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Hypoxic events frequently occur in the aquatic environment in association with micro pollutants , including heavy metals . Only a few studies are however available on the uptake and biological responses of heavy metals under hypoxic conditions . To elucidate the phenomenon , mirror carp Cyprinus carpio L . ( 16.13-16.22 g ) were exposed chronically to dietary copper ( Cu ; 250 and 500 mg kg dry wt.(-1) ) for 30 d under normoxic ( 8.25 mg O(2) L(-1) ) and hypoxic ( mg O(2) L(-1) ) conditions and adopting an integrated approach , sub-lethal biomarker responses were determined at different levels of biological organisation . Level of oxidative DNA damage ( as determined by modified Comet assay ) showed strong significant difference following exposure to dietary Cu level under normoxic ( 1.6-fold ) as well as under hypoxic condition at both Cu levels ( 2.1 and 2.5-folds respectively ) . Significant difference was also observed for haematological parameters ( i.e. increased red and white blood cells , haematocrit value and haemoglobin concentration ) . Quantitative histology revealed alterations in tissues ( i.e. liver and gills ) for hypoxic and all dietary Cu treatment groups under both normoxic and hypoxic conditions suggesting a compensatory response to these organs ( p<0.05 ) . The order of Cu accumulation in tissues ( as determined by ICP-OES ) was liver>intestine>kidney>gill . Interestingly , SGR under both normoxic and hypoxic conditions reduced with elevating Cu levels ( p=0.019 ) . Overall , the results provide evidence for enhanced toxicological responses in fish following exposure to Cu either alone or in combination with hypoxic condition and lends support to the evolving viewpoint that many water quality guidelines should be revisited in terms of new ecotoxicological criteria .
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22239943
|
A 51-year-old previously healthy man , an ex-smoker , was admitted to the authors ' medical department with a 3-month history of dry cough ; intermittent fever ; painless , ulcerated cutaneous lesions over the trunk and limbs ( Figure 1 ) ; and progressive weight loss . He was of Greek descent . His medical history was remarkable for nasal polyps , which were surgically removed 15 years earlier . Initially , he had been treated with antibiotics , without improvement . Several days before admission , chest radiography revealed pulmonary infiltrates in the left lower lobe . On admission , physical examination revealed a well-orientated man in mild distress , with inspiratory rhonchi at the lower part of the left lung and scattered erythematous nodules of variable size , some of which were ulcerated . Laboratory values were notable for leukopenia , 3.3 x 10(9)/L ; total protein , 5.9 g/dL ; globulin , 2.2 g/dL ; serum glutamic oxaloacetic transaminase , 86 IU/L ; serum glutamic pyruvic transaminase , 71 IU/L ; and lactate dehydrogenase , 519 U/L . Computed tomograph ( CT ) of the chest showed multiple alveolar opacities bilaterally ( Figure 2 ) . Fiberoptic bronchoscopy did not reveal any important pathologic findings . Results of bronchial biopsy , cytology of bronchoalveolar lavage , washing , brushing , and sputum following bronchoscopy were negative . CT of the brai and sinonasal area revealed an abnormal low-density mass in the left nasal area . CT findings of the abdomen were negative , as were results of a bone marrow biopsy . There was no evidence of immunosuppression . The differential diagnosis , considering the evidence described , included granulomatous or infectious diseases , angiocentric lymphoproliferative lesions , and lymphomas . Biopsy of a skin lesion showed lymphoproliferative infiltration of the dermis with a follicular and angiocentric growth pattern and regional epidermal necrosis . Immunohistochemical stains showed that the tumor cell were positive for CD56 and CD3 ( cytoplasmic positivity ) and expressed the cytotoxic proteins T-cell intracellular antigen and granzyme B ( Figure 3 ) They lacked TdT , CD34 , CD7 , CD8 , TCL-1 , and CD123 . Findings from an in situ hybridization study for Epstein-Barr virus were negative . Give this result , molecular analysis ofT-cell receptor ( TCR ) gene rearrangements was performed using polymerase chain reaction-based TCR-gamma gene , wit negative results . The morphology and the immunophenotype were consistent with natural killer/T-cell lymphoma , nasal-type . Nasal involvement must be first excluded to proceed to the diagnosis of nasal-type natural killer-cell lymphoma . Indeed , histologic examination of the nasal mass revealed its polypoid nature . Thus , the authors were led to the diagnosis of extranodal extranasal natural killer/T-cell lymphoma , nasal-type , CD56-positive , Ep stein-Barr virus-negative , TCR-negative . The patient received combination chemotherapy and completed 4 cycles of cyclophosphamide , doxorubicin vincristine , and prednisone every 14 days for 2 months . Skin lesions improved , and there was no fever soon after the initiation of therapy . Reevaluatio after the fourth cycle , however , disclosed pulmonary infiltrations as well as leukemic infiltration of the central nervous system . The patient had receive systemic salvage chemotherapy and intrathecal infusions of methotrexate . Although the lung lesions had diminished at that time , the patient develope paraplegia , his clinical course rapidly deteriorated , and he eventually died .
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20839428
|
MicroRNAs ( miRs ) are small non-coding RNAs that recently emerged as potent regulators of gene expression . The members of the miR-17-92 cluster have been shown to control endothelial cell functions and neovascularization ; however , the regulation and function of the cluster in endothelial cell lineage commitment has not been explored . This project aimed to test the role of the miR-17-92 cluster during endothelial differentiation . We demonstrate that miR-17 , miR-18 , miR-19 and miR-20 are increased upon the induction of endothelial cell differentiation of murine embryonic stem cells or induced pluripotent stem cells . In contrast , miR-92a and the primary miR-17-92 transcript were downregulated . The inhibition of each individual miR of the cluster by cholesterol-modified antagomirs did not affect endothelial marker gene expression . Moreover , the combination of all antagomirs had no effect . These findings illustrate that although the miR-17-92 cluster regulates vascular integrity and angiogenesis , none of the members has a significant impact on the endothelial differentiation of pluripotent stem cells .
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22797777
|
The solution structure of the complex of enzyme IIA of the N,N'-diacetylchitobiose ( Chb ) transporter with the histidine phosphocarrier protein HPr has been solved by NMR . The IIA(Chb)-HPr complex completes the structure elucidation of representative cytoplasmic complexes for all four sugar branches of the bacterial phosphoryl transfer system ( PTS ) . The active site His-89 of IIA(Chb) was mutated to Glu to mimic the phosphorylated state . IIA(Chb)(H89E) and HPr form a weak complex with a K(D) of mM . The interacting binding surfaces , concave for IIA(Chb) and convex for HPr , complement each other in terms of shape , residue type , and charge distribution , with predominantly hydrophobic residues , interspersed by some uncharged polar residues , located centrally , and polar and charged residues at the periphery . The active site histidine of HPr , His-15 , is buried within the active site cleft of IIA(Chb) formed at the interface of two adjacent subunits of the IIA(Chb) trimer , thereby coming into close proximity with the active site residue , H89E , of IIA(Chb) . A His89-P-His-15 pentacoordinate phosphoryl transition state can readily be modeled without necessitating any significant conformational changes , thereby facilitating rapid phosphoryl transfer . Comparison of the IIA(Chb)-HPr complex with the IIA(Chb)-IIB(Chb) complex , as well as with other cytoplasmic complexes of the PTS , highlights a unifying mechanism for recognition of structurally diverse partners . This involves generating similar binding surfaces from entirely different underlying structural elements , large interaction surfaces coupled with extensive redundancy , and side chain conformational plasticity to optimize diverse sets of intermolecular interactions .
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22593574
|
Immunosuppression of humoral and cellular responses following chronic oral exposure to 1 , 5 , 10 , and 20 ppm N-nitrosodimethylamine ( NDMA ) was examined in CD-1 mice . Monitoring of cumulative mortality and the incidence of peritoneal ascites in animals showed an NDMA dose-related mortality and hepatotoxicity . No visible changes in immunological parameters were noted at the 1 ppm NDMA dose . Immunosuppression of immunoglobulin M ( IgM ) antibody response by NDMA to sheep red blood cells ( SRBC ) was time-related , dose-related , and could be reversed within 30 d by removal of the chemical from the drinking water . Cellular immune response , monitored by allogeneic stimulation of cells in mixed lymphocyte reaction ( MLR ) , was markedly suppressed by 10 and 20 ppm NDMA . Thus , chronic exposure to NDMA , except for the low-hepatotoxic doses of nitrosamine , resulted in a marked and persistent immunosuppression of cellular and humoral responses in CD-1 mice . In conclusion , chronic exposure to the hepatotoxic ( ascite-inducing ) doses of NDMA suppressed humoral and cellular immunity . The persistent immunosuppression could be reversed after the removal of NDMA from the drinking water . Although no direct NDMA-related cancer was reported in humans , our data point to a potential epigenetic carcinogenicity of nitrosamines due to chronic immunosuppression .
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1433375
|
AIMS Tumour cell growth results from a disturbance in the balance between the rate of proliferation and cell death . In this study , proteins involved in the regulation of cell cycle arrest and apoptosis were studied as possible factors responsible for uncontrolled cell growth in colorectal cancer . METHODS The expression of proteins involved in these processes was investigated in 48 metastases from patients with colorectal cancer and compared with eight normal colon mucosa samples and 14 primary tumours . Both primary tumours and metastases were obtained from eight patients . The expression of thymidylate synthase ( TS ) , p53 , retinoblastoma protein ( Rb ) , Fas receptor , Fas ligand , bcl-2 , mcl-1 , bax , and bcl-x was measured using immunohistochemistry . Proliferation was determined by Ki67 staining , whereas apoptosis was assessed by M30 immunostaining , which recognises cleaved cytokeratin 18 . RESULTS In the limited number of cases in which paired comparisons were possible , the expression of TS and Ki67 was significantly higher in metastases than in the matched primary tumour samples ( p = 0.014 and 0.016 , respectively ) , whereas Rb expression was lower in metastases than in primary tumours ( p = 0.024 ) . Fas receptor expression was high in normal mucosa but absent in primary tumours and metastases , whereas the opposite was seen for p53 . The expression of bax , mcl-1 , and bcl-x in normal mucosa was more apical than that seen in malignant cells , where a more diffuse expression pattern was seen ( p < 0.04 ) . Apoptosis was more abundant in primary tumours than in metastases . CONCLUSIONS These results demonstrate that proliferation and apoptosis are disturbed during colorectal cancer progression , and this is accompanied by loss of Rb and Fas expression , the accumulation of p53 and TS , and changes in the expression patterns of bax , mcl-1 , and bcl-xl .
