trigger angiogenesis through overexpression of various angiogenic factors including vascular endothelial growth factor ( VEGF ) and angiopoietin 1 ( Ang1 ) . Therefore , inhibition of the expression of both VEGF and Ang1 , the initial step of tumor angiogenesis , is a promising strategy for cancer chemoprevention and therapy . Grape seed proanthocyanidins ( GSPs ) are widely consumed dietary supplements that have antitumor activity . Due to their polymeric structure , GSPs are poorly absorbed along the gastrointestinal tract and can reach the colon at high concentrations , allowing these chemicals to act as chemopreventive agents for colon cancer . In the present study , we found that GSPs inhibited colon tumor-induced angiogenesis and , thus , the growth of colon tumor xenografts on the chick chorioallantoic membranes . The mechanisms of their action were related to inhibiting the expression of both VEGF and Ang1 through scavenging reactive oxygen species . Previous studies have demonstrated that the chemopreventive effects of GSPs on colon cancer are associated with their growth inhibitory and apoptosis-inducing effects . Our results demonstrate another mechanism by which GSPs inhibit colon tumor growth , which will be helpful for developing GSPs as a pharmacologically safe angiopreventive agent against colorectal cancer .
|
[
0,
0,
0,
0,
0,
0,
1,
1,
0,
1
] |
23026853
|
Breast cancer consists in a chronic inflammatory disease with multiple biological and clinical behaviors . Based on high throughput technologies data , this disease is currently classified according to the molecular expression of estrogen ( ER ) , progesterone ( PR ) and human epidermal growth factor ( HER-2 ) receptors . In this study , we defined the inflammatory profile of the main molecular subtypes of breast cancer patients : luminal ( ER and PR positive , HER-2 negative ) , HER-2 enriched ( HER-2 positive ) and triple negative ( ER , PR and HER-2 negative ) . Cytokines panel was assessed by measurement of TNF-α , TGF-β , IL-1 , IL-10 and IL-12 plasmatic levels . Oxidative profile was assessed by determination of lipid peroxidation , total antioxidant capacity of plasma , malondialdehyde levels , carbonyl content and nitric oxide ( NO ) . Clinical data were correlated with inflammatory findings . Our findings demonstrated that patients bearing the luminal subtype displayed high TNF-α , TGF-β and enhanced oxidative stress levels associated with reduced IL-12 . HER-2-enriched group exhibited higher levels of TNF-α , IL-12 and TGF-β associated with enhanced oxidative stress . Triple-negative subtype exhibited the most aggressive profile of disease behavior , with reduction in both TNF-α and TGF-β , with high levels of lipid peroxidation and NO . The clinical importance of our findings lies in the fact that the inflammatory status varies in distinct ways due to molecular subtype of breast cancer , opening potential therapeutic targets to future therapies .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
22618884
|
The activity of DNA methyltransferase 1 ( DNMT1 ) is associated with diverse biological activities , including cell proliferation , senescence and cancer development . Here , we demonstrated that the HMG box-containing protein 1 ( HBP1 ) transcription factor is a new repressor of DNMT1 in a complex mechanism during senescence . The DNMT1 gene contains an HBP1-binding site at position -115 to -134bp from the transcriptional start site . HBP1 repressed the endogenous DNMT1 gene through sequence-specific binding , resulting in both gene-specific ( e.g. p16(INK4) ) and global DNA hypomethylation changes . The HBP1-mediated repression by DNMT1 contributed to replicative and premature senescence , the latter of which could be induced by Ras and HBP1 itself . A detailed investigation unexpectedly revealed that HBP1 has dual and complex transcriptional functions-both of which contribute to premature senescence . HBP1 both repressed the DNMT1 gene and activated the p16 gene in premature senescence . The opposite transcriptional functions proceeded through different DNA sequences and differential protein acetylation . While intricate , the reciprocal partnership between HBP1 and DNMT1 has exceptional importance , since its abrogation compromises senescence and promotes tumorigenesis . Together , our results suggest that the HBP1 transcription factor orchestrates a complex regulation of key genes during cellular senescence with an impact on overall DNA methylation state .