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11896073
|
The radioprotective effects of dimethyl sulfoxide ( DMSO ) have been known for many years , and the suppression of hydroxyl ( OH ) radicals induced by ionizing radiation has been thought to be the main cause of this effect . However , the DMSO concentration used was very high , and might be toxic , in earlier studies . In the present study , we administered a lower , non-toxic concentration ( 0.5% , i.e. , 64 mM ) of DMSO before irradiation and examined its radioprotective effects . Colony formation assay and micronucleus assay showed significant radioprotective effects in CHO , but not in xrs5 , which is defective in the repair function of DNA double-strand breaks . The levels of phosphorylated H2AX and the formation of 53BP1 foci 15 minutes after irradiation , which might reflect initial DNA double-strand breaks , in DMSO-treated CHO cells were similar to those in non-treated cells , suggesting that the radioprotective effects were not attributable to the suppression of general indirect action in the lower concentration of DMSO . On the other hand , 2 hours after irradiation , the average number of 53BP1 foci , which might reflect residual DNA double-strand breaks , was significantly decreased in DMSO-treated CHO cells compared to non-treated cells . The results indicated that low concentration of DMSO exerts radioprotective effects through the facilitation of DNA double-strand break repair rather than through the suppression of indirect action .
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21116101
|
Androgens regulate both the physiological development of the prostate and the pathology of prostatic diseases . However , the mechanisms by which androgens exert their regulatory activities on these processes are poorly understood . In this study , we have determined that androgens regulate overall cell metabolism and cell growth , in part , by increasing autophagy in prostate cancer cells . Importantly , inhibition of autophagy using either pharmacological or molecular inhibitors significantly abrogated androgen-induced prostate cancer cell growth . Mechanistically , androgen-mediated autophagy appears to promote cell growth by augmenting intracellular lipid accumulation , an effect previously demonstrated to be necessary for prostate cancer cell growth . Further , autophagy and subsequent cell growth is potentiated , in part , by androgen-mediated increases in reactive oxygen species . These findings demonstrate a role for increased fat metabolism and autophagy in prostatic neoplasias and highlight the potential of targeting underexplored metabolic pathways for the development of novel therapeutics .
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23250485
|
Cis-diamminedichloroplatinum ( II ) ( cisplatin ) is a well characterized antitumor drug used for the treatment of a variety of human cancers . The cytotoxicity of cisplatin is mainly mediated through the formation of DNA adducts , which are also believed to be responsible for the secondary malignancies produced by the drug . The aim of this study was to determine the in vivo mutagenic activity of cisplatin in the lacZ plasmid-based transgenic mouse model . The mutant frequency ( MF ) and the spectrum of mutations induced by cisplatin in the mouse liver were analyzed and compared to controls . The mean MF in the lacZ gene was increased 2-fold in mice treated with a single 6 mg/kg body weight dose of cisplatin and sacrificed after 17 and 28 days ( P = 0.001 and P < 0.0001 ) . Restriction analysis and sequencing of mutant DNA showed that cisplatin was able to induce both large deletions and point mutations . A specific profile of base substitution and frameshift mutations was identified in treated mice , consisting primarily of G:C-->A:T transitions at GpG and ApG sites , the preferential DNA binding sites of cisplatin , and single basepair deletions/insertions . The present results provide the first evidence that cisplatin has mutagenic activity in vivo and induces a characteristic pattern of mutations in the mouse liver . This mutagenicity may be responsible for its tumorigenic activity .
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12489119
|
A prominent feature of inflammatory diseases is endothelial dysfunction . Factors associated with endothelial dysfunction include proinflammatory cytokines , adhesion molecules , and matrix degrading enzymes . At the transcriptional level , they are regulated by the histone deacetylase sirtuin ( SIRT ) 1 via its actions on the proinflammatory transcription factor nuclear factor-κB ( NF-κB ) . The role of SIRT6 , also a histone deacetylase , in regulating inflammation in endothelial cells is not known . The aim of this study was to determine the effect of SIRT6 knockdown on inflammatory markers in human umbilical vein endothelial cells ( HUVECs ) in the presence of lipopolysaccharide ( LPS ) . LPS decreased expression of SIRT6 in HUVECs . Knockdown of SIRT6 increased the expression of proinflammatory cytokines ( IL-1β , IL-6 , IL-8 ) , COX-prostaglandin system , ECM remodelling enzymes ( MMP-2 , MMP-9 and PAI-1 ) , the adhesion molecule ICAM-1 , and proangiogenic growth factors VEGF and FGF-2 ; cell migration ; cell adhesion to leukocytes . Loss of SIRT6 increased the expression of NF-κB , whereas overexpression of SIRT6 was associated with decreased NF-κB transcriptional activity . Taken together , these results demonstrate that the loss of SIRT6 in endothelial cells is associated with upregulation of genes involved in inflammation , vascular remodelling , and angiogenesis . SIRT6 may be a potential pharmacological target for inflammatory vascular diseases .
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23132960
|
MicroRNAs ( miRNAs ) are small noncoding RNAs , 19-24 nucleotides in length , that regulate gene expression and are expressed aberrantly in most types of cancer . MiRNAs also have been detected in the blood of cancer patients and can serve as circulating biomarkers . It has been shown that secreted miRNAs within exosomes can be transferred from cell to cell and can regulate gene expression in the receiving cells by canonical binding to their target messenger RNAs . Here we show that tumor-secreted miR-21 and miR-29a also can function by another mechanism , by binding as ligands to receptors of the Toll-like receptor ( TLR ) family , murine TLR7 and human TLR8 , in immune cells , triggering a TLR-mediated prometastatic inflammatory response that ultimately may lead to tumor growth and metastasis . Thus , by acting as paracrine agonists of TLRs , secreted miRNAs are key regulators of the tumor microenvironment . This mechanism of action of miRNAs is implicated in tumor-immune system communication and is important in tumor growth and spread , thus representing a possible target for cancer treatment .
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22753494
|
The aim of the present study was to isolate endothelial cells from tooth buds ( unerupted deciduous teeth ) of miniature swine . Mandibular molar tooth buds harvested from swine fetuses at fetal days90-110 were cultured in growth medium supplemented with 15% fetal bovine serum in 100-mm culture dishes until the primary cells outgrown from the tooth buds reached confluence . A morphologically defined set of pavement-shaped primary cells were picked up manually with filter paper containing trypsin/ethylenediamine tetraacetic acid solution and transferred to a separate dish . A characterization of the cellular characteristics and a functional analysis of the cultured cells at passages 3 to 5 were performed using immunofluorescence , a reverse transcriptase polymerase chain reaction assay , a tube formation assay , and transmission electron microscopy . The isolated cells grew in a pavement arrangement and showed the characteristics of contact inhibition upon reaching confluence . The population doubling time was at passage 3 . As shown by immunocytostaining and western blotting with specific antibodies , the cells produced the endothelial marker proteins such as vascular endothelial cadherin , von Willebrand factor , and vascular endothelial growth factor receptor-2 . Observation with time-lapse images showed that small groups of cells aggregated and adhered to each other to form tube-like structures . Moreover , as revealed through transmission electron microscopy , these adherent cells had formed junctional complexes . These endothelial cells from the tooth buds of miniature swine are available as cell lines for studies on tube formation and use in regenerative medical science .
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23435856
|
Glioma tumors are refractory to conventional treatment . Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans . In this study , we introduce oxidative stress-energy depletion ( OSED ) therapy as a new suggested treatment for glioblastoma . OSED utilizes D-amino acid oxidase ( DAO ) , which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide ( H2O2 ) . OSED combines DAO with 3-bromopyruvate ( 3BP ) , a hexokinase II ( HK II ) inhibitor that interferes with Warburg effect , a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis . Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action . C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation , clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes . DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley ( SD ) rats , especially after combination with 3BP . OSED treatment was safe and tolerable in SD rats . OSED therapy may be a promising therapeutic modality for glioma .
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21921941
|
Solar ultraviolet radiation is considered to be injurious rather than necessary for most organisms living on the earth . It is reported that the risk of skin cancer in humans increases by the depletion of the ozone layer . We have examined the genotoxicity of solar ultraviolet , especially the longer wavelength light , using Drosophila . Recently , we have demonstrated that light of wavelength up to 340 nm is mutagenic on Drosophila larvae . Using an excision repair-deficient Drosophila strain ( mus201 ) , we have obtained results suggesting that the lesion caused in larvae by the 320 nm-light irradiation may be similar to the damage induced by irradiation at 310 nm , and that light of 330 and 340 nm may induce damage different from that induced by 310 and 320 nm-light . To examine the difference in DNA damage induced by light of a particular wavelength , we performed monochromatic irradiation on larvae of two Drosophila strains ; one excision repair-deficient ( mei-9 ) and another postreplication repair-deficient ( mei-41). 310 and 320 nm-light was more mutagenic in the mei-9 strain than in mei-41 , whereas 330 and 340 nm-light was more mutagenic in mei-41 than in mei-9 . It is demonstrated that the mei-41 gene is a homologue of the human atm gene which is responsible for a cell cycle checkpoint . This result suggests that 310-320 nm-light induces DNA damage that is subject to nucleotide excision repair ( NER ) and that 330-360 nm-light causes damage to be recognized by the cell cycle checkpoint but it is not repairable by NER .
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12659514
|
Genetic immunotherapy with tumor antigen gene-modified dendritic cells ( DC ) generates robust immunity , although antitumor protection is not complete in all models . Previous experience in a model in which C57BL/6 mice immunized with DC transduced with adenoviral vectors expressing MART-1 demonstrated a 20-40% complete protection to a tumor challenge with B16 melanoma cells . Tumors that did develop in immunized mice had slower growth kinetics compared to tumors implanted in na�ve mice . In the present study , we wished to determine if the supraphysiological production of the Th1-skewing cytokine interleukin-12 ( IL-12 ) could enhance immune activation and antitumor protection in this model . In a series of experiments immunizing mice with DC cotransduced with MART-1 and IL-12 , antitumor protection and antigen-specific splenocyte cytotoxicity and interferon gamma production inversely correlated with the amount of IL-12 produced by DC . This adverse effect of IL-12 could not be explained by a direct cytotoxic effect of natural killer cells directed towards DC , nor the production of nitric oxide leading to down-regulation of the immune response - the two mechanisms previously recognized to explain immune-suppressive effects of IL-12-based vaccine therapy . In conclusion , in this animal model , IL-12 production by gene-modified DC leads to a cytokine-induced dose-dependent inhibition of antigen-specific antitumor protection .
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12386826
|
Recently , the use of gold nanoparticles as potential tumor selective radiosensitizers has been proposed as a breakthrough in radiotherapy . Experiments in living cells and in vivo have demonstrated the efficiency of the metal nanoparticles when combined with low energy x-ray radiations ( below conventional 1 MeV Linac radiation ) . Further studies on DNA have been performed in order to better understand the fundamental processes of sensitization and to further improve the method . In this work , we propose a new strategy based on the combination of platinum nanoparticles with irradiation by fast ions effectively used in hadron therapy . It is observed in particular that nanoparticles enhance strongly lethal damage in DNA , with an efficiency factor close to 2 for double strand breaks . In order to disentangle the effect of the nano-design architecture , a comparison with the effects of dispersed metal atoms at the same concentration has been performed . It is thus shown that the sensitization in nanoparticles is enhanced due to auto-amplified electronic cascades inside the nanoparticles , which reinforces the energy deposition in the close vicinity of the metal . Finally , the combination of fast ion radiation ( hadron therapy ) with platinum nanoparticles should strongly improve cancer therapy protocols .
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20101074
|
Over the past two decades , bioactive natural compounds have been shown to be a plausible adjunct to the treatment of breast cancer , the second leading cause of cancer death among American women . This study was designed to investigate the effects of ursolic acid ( UA ) , a pentacyclic triterpene found in many foods and herbs , in a model of postmenopausal breast cancer . Ovariectomized C57BL/6 mice ( n = 40 ) were randomized to receive control diet ( AIN-93G ) or diet supplemented with UA at 1 of 3 doses ( wt/wt ) : 0.05% , 0.10% , or 0.25% ( ≈54 , 106 , or 266 mg/kg body weight/day , respectively ) . After 3 wk , syngeneic MMTV-Wnt-1 mammary tumor cells were injected in the mammary fat pad , and mice continued on their respective diets for 5 more wk . All UA doses decreased tumor cell proliferation , as assessed by Ki67 immunostaining ; nevertheless , UA at 0.10% was most effective in inhibiting tumor take and decreasing tumor final tumor size . Modulation of Akt/mTOR signaling and induction of apoptosis appeared to mediate these effects on tumor growth . UA potently disrupted cell cycle progression and induced necrosis in a clonal MMTV-Wnt-1 mammary tumor cell line in vitro . This study supports the potential of UA as an antitumorigenic agent .
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21058195
|
BACKGROUND : The immune system has been shown to play an important role in gastrointestinal stromal tumor ( GIST ) . The neutrophil-to-lymphocyte ratio ( NLR ) in blood is an easily assessable parameter of systemic inflammatory response . The aim of this study was to determine whether the NLR is prognostic in GIST . METHODS : A total of 339 previously untreated patients with primary , localized GIST operated at our institution between 1995 and 2010 were identified from a prospectively collected sarcoma database . NLR was assessed preoperatively . Patients who received adjuvant imatinib treatment were excluded from the analysis ( n=64 ) . Cox regression models were calculated and correlation analyses were performed . RESULTS : On univariate analysis , NLR was associated with recurrence-free survival ( RFS ) ( P=0.003 , hazard ratio 3.3 , 95% confidence interval 1.5-7.4 ) . Patients with a low NLR had a 1- and 5-year RFS of 98 and 91% , compared with 89 and 76% in those with a high NLR . The median RFS was not reached . Positive correlations were found between NLR and mitotic rate ( Pearson correlation coefficient [ r]=0.15 , P=0.03 ) , and NLR and tumor size ( r=0.36 , P=0.0001 ) . RFS in patients with a GIST>5cm with low NLR was significantly longer compared to patients with high NLR ( P=0.002 ) . Flow cytometry analysis of freshly obtained GISTs revealed that neutrophils constituted a minimal percentage of intratumoral immune cells . CONCLUSIONS : NLR is a surrogate for high-risk tumor features . Elevated blood NLR appears to represent systemic inflammation in patients with high-risk GIST .
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23054118
|
A fully intact immune system would be expected to hinder the efficacy of oncolytic virotherapy by inhibiting viral replication . Simultaneously , however , it may also enhance antitumor therapy through initiation of proinflammatory , antiviral cytokine responses at the tumor site . The aim of this study was to investigate the role of a fully intact immune system on the antitumor efficacy of an oncolytic virus . In this respect , injection of oncolytic vesicular stomatitis virus ( VSV ) into subcutaneous B16ova melanomas in C57Bl/6 mice leads to tumor regression , but it is not associated with viral replicative burst in the tumor . In contrast , intratumoral delivery of VSV induces an acute proinflammatory reaction , which quickly resolves concomitantly with virus clearance . Consistent with the hypothesis that therapy may not be dependent on the ability of VSV to undergo progressive rounds of replication , a single-cycle VSV is equally effective as a fully replication-competent VSV , whereas inactivated viruses do not generate therapy . Even though therapy is dependent on host CD8+ and natural killer cells , these effects are not associated with interferon-gamma-dependent responses against either the virus or tumor . There is , however , a strong correlation between viral gene expression , induction of proinflammatory reaction in the tumor and in vivo therapy . Overall , our results suggest that acute innate antiviral immune response , which rapidly clears VSV from B16ova tumors , is associated with the therapy observed in this model . Therefore , the antiviral immune response to an oncolytic virus mediates an intricate balance between safety , restriction of oncolysis and , potentially , significant immune-mediated antitumor therapy .
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20016540
|
Liver cancer ranks as the fifth most prevalent malignancy of all cancers worldwide . According to the principles of traditional Chinese medicine , liver Yin deficiency is a common clinical syndrome of liver cancer , and tonifying liver Yin is a common treatment method for liver cancer . However , no hepatocarcinoma-specific liver Yin tonifying formula has yet been established . In the present study , we established a liver cancer-specific combination of herbs , which we term liver Yin tonifying formula ( LYTF ) . We found that LYTF inhibits the proliferation of Bel-7402 cells in a dose- and time-dependent manner . LYTF induces apoptosis in Bel-7402 cells , which is accompanied by activation of caspases-8 , -9 and -3 . Pan-caspase blocking completely abrogates LYTF-induced apoptosis and partially abrogates LYTF-induced proliferation inhibition . LYTF also induces cell senescence , as indicated by a large and flattened morphology , senescence-activated β-galactosidase-positive staining and G0/G1 cell cycle arrest , accompanied by the up-regulation of p16 and p21 and the down-regulation of retinoblastoma protein phosphorylation . These findings suggest that LYTF is effective in inhibiting the growth and survival of hepatocarcinoma cells through the induction of apoptosis and cell senescence . Our study also provides insight into traditional Chinese medicine methods used for the treatment of liver cancer .
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22969849
|
We have recently proposed a new model of cancer metabolism to explain the role of aerobic glycolysis and L-lactate production in fueling tumor growth and metastasis . In this model , cancer cells secrete hydrogen peroxide ( H2O2 ) , initiating oxidative stress and aerobic glycolysis in the tumor stroma . This , in turn , drives L-lactate secretion from cancer-associated fibroblasts . Secreted L-lactate then fuels oxidative mitochondrial metabolism ( OXPHOS ) in epithelial cancer cells , by acting as a paracrine onco-metabolite . We have previously termed this type of two-compartment tumor metabolism the " Reverse Warburg Effect, " as aerobic glycolysis takes place in stromal fibroblasts , rather than epithelial cancer cells . Here , we used MCT4 immuno-staining of human breast cancer tissue microarrays ( TMAs ; > 180 triple-negative patients ) to directly assess the prognostic value of the " Reverse Warburg Effect. " MCT4 expression is a functional marker of hypoxia , oxidative stress , aerobic glycolysis , and L-lactate efflux . Remarkably , high stromal MCT4 levels ( score = 2 ) were specifically associated with decreased overall survival ( < 18% survival at 10 y post-diagnosis ) . In contrast , patients with absent stromal MCT4 expression ( score = 0 ) , had 10-y survival rates of ( p-value < 10 ( -32 ) ) . High stromal levels of MCT4 were strictly correlated with a loss of stromal Cav-1 ( p-value < 10 ( -14 ) ) , a known marker of early tumor recurrence and metastasis . In fact , the combined use of stromal Cav-1 and stromal MCT4 allowed us to more precisely identify high-risk triple-negative breast cancer patients , consistent with the goal of individualized risk-assessment and personalized cancer treatment . However , epithelial MCT4 staining had no prognostic value , indicating that the " conventional " Warburg effect does not predict clinical outcome . Thus , the " Reverse Warburg Effect " or " parasitic " energy-transfer is a key determinant of poor overall patient survival . As MCT4 is a druggable-target , MCT4 inhibitors should be developed for the treatment of aggressive breast cancers , and possibly other types of human cancers . Similarly , we discuss how stromal MCT4 could be used as a biomarker for identifying high-risk cancer patients that could likely benefit from treatment with FDA-approved drugs or existing MCT-inhibitors ( such as , AR-C155858 , AR-C117977 , and AZD-3965 ) .