|
[
0,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
23249948
|
We report the formation , detection , quantitation and structural characterization of products resulting from the adduction of deoxynucleosides ( deoxyadenosine , deoxyguanosine , deoxycytidine and 5-methyldeoxycytidine ) to the catechol estrogens ( CE ) of estrone , estradiol-17beta and estradiol-17 alpha . The crude products are obtained in a one-pot synthesis through oxidation of catechols to quinones and subsequent Michael-type reaction with the deoxynucleosides in acidic medium . In all experiments , adducts are detected by electrospray ionization mass spectrometry analysis after HPLC separation ( LC/ESI/MS(n) ) . The two pyrimidines deoxycytidine and 5-methyldeoxycytidine yield only CE adducts to deoxynucleosides , which correspond to stable adducts on DNA . For purines , the results depend on the CE ( 2,3- or 3,4-catechols ) used , the function and configuration on carbon 17 ( ketone for estrone , alcohol for alpha and beta isomers of estradiol ) , and on the purine itself ( deoxyadenosine or deoxyguanosine ) . Both stable adducts and deglycosylated adducts are formed , and therefore formation of stable adducts on DNA as well as the loss of purines from the DNA strands could be possible . MS(2) and MS(3) experiments prove to be relevant for further structural determinations , enabling in some cases the elucidation of the regiochemistry of adduction on the A and B rings of the steroid moiety .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
12441195
|
PURPOSE Radiation therapy appears to kill cells mainly by inducing DNA double-strand breaks . We investigated whether the DNA repair gene expression status might influence the risk of locoregional recurrence ( LRR ) in breast cancer patients . METHODS AND MATERIALS We used a quantitative reverse transcriptase PCR-based approach to measure messenger RNA levels of 20 selected DNA repair genes in tumor samples from 97 breast cancer patients enrolled in a phase III trial ( Centre René Huguenin cohort ) . Normalized mRNA levels were tested for an association with LRR-free survival ( LRR-FS ) and overall survival ( OS ) . The findings were validated in comparison with those of an independent cohort ( Netherlands Cancer Institute ( NKI ) cohort ) . Multivariate analysis encompassing known prognostic factors was used to assess the association between DNA repair gene expression and patient outcome . RESULTS RAD51 was the only gene associated with LRR in both cohorts . With a median follow-up of 126 months in the CRH cohort , the 5-year LRR-FS and OS rates were 100% and 95% in the 61 patients with low RAD51 expression , compared with 70% and 69% in the 36 patients with high RAD51 expression , respectively ( p < 0.001 ) . RAD51 overexpression was associated with a higher risk of LRR ( hazard ratio [ HR ] , 12.83 ; 95% confidence interval [ CI ] , 3.6-45.6 ) and death ( HR , 4.10 ; 95% CI , 1.7-9.7 ) . RAD51 overexpression was also significantly associated with shorter LRR-FS and OS in the NKI cohort . CONCLUSIONS Overexpression of RAD51 , a key component of the homologous DNA repair pathway , is associated with poor breast cancer outcome . This finding warrants prospective studies of RAD51 as a prognosticator and therapeutic target .
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[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20092964
|
We recently isolated an exon-4-deleted epidermal growth factor receptor ( EGFR ) variant , termed de4 EGFR . Because the extracellular domain alteration of receptors often influences the antitumor effect of therapeutic antibodies , it is essential to test the sensitivity of de4 EGFR(+) tumors to anti-EGFR antibodies . Therefore , in this study , the antitumor activities of mAb CH12 , an anti-EGFRvIII antibody developed in our laboratory , as well as a U.S. Food and Drug Administration-approved anti-EGFR antibody , cetuximab ( C225 ) , were characterized on de4 EGFR(+) models . The results of FACS assays showed that CH12 bound to de4 EGFR with a higher avidity than did C225 . Interestingly , CH12 , but not C225 , significantly inhibited the metastasis and growth of U87MG-de4 EGFR xenografts , with a growth-inhibition ratio of 46.48% in vivo , and prolonged the survival of the tumor-bearing mice by 37.2% . Treatment with CH12 significantly suppressed tumor proliferation and angiogenesis with increased tumor apoptosis . Mechanistically , de4 EGFR protein expression was virtually undetectable in the U87MG-de4 EGFR xenografts treated with CH12 . This may account for the observed reduction of Akt and Erk phosphorylation , cyclin D1 , Bcl-2 , and Bcl-x(L) expression and the increase of p27 and E-cadherin expression . Intriguingly , LAMP-1 , a major component of the lysosome , was significantly up-regulated in the CH12-treated group but not in the C225-treated group , suggesting its contribution to the degradation of de4 EGFR . Taken together , our data demonstrated that mAb CH12 is a promising therapeutic agent for treating de4 EGFR(+) gliomas .
|
[
1,
0,
0,
0,
0,
0,
1,
1,
1,
0
] |
21917986
|
The purpose of this study was to evaluate the effects of composite wound dressing films made of silk fibroin ( SF ) containing hydroxyapatite ( HA ) or polarized HA ( pHA ) powders on endothelial cell ( EC ) behaviors that have important roles in the wound-healing process . XRD revealed the SF films to be semicrystalline , with a broad peak centered at about 20.7� which is characteristic of β-sheets embedded within an amorphous matrix . The SF composite films with 0.6 ( w/v)% in concentration of HA powder ( HA/SF ) or pHA powder ( pHA/SF ) contained HA crystals of amorphous and silk II crystalline structures . SEM observation showed that there were differences in SF morphology between HA/SF and pHA/SF . The pHA/SF exhibited a furry texture around the pHA crystals , most likely due to the stored charged and zeta potentials . The HA/SF and pHA/SF films enhanced EC migration compared with that on the SF film . The number of migrated cells on the HA/SF and pHA/SF was times larger than that on the SF . The quantitative analysis of the endothelial morphogenesis indicated that the pHA/SF film enhanced the formation of capillary-like structures compared with SF and HA/SF . Thus , pHA/SF may potentially stimulate and contribute to the enhancement of angiogenesis in the wound-healing process .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22275235
|
Pancreatic adenocarcinoma is an aggressive cancer with a greater than 95% mortality rate and short survival after diagnosis . Chemotherapeutic resistance hinders successful treatment . This resistance is often associated with mutations in codon 12 of the K-Ras gene ( K-Ras 12 ) , which is present in over 90% of all pancreatic adenocarcinomas . Codon 12 mutations maintain Ras in a constitutively active state leading to continuous cellular proliferation . Our study determined if TRAIL resistance in pancreatic adenocarcinomas with K-Ras 12 mutations could be overcome by first sensitizing the cells with Benzyl isothiocyanate ( BITC ) . BITC is a component of cruciferous vegetables and a cell cycle inhibitor . BxPC3 , MiaPaCa2 and Panc-1 human pancreatic adenocarcinoma cell lines were examined for TRAIL resistance . Our studies show BITC induced TRAIL sensitization by dual activation of both the extrinsic and intrinsic apoptotic pathways .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20559452
|
Metastasis is a complex process utilizing both tumor-cell-autonomous properties and host-derived factors , including cellular immunity . We have previously shown that germline polymorphisms can modify tumor cell metastatic capabilities through cell-autonomous mechanisms . However , how metastasis susceptibility genes interact with the tumor stroma is incompletely understood . Here , we employ a complex genetic screen to identify Cadm1 as a novel modifier of metastasis . We demonstrate that Cadm1 can specifically suppress metastasis without affecting primary tumor growth . Unexpectedly , Cadm1 did not alter tumor-cell-autonomous properties such as proliferation or invasion , but required the host's adaptive immune system to affect metastasis . The metastasis-suppressing effect of Cadm1 was lost in mice lacking T cell-mediated immunity , which was partially phenocopied by depleting CD8(+) T cells in immune-competent mice . Our data show a novel function for Cadm1 in suppressing metastasis by sensitizing tumor cells to immune surveillance mechanisms , and this is the first report of a heritable metastasis susceptibility gene engaging tumor non-autonomous factors .