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22313602
|
Mps one binder 1a ( MOB1A ) and MOB1B are key components of the Hippo signaling pathway and are mutated or inactivated in many human cancers . Here we show that intact Mob1a or Mob1b is essential for murine embryogenesis and that loss of the remaining WT Mob1 allele in Mob1a(\u0394/\u0394)1b(tr/+) or Mob1a(\u0394/+)1b(tr/tr) mice results in tumor development . Because most of these cancers resembled trichilemmal carcinomas , we generated double-mutant mice bearing tamoxifen-inducible , keratinocyte-specific homozygous-null mutations of Mob1a and Mob1b ( kDKO mice). kDKO mice showed hyperplastic keratinocyte progenitors and defective keratinocyte terminal differentiation and soon died of malnutrition. kDKO keratinocytes exhibited hyperproliferation , apoptotic resistance , impaired contact inhibition , enhanced progenitor self renewal , and increased centrosomes . Examination of Hippo pathway signaling in kDKO keratinocytes revealed that loss of Mob1a/b altered the activities of the downstream Hippo mediators LATS and YAP1 . Similarly , YAP1 was activated in some human trichilemmal carcinomas , and some of these also exhibited MOB1A/1B inactivation . Our results clearly demonstrate that MOB1A and MOB1B have overlapping functions in skin homeostasis , and exert their roles as tumor suppressors by regulating downstream elements of the Hippo pathway .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
23143302
|
OBJECTIVES/HYPOTHESIS Head and neck squamous cell carcinoma ( HNSCC ) is a complex disease process involving interactions with carcinoma-associated fibroblasts and endothelial cells . We further investigated these relationships by suppressing stromal cell growth through the inhibition of fibroblast growth factor receptor ( FGFR ) . STUDY DESIGN Preclinical investigation . METHODS HNSCC cell lines ( FADU , OSC19 , Cal27 , SCC1 , SCC5 , SCC22A ) , fibroblast ( HS27 ) , and endothelial cells ( human umbilical vascular endothelial cell ) were cultured individually or in coculture . Proliferation was assessed following treatment with a range of physiologic concentrations of FGFR inhibitor PD173074 . Mice bearing established HNSCC xenografts were treated with PD173074 ( 12 mg/kg ) , and tumor histology was analyzed for stromal composition , proliferation ( Ki67 staining ) , and apoptosis ( TUNEL [ terminal deoxynucleotidyl transferase dUTP nick end labeling ] staining ) . RESULTS In vitro , inhibition of FGFR with PD173074 dramatically reduced proliferation of fibroblasts and endothelial cells compared to untreated controls . However , HNSCC cell proliferation was not affected by inhibition of FGFR . When cocultured with fibroblasts , HNSCC cells proliferation increased by 15% to 80% ( P < .01 ) . Furthermore , this fibroblast-enhanced tumor cell growth was suppressed by FGFR inhibition . Additionally , treatment of mice bearing HNSCC xenografts with PD173074 resulted in significant growth inhibition ( P < .001 ) . Additionally , those tumors from mice treated with PD173074 had a smaller stromal component , decreased proliferation , and increased apoptosis . CONCLUSIONS Targeting the FGFR pathway in head and neck cancer acts through the stromal components to decrease HNSCC growth in vivo and in vitro .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22460537
|
There are contradictory observations about the different radiosensitivities of cancer stem cells and cancer non-stem cells . To resolve these contradictory observations , we studied radiosensitivities by employing breast cancer stem cell ( CSC)-like MDA-MB231 and MDA-MB453 cells as well as their corresponding non-stem cells . CSC-like cells proliferate without differentiating and have characteristics of tumor-initiating cells [ 1 ] . These cells were exposed to \u03b3-rays ( 1.25-8.75 Gy ) and survival curves were determined by colony formation . A final slope , D(0) , of the survival curve for each cell line was determined to measure radiosensitivity . The D(0) of CSC-like and non-stem MDA-MB-453 cells were 1.16 Gy and 1.55 Gy , respectively . Similar results were observed in MDA-MB-231 cells ( 0.94 Gy vs. 1.56 Gy ) . After determination of radiosensitivity , we investigated intrinsic cellular determinants which influence radiosensitivity including cell cycle distribution , free-radical scavengers and DNA repair . We observed that even though cell cycle status and antioxidant content may contribute to differential radiosensitivity , differential DNA repair capacity may be a greater determinant of radiosensitivity . Unlike non-stem cells , CSC-like cells have little/no sublethal damage repair , a low intracellular level of ataxia telangiectasia mutated ( ATM ) and delay of \u03b3-H2AX foci removal ( DNA strand break repair ) . These results suggest that low DNA repair capacity is responsible for the high radiosensitivity of these CSC-like cells .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23185620
|
Hormone replacement therapy , which is a common menopausal treatment , is contraindicated in women with breast cancers due to concerns regarding the potential for breast cell proliferation . As such , there is a need for alternative methods for treating menopausal symptoms . To determine the influence of one such alternative , black cohosh ( Cimicifuga racemosa [ CR] ) , on estrogen-dependent mammary cancers , we conducted an in vitro investigation of the effect of an isopropanolic CR-extract on the proliferation of estrogen receptor-positive breast cancer cells . The experiments were performed using the human breast adenocarcinoma ( MCF-7 ) cell test system , an established in vitro model for estrogen-dependent tumors . The influence of CR-extract on the proliferation of the MCF-7 cells was determined by measuring the incorporation of radioactively labeled thymidine . Under estrogen-deprived conditions , the CR-extract ( 10(-3)-10(-5) dilutions ) significantly inhibited MCF-7 cell proliferation . Additionally , application of the CR-extract inhibited estrogen-induced proliferation of MCF-7 cells . Moreover , the proliferation-inhibiting effect of tamoxifen was enhanced by the CR-extract . Such data that suggest a non-estrogenic , or estrogen-antagonistic effect of CR on human breast cancer cells lead to the conclusion that CR treatment may be a safe , natural remedy for menopausal symptoms in breast cancer .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
12408370
|
We have recently developed surface-shielded transferrin-polyethylenimine ( Tf-PEI)/DNA delivery systems that target reporter gene expression to distant tumors after systemic application . In the present study , we used surface-shielded Tf-PEI/DNA complexes for delivering the gene for a highly potent cytokine , tumor necrosis factor-alpha ( TNFalpha ) . TNFalpha is known for its ability to induce hemorrhagic tumor necrosis and tumor regression . However , the therapeutic application of TNFalpha is hampered by its high systemic toxicity dictating the need to target TNFalpha activity to the tumor . Systemic application of surface-shielded Tf-PEI complexes with the TNFalpha gene resulted in preferential expression of TNFalpha in the tumor without detectable TNFalpha serum levels , in contrast to the application of nontargeted complexes . Tumor-targeted TNFalpha gene delivery induced pronounced hemorrhagic tumor necrosis and inhibition of tumor growth in three murine tumor models of different tissue origins , Neuro2a neuroblastoma , MethA fibrosarcoma , and M-3 melanoma , with complete tumor regressions observed in the MethA model . No systemic TNF-related toxicity was observed due to the localization of the TNFalpha activity to the tumor . Targeted gene therapy may be an attractive strategy applicable to highly active , yet toxic , molecules such as TNFalpha .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
12136428
|
Angiogenic factors produced by monocytes-macrophages are involved in the pathogenesis of chronic inflammatory disorders characterized by persistent angiogenesis . The possibility was tested that interleukin-8 ( IL-8 ) , which is a cytokine that is chemotactic for lymphocytes and neutrophils , is also angiogenic . Human recombinant IL-8 was potently angiogenic when implanted in the rat cornea and induced proliferation and chemotaxis of human umbilical vein endothelial cells . Angiogenic activity present in the conditioned media of inflamed human rheumatoid synovial tissue macrophages or lipopolysaccharide-stimulated blood monocytes was equally blocked by antibodies to either IL-8 or tumor necrosis factor-alpha . An IL-8 antisense oligonucleotide specifically blocked the production of monocyte-induced angiogenic activity . These data suggest a function for macrophage-derived IL-8 in angiogenesis-dependent disorders such as rheumatoid arthritis , tumor growth , and wound repair .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
1281554
|
We have observed previously that treatment of plateau-phase L5178Y murine lymphoblasts in vitro with 2'-deoxycoformycin plus deoxyadenosine ( dCF/dAdo ) can inhibit the repair of X-irradiation-induced DNA single-strand breaks ( SSB ) in these cells and that this effect is associated with synergistic cell kill . In this study we examined the effect of a combination treatment of plateau-phase L5178Y cells with bleomycin ( BLM ) plus dCF/dAdo . Incubation of BLM-treated cells with dCF/dAdo resulted in significant inhibition of the repair of BLM-induced DNA SSB . However , an additive , but not a synergistic , increase in cell kill was observed when cells were treated with a combination of BLM plus dCF/dAdo .
|
[
0,
0,
0,
0,
0,
1,
0,
1,
0,
0
] |
1282003
|
Src kinase is elevated in breast tumors that are ER/PR negative and do not overexpress HER2 , but clinical trials with Src inhibitors have shown little activity . The present study evaluated preclinical efficacy of a novel peptidomimetic compound , KX-01 ( KX2-391 ) , that exhibits dual action as an Src and pretubulin inhibitor . KX-01 was evaluated as a single-agent and in combination with paclitaxel in MDA-MB-231 , MDA-MB-157 , and MDA-MB-468 human ER/PR/HER2-negative breast cancer cells . Treatments were evaluated by growth/apoptosis , isobologram analysis , migration/invasion assays , tumor xenograft volume , metastasis , and measurement of Src , focal adhesion kinase ( FAK ) , microtubules , Ki67 , and microvessel density . KX-01 inhibited cell growth in vitro and in combination with paclitaxel resulted in synergistic growth inhibition . KX-01 resulted in a dose-dependent inhibition of MDA-MB-231 and MDA-MB-157 tumor xenografts ( 1 and 5 mg/kg , twice daily ) . KX-01 inhibited activity of Src and downstream mediator FAK in tumors that was coincident with reduced proliferation and angiogenesis and increased apoptosis . KX01 also resulted in microtubule disruption in tumors . Combination of KX-01 with paclitaxel resulted in significant regression of MDA-MB-231 tumors and reduced metastasis to mouse lung and liver . KX-01 is a potently active Src/pretubulin inhibitor that inhibits breast tumor growth and metastasis . As ER/PR/HER2-negative patients are candidates for paclitaxel therapy , combination with KX-01 may potentiate antitumor efficacy in management of this aggressive breast cancer subtype .