|
[
1,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
23028344
|
The " high-risk " human papillomavirus types 16 ( HPV-16 ) and 18 ( HPV-18 ) have been etiologically implicated in the majority of human cervical carcinomas . In these cancers , the viral DNAs are often integrated into the host genome so that expression of the E1 and the E2 genes is lost , suggesting that disruption of these regulatory genes plays an important role in carcinogenic progression . Previous studies defining the viral genes affecting HPV-16 transformation functions have used the " prototype " viral genome , which was cloned from a human cervical carcinoma and later discovered to harbor a mutation in the E1 gene . In this study , we have corrected this mutation and have evaluated the effect of mutations of either the E1 or the E2 gene on the efficiency of HPV-16 immortalization of human keratinocytes . Mutation of either the E1 gene or the E2 gene in the background of a " wild-type " HPV-16 genome markedly increased immortalization capacity . Mutations were also generated in the E2-binding sites located upstream of the P97 promoter , which directs synthesis of the viral E6 and E7 transforming genes . E2 negatively regulates the P97 promoter through binding at adjacent sites . Surprisingly , the mutation of these sites only partially relieved the negative effect of E2 on viral immortalization , implicating additional mechanisms in the E2 repression of viral immortalization functions . Our results provide genetic evidence that the E1 and E2 gene products each can repress HPV-16 immortalization and support the hypothesis that a selective growth advantage is provided by integration of the viral genome in a manner that causes the loss of expression of either E1 or E2 .
|
[
0,
0,
0,
1,
0,
1,
0,
0,
0,
0
] |
1313584
|
Approximately 10% of the U.S. population ingests <50% of the current recommended daily allowance for zinc . We investigate the effect of zinc deficiency on DNA damage , expression of DNA-repair enzymes , and downstream signaling events in a cell-culture model . Low zinc inhibited cell growth of rat glioma C6 cells and increased oxidative stress . Low intracellular zinc increased DNA single-strand breaks ( comet assay ) . Zinc-deficient C6 cells also exhibited an increase in the expression of the zinc-containing DNA-repair proteins p53 and apurinic endonuclease ( APE ) . Repletion with zinc restored cell growth and reversed DNA damage . APE is a multifunctional protein that not only repairs DNA but also controls DNA-binding activity of many transcription factors that may be involved in cancer progression . The ability of the transcription factors p53 , nuclear factor kappaB , and activator protein 1 ( AP1 ) to bind to consensus DNA sequences was decreased markedly with zinc deficiency , as assayed by electrophoretic mobility-shift assays . Thus , low intracellular zinc status causes oxidative DNA damage and induces DNA-repair protein expression , but binding of p53 and important downstream signals leading to proper DNA repair are lost without zinc .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
1
] |
12481036
|
Hepatocellular carcinoma ( HCC ) is the most common primary malignant tumor that accounts for of all liver cancer cases worldwide . It is a multifactorial disease caused by a variety of risk factors and often develops in the background of underlying cirrhosis . A number of cellular phenomena , such as tumor microenvironment , inflammation , oxidative stress , and hypoxia act in concert with various molecular events to facilitate tumor initiation , progression , and metastasis . The emergence of microRNAs and molecular-targeted therapies adds a new dimension in our efforts to combat this deadly disease . Intense research in this multitude of areas has led to significant progress in our understanding of cellular processes and molecular mechanisms that occur during multistage events that lead to hepatocarcinogenesis . In this review , we discuss the current knowledge of HCC , focusing mainly on advances that have occurred during the past 5years and on the development of novel therapeutics for liver cancer .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23007558
|
OBJECTIVES To investigate the expression of TLR-4 ( toll-like receptor ) on human cervical cancer and find the biological function of the TLR-4 signal system . METHODS The immunohistochemistry method was performed to study the protein expression and distribution of TLR-4 . The viability of HeLa cells was determined by cell viability assay . Cell proliferation was detected by FCM , ELISA and Western blot were used to observe the gene and protein expression of IL-6 and TGF-beta1 in Hela cell lines . RESULTS TLR-4 was over-expressed in cervix cancer , and its activation by LPS promotes proliferation and anti-apoptosis in Hela cells in vitro . Moreover the cell line proliferation increased in a dose- and time-dependent manner . The production of IL-6 and TGF-beta1 were promoted through the activation of the NF-kappaB signaling pathway .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22873102
|
Eukaryotic High-Mobility Group B ( HMGB ) proteins alter DNA elasticity while facilitating transcription , replication and DNA repair . We developed a new single-molecule method to probe non-specific DNA interactions for two HMGB homologs : the human HMGB2 box A domain and yeast Nhp6Ap , along with chimeric mutants replacing neutral N-terminal residues of the HMGB2 protein with cationic sequences from Nhp6Ap . Surprisingly , HMGB proteins constrain DNA winding , and this torsional constraint is released over short timescales . These measurements reveal the microscopic dissociation rates of HMGB from DNA . Separate microscopic and macroscopic ( or local and non-local ) unbinding rates have been previously proposed , but never independently observed . Microscopic dissociation rates for the chimeric mutants ( s(-1) ) are higher than those observed for wild-type proteins ( s(-1) ) , reflecting their reduced ability to bend DNA through short-range interactions , despite their increased DNA-binding affinity . Therefore , transient local HMGB-DNA contacts dominate the DNA-bending mechanism used by these important architectural proteins to increase DNA flexibility .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23143110
|
SET and MYND domain-containing protein 3 ( SMYD3 ) is a histone methyltransferase that plays an important role in transcriptional regulation in human carcinogenesis . It can specifically methylate histone H3 at lysine 4 and activate the transcription of a set of downstream genes , including several oncogenes ( e.g. , N-myc , CrkL , Wnt10b , RIZ and hTERT ) and genes involved in the control of cell cycle ( e.g. , CyclinG1 and CDK2 ) and signal transduction ( e.g. , STAT1 , MAP3K11 and PIK3CB ) . To determine the effects of SMYD3 over-expression on cell proliferation , we transfected SMYD3 into MDA-MB-231 cells and found that these cells showed several transformed phenotypes as demonstrated by colony growth in soft agar . Besides , we show here that down-regulation of SMYD3 could induce G1-phase cell cycle arrest , indicating the potent induction of apoptosis by SMYD3 knockdown . These results suggest the regulatory mechanisms of SMYD3 on the acceleration of cell cycle and facilitate the development of strategies that may inhibit the progression of cell cycle in breast cancer cells .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
0,
0
] |
20957523
|
BACKGROUND Knowledge of gene expression kinetics around neuronal cell birth is required to dissect mechanisms underlying progenitor fate . Here , we timed cell cycle and neuronal protein silencing/induction during cell birth in the developing murine retina . RESULTS The pan-cell cycle markers Pcna and Mcm6 were present in the post-mitotic ganglion cell layer . Although confined to the neuroblastic layer ( NBL ) , 6-7% of Ki67(+) cells lacked six progenitor/cell cycle markers , and expressed neuronal markers . To define protein extinction/induction timing , we defined G2/M length throughout retinogenesis , which was typically 1-2 h , but <10% cells took double this time . BrdU-chase analyses revealed that at