|
[
1,
0,
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0,
0,
0,
1,
1,
1,
0
] |
22784709
|
PURPOSE Overproduction of reactive oxygen species ( ROS ) intermediates above the functional capability of cellular antioxidants may result in instability of important macromolecules and represents the molecular basis of many diseases including inflammation processes , cardiovascular alterations , cancer etc . The purpose of this study was to determine plasma level of superoxide anion , hydrogen-peroxide and malondialdehyde ( MDA ) as markers of oxidative stress and activities of superoxide dismutase ( SOD ) , catalase ( CAT ) and glutathione peroxidase ( GPx ) as antioxidant enzymes in B-chronic lymphocytic leukemia ( B-CLL ) patients . METHODS The study included 29 untreated B-CLL patients in stage A , and 21 in stages B and C , classified according to the Binet system ; 31 healthy volunteers formed the control group . After centrifugation of heparinized peripheral blood , plasma levels of all investigated parameters were determined using spectrophotometric methods . RESULTS Plasma CAT activity was increased in B-CLL patients compared with control subjects ; also , progression of disease was related with significantly higher plasma activity of CAT . Also , B-CLL patients showed significantly higher plasma concentration of MDA compared with controls . No statistically significant differences of superoxide anion and hydrogen peroxide as well as plasma activity of SOD and GPx between the tested groups were noted . CONCLUSION Increase of CAT activity in B-CLL patients indicates that there is stimulation of the antioxidant enzyme system , while the increase of MDA concentration shows increased lipid peroxidation level . According to these results it could be concluded that an imbalance exists between oxidants and antioxidants in the plasma of B-CLL patients .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
20658731
|
Identification of molecular target(s) and mechanism(s) of silica-induced pulmonary toxicity is important for the intervention and/or prevention of diseases associated with exposure to silica . Rats were exposed to crystalline silica by inhalation ( 15 mg m(-3) , 6 h per day , 5 days ) and global gene expression profile was determined in the lungs by microarray analysis at 1 , 2 , 4 , 8 and 16 weeks following termination of silica exposure . The number of significantly differentially expressed genes ( >1.5-fold change and <0.01 false discovery rate P-value ) detected in the lungs during the post-exposure time intervals analyzed exhibited a steady increase in parallel with the progression of silica-induced pulmonary toxicity noticed in the rats . Quantitative real-time PCR analysis of a representative set of 10 genes confirmed the microarray findings . The number of biological functions , canonical pathways and molecular networks significantly affected by silica exposure , as identified by the bioinformatics analysis of the significantly differentially expressed genes detected during the post-exposure time intervals , also exhibited a steady increase similar to the silica-induced pulmonary toxicity . Genes involved in oxidative stress , inflammation , respiratory diseases , cancer , and tissue remodeling and fibrosis were significantly differentially expressed in the rat lungs ; however , unresolved inflammation was the single most significant biological response to pulmonary exposure to silica . Excessive mucus production , as implicated by significant overexpression of the pendrin coding gene , SLC26A4 , was identified as a potential novel mechanism for silica-induced pulmonary toxicity . Collectively , the findings of our study provided insights into the molecular mechanisms underlying the progression of crystalline silica-induced pulmonary toxicity in the rat . Published 2012 . This article is a US Government work and is in the public domain in the USA .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
22431001
|
Neutrophils have become recognised as important contributors to the effectiveness of tumour eradication by photodynamic therapy ( PDT ) . In this study , we have used the mouse SCCVII squamous cell carcinoma model to investigate the activity of neutrophils in tumours treated by PDT . Tumour levels of neutrophilic myeloperoxidase ( MPO ) demonstrated not only a massive and sustained sequestration of these cells in PDT-treated tumours but also revealed their activated state evidenced by the presence of released MPO . Among the adhesion molecules expressed on tumour vascular endothelium , ICAM-1 appears to be of primary importance in the invasion of neutrophils into PDT-treated tumours , because its functional blocking with monoclonal antibodies reduced the tumour cure rate . A marked upregulation of its ligands CD11b/CD18 and CD11c/CD18 found on neutrophils associated with PDT-treated tumours supports this assumption . To evaluate the role of inflammatory cytokines regulating neutrophil activity , neutralising antibodies were given to mice before PDT treatment . The results suggest that IL-1beta activity is critical for the therapeutic outcome , since its neutralisation diminished the cure rates of PDT-treated tumours . No significant effect was observed with anti-IL-6 and anti-TNF-alpha treatment . Further flow cytometry-based examination of neutrophils round in PDT-treated tumours revealed that these cells express MHC class II molecules , which suggests their engagement as antigen-presenting cells and involvement in the development of antitumour immune response .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
12665307
|
There is increasing evidence for the implication of tumor-derived angiogenic and anti-angiogenic factors in controlling tumor growth in vivo . In this study , we documented the production of inhibitors of angiogenesis by pancreatic cancer cells and examined how changes in the balance between pro- and anti-angiogenic factors regulate tumor growth in vivo . The human pancreatic cancer cell line Hs-776T ( HS-W ) produces slow-growing tumors in SCID mice . Cells of a variant form ( HS-R ) of Hs-776T produced faster-growing tumors compared to HS-W . Characterization of HS-W and HS-R cells in vitro showed similar proliferation rates and production of the angiogenic factors vascular endothelial growth factor ( VEGF ) and basic fibroblast growth factor ( bFGF ) . Analyzes of anti-angiogenic factors showed comparable levels of angiostatin and thrombospondin 1 and 2 , but endostatin was only detected in conditioned media of HS-W cells and was absent in HS-R . Cell proliferation was similar in both tumor types in vivo , whereas HS-W tumors demonstrated increased apoptosis with a high percentage of apoptotic endothelial cells ( EC ) . Subsequently , VEGF was over-expressed in Hs-776T cells ( HS-VF ) , resulting in rapidly growing tumors and lowering tumor and EC apoptosis . Collectively , our study confirms that tumor growth is dependent on its ability to increase the angiogenic stimulus or to reduce the amounts of endogenous anti-angiogenic factors .
|
[
0,
0,
0,
0,
0,
0,
1,
1,
1,
0
] |
12831059
|
AIM To compare the value of intravenous contrast-enhanced ultrasonography ( US ) , intravenous contrast-enhanced computed tomography ( CT ) , and magnetic resonance imaging ( MRI ) in the diagnosis of hepatic hemangiomas . MATERIAL AND METHODS The study enrolled 48 patients , aged between 20 and 79 years ( 35 [ 72.9% ] women , 13 [ 27.1% ] men ; mean age , 53.5+/-12.855 years ) , who were examined and treated in the Departments of Gastroenterology , Surgery , and Oncology , Hospital of Kaunas University of Medicine , in the year 2007 . All patients underwent intravenous contrast-enhanced US , intravenous contrast-enhanced CT , and MRI and were diagnosed with hepatic hemangioma according to the findings of these examinations . RESULTS The size of hemangiomas was < or =2.0 cm in 20 cases ( 41.7% ) and >2.0 cm in 28 ( 58.3% ) . No association between hepatic hemangioma and patient's age was found ( chi(2)=0.547 , df=2 , P=0.761 ) . Nearly one-third of hemangiomas were located in the segment IV of the left hepatic lobe . There were a few complicated hemangiomas in the study sample : 2 with calcification and 1 with necrosis . The sensitivity of CT in the diagnosis of hepatic hemangioma was 76.92% ; specificity , 33.3% ; positive prognostic value , 83.3% ; and negative prognostic value , 25.0% . The sensitivity of intravenous contrast-enhanced US in the diagnosis of hepatic hemangioma was 77.8% ; specificity , 100% ; positive prognostic value , 100% ; and negative prognostic value , 23.1% . CONCLUSIONS Intravenous contrast-enhanced US is more specific than intravenous contrast-enhanced CT in the diagnosis of hepatic hemangioma ( P=0.0005 ) and has a higher positive prognostic value ( P=0.001 ) .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
20679748
|
BACKGROUND Angiogenic factors following oncological surgery is important in tumor recurrence . Vascular endothelial growth factor ( VEGF ) , angiopoietin 1 ( Ang-1 ) , Ang-2 , soluble VEGF-receptor 1 ( sVEGFR1 ) and sVEGFR2 may influence angiogenesis . This prospective study examined the influence of open and video-assisted thoracic surgery ( VATS ) lung resections for early stage non-small cell lung cancer ( NSCLC ) on postoperative circulating angiogenic factors . METHODS Forty-three consecutive patients underwent major lung resection through either VATS ( n = 23 ) or Open thoracotomy ( n = 20 ) over an 8-month period . Blood samples were collected preoperatively and postoperatively on days ( POD ) 1 and 3 for enzyme linked immunosorbent assay determination of angiogenic factors . RESULTS Patient demographics were comparable . For all patients undergoing major lung resection , postoperative Ang-1 and sVEGFR2 levels were significantly decreased , while Ang-2 and sVEGFR1 levels markedly increased . No significant peri-operative changes in VEGF levels were observed . Compared with open group , VATS had significantly lower plasma levels of VEGF ( VATS 170 ± 93 pg/mL ; Open 486 ± 641 pg/mL ; P = 0.04 ) and Ang-2 ( VATS 2484 ± 1119 pg/mL ; Open 3379 ± 1287 pg/mL ; P = 0.026 ) on POD3 . CONCLUSIONS Major lung resection for early stage NSCLC leads to a pro-angiogenic status , with increased Ang-2 and decreased Ang-1 productions . VATS is associated with an attenuated angiogenic response with lower circulating VEGF and Ang-2 levels compared with open . Such differences in angiogenic factors may be important in lung cancer biology and recurrence following surgery .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
23024612
|
BACKGROUND Prostate cancer ( PCa ) progression is often associated with transactivation of the androgen receptor ( AR ) by endogenous hormones/growth factors . One such factor affecting growth , proliferation , and apoptostis ( pro-/anti- ) in various cancers is the adipokine leptin . This research studied leptin-induced signaling and apoptosis in androgen sensitive ( LNCaP , PC3/AR ) and insensitive ( PC3 , DU145 ) PCa cell lines . METHODS Signaling was studied by immunoblotting in cells overexpressing leptin receptors ( LRb ) , Janus kinase 2 ( JAK2 ) , and kinase negative-HER2-YFP cDNAs . Apoptosis was measured by immunoblotting of apoptotic proteins and by Hoechst staining of condensed DNA . RESULTS Leptin rapidly induced activation of JAK2 , STAT3 , and MAPK ( ERK1/2 ) signaling cascades ; it may also induce HER2 transactivation via leptin-induced phospho-JAK2 . Leptin was then shown to exert clear pro-apoptotic effects , increasing levels of caspase 3 , cleavage of its substrate , poly ( ADP-ribose ) polymerase ( PARP ) to cleaved PARP(89) , levels of CK 18 , a cytoskeletal protein formed during apoptosis , and DNA condensation . Kinase inhibitors indicated that leptin-induced apoptosis is probably mediated by balanced activation of JAK2/STAT3 , p38 MAPK , and PKC pathways in PCa cells . A human leptin mutein LRb antagonist , L39A/D40A/F41A , fully inhibited leptin-induced phosphorylation of JAK2 , ERK1/2 , and Akt/PKB , and partially abrogated effects on apoptotic proteins . In LNCaP and PC3/AR cells , leptin increased AR protein levels in correlation with raised apoptotic markers . Thus , AR may mediate , at least partly , the leptin-induced apoptotic response . CONCLUSIONS Leptin can clearly induce apoptosis in human PCa cell lines . These findings could lead to development of new leptin agonists with enhanced pro-apoptotic effects and targeted for use in human PCa .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