E12.5 , Tubb3 ( Tuj1 ) appeared at M-phase , followed by Calb2 and Dcx at h , Elavl2/3/4 at h , and Map2 at h after cell birth , and these times extended with embryonic age . Strikingly , Ki67 was not extinguished until up to a day after cell cycle exit , coinciding with exit from the NBL and induction of late markers such as Map1b/Uchl1/Rbfox3 . CONCLUSIONS A minor population of progenitors transits slowly through G2/M and , most importantly , some cell cycle proteins are retained for an unexpectedly long period in post-mitotic neurons . The high-resolution map of cell birth kinetics reported here provides a framework to better define mechanisms that regulate neurogenesis .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22837015
|
BACKGROUND Phosphorylation of the H2AX histone is an early indicator of DNA double-strand breaks and of the resulting DNA damage response . In the present study , we assessed the expression and prognostic significance of \u03b3-H2AX in a cohort of 96 patients with operable non-small cell lung carcinoma . METHODS Ninety-six paraffin-embedded specimens of non-small cell lung cancer patients were examined . All patients underwent radical thoracic surgery of primary tumor ( lobectomy or pneumonectomy ) and regional lymph node dissection. \u03b3-H2AX expression was assessed by standard immunohistochemistry . Follow-up was available for all patients ; mean duration of follow-up was 27.50 ± 14.07 months ( range 0.2-57 months , median 24 months ) . RESULTS Sixty-three patients ( 65.2% ) died during the follow-up period . The mean survival time was 32.2 ± 1.9 months ( 95% confidence interval [ CI ] : 28.5-35.8 months ; median 30.0 months ) ; 1- , 2- and 3-year survival rates were 86.5% ± 3.5% , 57.3% ± 5.1% , and 37.1% ± 5.4% , respectively . Low \u03b3-H2AX expression was associated with a significantly better survival as compared with those having high \u03b3-H2AX expression ( 35.3 months for low \u03b3-H2AX expression versus 23.2 months for high \u03b3-H2AX expression , P = 0.009 ; hazard ratio [ HR ] 1.95 , 95% CI : 1.15-3.30 ) . Further investigation with multivariate Cox proportional hazards regression analysis revealed that high expression of \u03b3-H2AX remained an independent prognostic factor of shorter overall survival ( HR 2.15 , 95% CI : 1.22-3.79 , P = 0.026 ) . A combined p53/\u03b3-H2AX analysis was performed , and we found that the p53 low/\u03b3-H2AX low phenotype was associated with significantly better survival compared with all other phenotypes . CONCLUSION Our study is the first to demonstrate that expression of \u03b3-H2AX detected by immunohistochemistry may represent an independent prognostic indicator of overall survival in patients with non-small cell lung cancer . Further studies are needed to confirm our results .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23180966
|
Metastatic cancer cells typically fail to halt migration on contact with non-cancer cells . This invasiveness is in contrast to normal mesenchymal cells that retract on contact with another cell . Why cancer cells are defective in contact inhibition of locomotion is not understood . Here , we analyse the dynamics of prostate cancer cell lines co-cultured with fibroblasts , and demonstrate that a combinatorial code of Eph receptor activation dictates whether cell migration will be contact inhibited . The unimpeded migration of metastatic PC-3 cells towards fibroblasts is dependent on activation of EphB3 and EphB4 by ephrin-B2 , which we show activates Cdc42 and cell migration . Knockdown of EphB3 and EphB4 restores contact inhibition of locomotion to PC-3 cells . Conversely , homotypic collisions between two cancer cells results in contact inhibition of locomotion , mediated by EphA-Rho-Rho kinase ( ROCK ) signalling . Thus , the migration of cancer cells can switch from restrained to invasive , depending on the Eph-receptor profile of the cancer cell and the reciprocal ephrin ligands expressed by neighbouring cells .
|
[
1,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
21076414
|
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