21541970
|
Novel strategies are necessary to improve chemotherapy response in advanced and recurrent endometrial cancer . Here , we demonstrate that terpenoids present in the Steam Distilled Extract of Ginger ( SDGE ) are potent inhibitors of proliferation of endometrial cancer cells . SDGE , isolated from six different batches of ginger rhizomes , consistently inhibited proliferation of the endometrial cancer cell lines Ishikawa and ECC-1 at IC(50) of 1.25 �g/ml . SDGE also enhanced the anti-proliferative effect of radiation and cisplatin . Decreased proliferation of Ishikawa and ECC-1 cells was a direct result of SDGE-induced apoptosis as demonstrated by FITC-Annexin V staining and expression of cleaved caspase 3 . GC/MS analysis identified a total of 22 different terpenoid compounds in SDGE , with the isomers neral and geranial constituting 30-40% . Citral , a mixture of neral and geranial inhibited the proliferation of Ishikawa and ECC-1 cells at an IC(50) 10 �M ( 2.3 �g/ml ) . Phenolic compounds such as gingerol and shogaol were not detected in SDGE and 6-gingerol was a weaker inhibitor of the proliferation of the endometrial cancer cells . SDGE was more effective in inducing cancer cell death than citral , suggesting that other terpenes present in SDGE were also contributing to endometrial cancer cell death . SDGE treatment resulted in a rapid and strong increase in intracellular calcium and a 20-40% decrease in the mitochondrial membrane potential . Ser-15 of p53 was phosphorylated after 15 min treatment of the cancer cells with SDGE . This increase in p53 was associated with 90% decrease in Bcl2 whereas no effect was observed on Bax . Inhibitor of p53 , pifithrin-α , attenuated the anti-cancer effects of SDGE and apoptosis was also not observed in the p53(neg) SKOV-3 cells . Our studies demonstrate that terpenoids from SDGE mediate apoptosis by activating p53 and should be therefore be investigated as agents for the treatment of endometrial cancer .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
23300887
|
Inflammatory responses and associated products have been implicated in cancer metastasis . However , the relationship between these two processes is uncertain due to the lack of a suitable model . Taking advantage of localized and controllable inflammatory responses induced by biomaterial implantation and the capability of tissue scaffolds to release a wide variety of chemokines , we report a novel system for studying the molecular mechanisms of inflammation-mediated cancer metastasis . The animal model is comprised of an initial subcutaneous implantation of biomaterial microspheres which prompt localized inflammatory responses , followed by the transplantation of metastatic cancer cells into the peritoneal cavity or blood circulation . Histological results demonstrated that substantial numbers of B16F10 cells were recruited to the site nearby biomaterial implants . There was a strong correlation between the degree of biomaterial-mediated inflammatory responses and number of recruited cancer cells . Inflammation-mediated cancer cell migration was inhibited by small molecule inhibitors of CXCR4 but not by neutralizing antibody against CCL21 . Using chemokine-releasing scaffolds , further studies were carried out to explore the possibility of enhancing cancer cell recruitment . Interestingly , erythropoietin ( EPO ) releasing scaffolds , but not stromal cell-derived factor-1α-releasing scaffolds , were found to accumulate substantially more melanoma cells than controls . Rather unexpectedly , perhaps by indirectly reducing circulating cancer cells , mice implanted with EPO-releasing scaffolds had longer life span than other groups . These results suggest that chemokine-releasing scaffolds may potentially function as implantable cancer traps and serve as powerful tools for studying cancer distraction and even selective annihilation of circulating metastatic cancer cells .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22019117
|
It is well known that cell-mediated immunity is suppressed in patients with neoplastic diseases . We have reported that soluble receptors for interleukin-2 ( sIL-2R ) and tumor necrosis factor ( sTNF-R1 ) are elevated in the serum of patients with advanced colorectal cancer . The presence of these soluble receptors and immunosuppressive cytokines , including interleukin-10 ( IL-10 ) , might be important in the mechanisms of immunosuppression. cis-Diaminedichloroplatinum ( cisplatin ) has been reported to immunomodulate , especially when used in low dose in combination with 5-Fluorouracil ( 5-FU ) . In this study , cisplatin and UFT , a form of uracil and tegafur which is a prodrug of 5-FU , were administered with immunomodulator Polysaccharide K ( PSK ) to ten patients with colorectal cancer , who showed distant metastasis in the liver or lung , and the serum levels of sIL-2R and sTNF-R1 and the production of gamma-interferon ( gamma-INF ) and interleukin-10 by peripheral blood mononuclear cells were measured . The serum concentrations of sIL-2R and the production of IL-10 were reduced ( p < 0.05 ) after 2 months of treatment . Thus , this combination appeared to have immunomodulative potential in patients with advanced colorectal cancer .
|
[
1,
1,
0,
0,
0,
0,
0,
0,
0,
0
] |
11901535
|
MicroRNAs ( miRNAs ) are small non-coding RNAs of nucleotides that function as negative regulators of gene expression by either inhibiting translation or inducing deadenylation-dependent degradation of target transcripts . Notably , deregulation of miRNAs expression is associated with the initiation and progression of human cancers where they act as oncogenes or tumor suppressors contributing to tumorigenesis . Abnormal miRNA expression may provide potential diagnostic and prognostic tumor biomarkers and new therapeutic targets in cancer . Recently , several miRNAs have been shown to initiate invasion and metastasis by targeting multiple proteins that are major players in these cellular events , thus they have been denominated as metastamiRs . Here , we present a review of the current knowledge of miRNAs in cancer with a special focus on metastamiRs . In addition we discuss their potential use as novel specific markers for cancer progression .
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[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22408395
|
An acquired mutation ( T790M ) in the epidermal growth factor receptor ( EGFR ) accounts for half of all relapses in non-small cell lung cancer ( NSCLC ) patients who initially respond to EGFR kinase inhibitors . In this study , we demonstrated for the first time that EGFR-T790M interacts with the cytoskeletal components , myosin heavy chain 9 ( MYH9 ) and β-actin , in the nucleus of H1975 cells carrying the T790M-mutant EGFR . The interactions of EGFR with MYH9 and β-actin were reduced in the presence of blebbistatin , a specific inhibitor for the MYH9-β-actin interaction , suggesting that the EGFR interaction with MYH9 and β-actin is affected by the integrity of the cytoskeleton . These physical interactions among MYH9 , β-actin , and EGFR were also impaired by CL-387,785 , a kinase inhibitor for EGFR-T790M . Furthermore , CL-387,785 and blebbistatin interacted in a synergistic fashion to suppress cell proliferation and induce apoptosis in H1975 cells . The combination of CL-387,785 and blebbistatin enhanced the down-regulation of cyclooxygenase-2 ( COX-2 ) , a transcriptional target of nuclear EGFR . Overall , our findings demonstrate that disrupting EGFR interactions with the cytoskeletal components enhanced the anti-cancer effects of CL-387,785 against H1975 cells , suggesting a novel therapeutic approach for NSCLC cells that express the drug-resistant EGFR-T790M .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22366308
|
The results of experimental studies have indicated the pleiotropic effects of statins in organism , e.g. the influence on cell cycle , apoptosis or angiogenesis . In this study , the effects of simvastatin on selected parameters of apoptosis and proliferation in chemocarcinogen-induced mammary tumorigenesis in female rats were determined . Simvastatin was administered dietary at a dose of 18 mg/kg and highly effective dose of 180 mg/kg the entire experiment ( 18 weeks ) . At autopsy mammary tumors were removed and prepared for immunohistochemical and histomorphological analysis . In treated animals ( simvastatin 180 mg/kg ) , significant decrease by 12% in Bcl-2 protein expression and non-significant decrease by 27% of Ki67 protein expression in tumor cells compared to tumor cells in control animals were observed after semiquantitative evaluation . Morphometrical analysis has shown significant proapototic shift in Bcl-2/Bax ratio in tumor cells . In high grade control carcinoma cells , the expression of Ki67 increased by 37% ( non-significantly ) in comparison with control low grade carcinomas . A histomorphological analysis of malignant tumors has revealed a shift from high grade to low grade carcinomas after simvastatin treatment . The noticeable decrease of mammary tumor frequency and incidence in rats after simvastatin treatment was accompanied with antiapoptotic Blc-2 protein decrease and proapoptotic Bax protein increase in this experiment .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
22668016
|
Estrogen receptor ( ER ) and NF-κB are transcription factors with profound effects on breast cancer cell proliferation and survival . While many studies demonstrate that ER and NF-κB can repress each other , we previously identified a gene signature that is synergistically upregulated by these two factors in more aggressive luminal B breast tumors . Herein , we examine a novel mechanism of cross talk between ER and NF-κB that results in the upregulation of the antiapoptotic gene BIRC3 ( also known as cIAP2 ) . We demonstrate that NF-κB , acting through two response elements , is required for ER recruitment to an adjacent estrogen response element ( ERE ) in the BIRC3 promoter . This effect is accompanied by a major increase in NF-κB-dependent histone acetylation around the ERE . Interestingly , CBP , a histone acetyltransferase previously implicated in repressive interactions between ER and NF-κB , plays a permissive role by promoting histone acetylation and ER recruitment , as well as enhanced expression of BIRC3 . These findings suggest a new gene regulatory mechanism by which inflammation and NF-κB activation can influence ER recruitment to inherently inactive ER binding sites . This fine-tuning mechanism may explain how two factors that generally repress each other's activity may work together on certain genes to promote breast cancer cell survival and tumor progression .
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[
0,
0,
0,
0,
0,
0,
0,
0,
1,
1
] |
22083956
|
We investigated the mode of cell death induced by the anthracyclines , aclarubicin , doxorubicin and daunorubicin in the human leukemia cell lines , HL60 and Jurkat . The cells were incubated with drug concentrations up to 500 nM for periods between 3 and 24 hours , followed by morphological and biochemical analyses . All three substances induced DNA fragmentation , evident as DNA laddering and appearance of cells with hypodiploid DNA content , externalization of phosphatidyl serine , activation of caspases and degradation of the apoptosis-specific endonuclease inhibitor DFF45 . However , concentrations and times necessary for these effects to occur were different , aclarubicin being the quickest acting drug with a lag phase of 3 h , followed by daunorubicin with 6 h and doxorubicin with 24 h . More importantly , aclarubicin induced these effects while the cell membrane was intact , whereas doxorubicin and daunorubicin led to immediate loss of membrane integrity . Programmed cell death is characterised by preservation of membrane integrity in order to allow removal of apoptotic bodies , whereas cell rupture is an early event in necrosis . We therefore suggest that , in our experimental settings , doxorubicin- and daunorubicin-induced cell death occurs by necrosis , while aclarubicin induces programmed cell death .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
12370496
|
BACKGROUND & OBJECTIVE Usually pituitary adenomas are histological benign and grow slowly , but a proportion of them will become locally aggressive , and develop into invasive pituitary adenomas . The reasons for these differences in tumor behavior are poorly understood . Pituitary adenomas are abounding blood vessels . Angiogenesis and tumor invasion both require degradation of the extracellular matrix components to allow cell migration . The matrix metalloproteinases ( MMPs ) and their nature inhibitors-the tissue inhibitors of metalloproteinases ( TIMPs ) may play a central role in these processes . The aggressive mechanism of pituitary adenomas was studied through investigating the expression of MMP-9 , MMP-2 , TIMP-1 , and TIMP-2 in both invasive and non-invasive adenomas . METHODS Sixty-one surgical removed pituitary adenomas ( forty-nine cases invasive and twelve non-invasive adenomas ) were investigated . Immunohistochemistry staining ( SP method ) was used to detect the expression of MMP-9 , MMP-2 , TIMP-1 , and TIMP-2 in two groups . The results were treated with semi-quantitative method and analyzed by using non-parameter rank sum test . RESULTS Immunohistochemical staining of tumor cells for MMP-9 , TIMP-1 , MMP-2 , and TIMP-2 were noted 95.9% ( 47/49 ) , 57.1% ( 28/49 ) , 75.5% ( 37/49 ) and 89.8% ( 44/49 ) in invasive adenomas , and 100% ( 12/12 ) , 91.7% ( 11/12 ) , 66.7% ( 8/12 ) , and 91.7% ( 11/12 ) in non-invasive adenomas , respectively . Invasive tumors were significantly less expressing TIMP-1 and TIMP-2 ( P < 0.05 ) . There was no significant difference for MMP-9 or MMP-2 between invasive and non-invasive groups ( P > 0.05 ) . CONCLUSIONS TIMP-1 and TIMP-2 may play a key role in invasive pituitary adenomas to biological behavior .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
12508658
|
The biological activities of tocotrienols are receiving increasing attention . Herein , we report the efficacy of a mixed-tocotrienol diet against prostate tumorigenesis in the transgenic adenocarcinoma mouse prostate ( TRAMP ) mouse model . Male TRAMP mice , 8 wk old , were fed 0.1% , 0.3% , or 1% mixed tocotrienols in AIN-76A diet up to 24 wk old . Likewise , a positive control group consisting of male TRAMP mice and a negative control group consisting of wild-type nontransgenic mice were fed regular AIN-76A diet up to 24 wk old . Our results show that mixed-tocotrienol-fed groups had a lower incidence of tumor formation along with a significant reduction in the average wet weight of genitourinary apparatus . Furthermore , mixed tocotrienols significantly reduced the levels of high-grade neoplastic lesions as compared to the positive controls . This decrease in levels of high-grade neoplastic lesions was found to be associated with increased expression of proapoptotic proteins BAD ( Bcl(2) antagonist of cell death ) and cleaved caspase-3 and cell cycle regulatory proteins cyclin dependent kinase inhibitors p21 and p27 . In contrast , the expression of cyclins A and E were found to be decreased in mixed-tocotrienol groups . Taken together , our results show that by modulating cell cycle regulatory proteins and increasing expression of proapoptotic proteins , mixed tocotrienols suppress prostate tumorigenesis in the TRAMP mice .
|
[
0,
0,
0,
0,
1,
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1,
1,
0
] |
20661828
|
Many viruses subvert the host cell's ability to mount and complete various DNA damage responses ( DDRs ) after infection . HCMV infection of permissive fibroblasts activates host DDRs at the time of viral deposition and during replication , but the DDRs remain uncompleted without arrest or apoptosis . We believe this was in part due to partitioning of the damage response and double strand break repair components . After extraction of soluble proteins , the localization of these components fell into three groups : specifically associated with the viral replication centers ( RCs ) , diffused throughout the nucleoplasm and excluded from the RCs . Others have shown that cells are incapable of processing exogenously introduced damage after infection . We hypothesized that the inability of the cells to process damage might be due to the differential association of repair components within the RCs and , in turn , potentially preferential repair of the viral genome and compromised repair of the host genome . To test this hypothesis we used multiple strategies to examine repair of UV-induced DNA damage in mock and virus-infected fibroblasts . Comet assays indicated that repair was initiated , but was not completed in infected cells . Quantitative analysis of immunofluorescent localization of cyclobutane pyrimidine dimers ( CPDs ) revealed that after 24 h of repair , CPDs were significantly reduced in viral DNA , but not significantly changed in the infected host DNA . To further quantitate CPD repair , we developed a novel dual-color Southern protocol allowing visualization of host and viral DNA simultaneously . Combining this Southern methodology with a CPD-specific T4 endonuclease V alkaline agarose assay to quantitate repair of adducts , we found efficient repair of CPDs from the viral DNA but not host cellular DNA . Our data confirm that NER functions in HCMV-infected cells and almost exclusively repairs the viral genome to the detriment of the host's genome .
|
[
0,
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1,
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0,
0,
0
] |
23209410
|
Airway mucin secretion and MC ( mast cell ) degranulation must be tightly controlled for homoeostasis of the lungs and immune system respectively . We found the exocytic protein Munc18b to be highly expressed in mouse airway epithelial cells and MCs , and localized to the apical pole of airway secretory cells . To address its functions , we created a mouse with a severely hypomorphic Munc18b allele such that protein expression in heterozygotes was reduced by Homozygous mutant mice were not viable , but heterozygotes showed a reduction in stimulated release of mucin from epithelial cells and granule contents from MCs . The defect in MCs affected only regulated secretion and not constitutive or transporter-mediated secretion . The severity of passive cutaneous anaphylaxis was also reduced by showing that reduction of Munc18b expression results in an attenuation of physiological responses dependent on MC degranulation . The Munc18b promoter is controlled by INR ( initiator ) , Sp1 ( specificity protein 1 ) , Ets , CRE ( cAMP-response element ) , GRE ( glucocorticoid-response element ) , GATA and E-box elements in airway epithelial cells ; however , protein levels did not change during mucous metaplasia induced by allergic inflammation . Taken together , the results of the present study identify Munc18b as an essential gene that is a limiting component of the exocytic machinery of epithelial cells and MCs .
|
[
0,
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0,
0,
0,
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0,
0
] |
22694344
|
Chromated copper arsenate , which is used worldwide as a wood preservative , can adversely affect human health . Accumulating evidence suggests that chromium ( Cr ) and arsenic ( As ) can potentially disrupt the redox balance and cause respiratory diseases and cancer in humans . The present study was designed to determine the combined toxic effects of these metals in the lungs and to clarify the specific molecules that are stimulated by combined exposure to both metals . Male C57BL/6J mice were intratracheally instilled with arsenate [ As(V) ] , hexavalent chromium [ Cr(VI) ] , or a combination of both metals . Mice were sacrificed 2 days after treatment to collect bronchoalveolar lavage fluid and lung tissue samples . Inflammation , cytotoxicity , apoptosis , and oxidative stress markers were measured . Our results indicated that administration of Cr(VI) alone or in combination with As(V) induced neutrophil-dominant inflammation as well as phosphorylation of mitogen-activated protein kinases ; effects of treatment with As(V) alone were comparatively less potent . By analyzing the production of interleukin-6 and activity of lactate dehydrogenase and caspase , we confirmed that co-treatment intensified pulmonary injury and that it was accompanied by oxidative stress , as confirmed by marked increases in the production of reactive oxygen species , reduced glutathione content , and thioredoxin reductase ( TRXRD ) activity . Expressed mRNA levels of heme oxygenase-1 , glutamylcysteine ligase , glutathione peroxidase 2 , thioredoxin ( TRX ) 1 , and TRXRD1 were also enhanced by co-treatment , whereas treatment with As(V) alone reduced the mRNA expression level of TRX2 . Our data suggest that co-treatment with As(V) exacerbated Cr(VI)-induced pulmonary injury and that this effect may be exerted through a disruption in the balance among several antioxidant genes .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
19895865
|
The role of estrogen receptor beta ( ERβ ) in breast cancer is unclear . ERβ is considered to have a protective role in breast cancer development based on findings demonstrating that ERβ expression inhibits ERα-mediated proliferation of breast cancer cells . We previously demonstrated that ERβ causes a ligand independent G2 cell cycle arrest in MCF-7 cells . To study the mechanisms of the ERβ-mediated G2 cell cycle arrest , we investigated its effects on the regulatory pathways responsible for the G2/M phase transition . We found that ERβ inhibits CDK1 activity , which is the critical determinant of the G2/M progression . CDK1 activity is modulated by both stimulatory and inhibitory factors . Cyclin B1 is the major activator of CDK1 . ERβ inhibited the cell cycle-dependent stimulation of cyclin B1 mRNA and protein . GADD45A and BTG2 are two major inhibitors of CDK1 , which have been implicated in breast tumor formation . Based on these findings , we explored if the expression pattern of GADD45A and BTG2 is affected by ERβ . We found that ERβ stimulates GADD45A and BTG2 mRNA levels . The induction of these two genes is caused by ERβ binding directly to these genes and recruiting c-jun and NCOA2 . Our findings demonstrated that unliganded ERβ causes a G2 cell cycle arrest by inactivating CDK1 through the repression of cyclin B1 and stimulation of GADD45A and BTG2 expression . These results provide evidence that drugs that stimulate the production of unliganded ERβ may be effective new therapies to prevent breast cancer .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
21120602
|
OBJECTIVE To investigate the effects of CdTe QDs ( cadmium telluride quantum dots ) on oxidative stress and DNA damage of liver cells in mice . METHODS Thirty ICR male mice were randomly divided into 5 groups : one negative control ( normal saline ) group . Three CdTe QDs groups ( exposed by intravenous injection of 0.2 ml of CdTe QDs at the concentration of 3.75 , 37.5 and 375 nmol/ml respectively ) for electron paramagnetic resonance ( EPR ) test , and another positive control group ( exposed by intravenous injection of 0.2 ml of cyclophosphamide 20 mg/ml ) for single cell gel electrophoresis ( SCGE ) test . All mice were decapitated 24h after the injection , free radicals and DNA damage of liver cells were detected by EPR and SCGE . RESULTS The levels of oxygen free radicals detected by EPR were increased with the increase of CdTe QDs . The tail length , olive tail moment , tail DNA ( % ) and the ratio of tail/head examined by SCGE were also increased with the increase of the dosage of CdTe QDs ( P < 0.01 ) . CONCLUSION CdTe QDs could induce oxidative stress and DNA damage of liver cells in mice with a dose-effect relationship .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
1
] |
22443054
|
Identifying genomic alterations driving breast cancer is complicated by tumor diversity and genetic heterogeneity . Relevant mouse models are powerful for untangling this problem because such heterogeneity can be controlled . Inbred Chaos3 mice exhibit high levels of genomic instability leading to mammary tumors that have tumor gene expression profiles closely resembling mature human mammary luminal cell signatures . We genomically characterized mammary adenocarcinomas from these mice to identify cancer-causing genomic events that overlap common alterations in human breast cancer . Chaos3 tumors underwent recurrent copy number alterations ( CNAs ) , particularly deletion of the RAS inhibitor Neurofibromin 1 ( Nf1 ) in nearly all cases . These overlap with human CNAs including NF1 , which is deleted or mutated in 27.7% of all breast carcinomas . Chaos3 mammary tumor cells exhibit RAS hyperactivation and increased sensitivity to RAS pathway inhibitors . These results indicate that spontaneous NF1 loss can drive breast cancer . This should be informative for treatment of the significant fraction of patients whose tumors bear NF1 mutations .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22851646
|
Prohibiting angiogenesis is an important therapeutic approach for fighting cancer and other angiogenic related diseases . Research focused on proteins that regulate abnormal angiogenesis has attracted intense interest in both academia and industry . Such proteins are able to target several angiogenic factors concurrently , thereby increasing the possibility of therapeutic success . Aquaporin-1 ( AQP1 ) is a water channel membrane protein that promotes tumour angiogenesis by allowing faster endothelial cell migration . In this study we test the hypothesis that AQP1 inhibition impairs tumour growth in a mouse model of melanoma . After validating the inhibitor efficacy of two different AQP1 specific siRNAs in cell cultures , RNA interference experiments were performed by intratumoural injections of AQP1 siRNAs in mice . After 6 days of treatment , AQP1 siRNA treated tumours showed a 75 % reduction in volume when compared to controls . AQP1 protein level , in AQP1 knockdown tumours , was around 75 % that of the controls and was associated with a significant 40 % reduced expression of the endothelial marker , Factor VIII . Immunofluorescence analysis of AQP1 siRNA treated tumours showed a significantly lower microvessel density . Time course experiments demonstrated that repeated injections of AQP1 siRNA over time are effective in sustaining the inhibition of tumour growth . Finally , we have confirmed the role of AQP1 in sustaining an active endothelium during angiogenesis and we have shown that AQP1 reduction causes an increase in VEGF levels . In conclusion , this study validates AQP1 as a pro-angiogenic protein , relevant for the therapy of cancer and other angiogenic-related diseases such as psoriasis , endometriosis , arthritis and atherosclerosis .
|
[
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
] |
23197380
|
The Alternative Lengthening of Telomeres ( ALT ) pathway is a telomerase-independent pathway for telomere maintenance that is active in a significant subset of human cancers and in vitro immortalized cell lines . ALT is thought to involve templated extension of telomeres through homologous recombination , but the genetic or epigenetic changes that unleash ALT are not known . Recently , mutations in the ATRX/DAXX chromatin remodeling complex and histone H3.3 were found to correlate with features of ALT in pancreatic neuroendocrine cancers , pediatric glioblastomas , and other tumors of the central nervous system , suggesting that these mutations might contribute to the activation of the ALT pathway in these cancers . We have taken a comprehensive approach to deciphering ALT by applying genomic , molecular biological , and cell biological approaches to a panel of 22 ALT cell lines , including cell lines derived in vitro . Here we show that loss of ATRX protein and mutations in the ATRX gene are hallmarks of ALT-immortalized cell lines . In addition , ALT is associated with extensive genome rearrangements , marked micronucleation , defects in the G2/M checkpoint , and altered double-strand break ( DSB ) repair . These attributes will facilitate the diagnosis and treatment of ALT positive human cancers .
|
[
0,
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0,
1,
1,
1,
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0,
0,
0
] |
22829774
|
BACKGROUND AND AIMS breast reconstruction with silicone prosthesis following nipple-sparing mastectomy has become widely accepted as a reconstruction option in women requiring mastectomy for cancer . The purpose of this study was to evaluate the incidence and some factors influencing early local complications in patients undergoing NSM with immediate implant reconstruction . MATERIAL AND METHODS prospective study was performed on a consecutive series of 214 breast reconstructions in 205 patients . All complications during the six weeks after surgery were recorded. 42 prostheses were implanted after neoadjuvant chemotherapy , 27 patients previously had radiotherapy due to breast conserving surgery and in all other cases surgery was the pri-mary treatment for cancer . RESULTS the overall six-week complication rate was 16% ( 35 ) and included : major skin flap necrosis ( 4% , 9 procedures ) , minor skin necrosis ( 3% , 7 ) , major infection ( 2% , 5 ) , minor infection ( 3% , 7 ) , prolonged seroma formation ( 3% , 6 ) , haematoma ( 1% , 2 ) and epidermolysis ( 1% , 2 ) . In 6% ( 12 ) reconstruction procedures explantation of prosthesis was done . Neoadjuvant chemo-therapy and radiotherapy were not associated with higher rate of complications . CONCLUSION nipple-sparing mastectomy with immediate implant reconstruction has acceptable morbidity rate in the hand of experienced oncoplastic surgeon and therefore should be considered as treatment option to women requiring mastectomy .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
21044925
|
Exposure of cells to UV light from the sun causes the formation of pyrimidine dimers in DNA that have the potential to lead to mutation and cancer . In humans , pyrimidine dimers are removed from the genome in the form of nt-long oligomers by concerted dual incisions . Though nearly 50 y of excision repair research has uncovered many details of UV photoproduct damage recognition and removal , the fate of the excised oligonucleotides and , in particular , the ultimate fate of the chemically very stable pyrimidine dimers remain unknown . Physiologically relevant UV doses introduce hundreds of thousands of pyrimidine dimers in diploid human cells , which are excised from the genome within h . Once removed from the genome , " where do all the dimers go? " In a recent study we addressed this question . Although our study did not determine the fate of the dimer itself , it revealed that the excised is released from the duplex in a tight complex with the transcription/repair factor TFIIH . This finding combined with recent reports that base and oligonucleotide products of the base and double-strand break repair pathways also make stable complexes with the cognate repair enzymes , and that these complexes activate the MAP kinase and checkpoint signaling pathways , respectively , raises the possibility that TFIIH-30-mer excision complexes may play a role in signaling reactions in response to UV damage .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22825251
|
We have recently proposed a new two-compartment model for understanding the Warburg effect in tumor metabolism . In this model , glycolytic stromal cells produce mitochondrial fuels ( L-lactate and ketone bodies ) that are then transferred to oxidative epithelial cancer cells , driving OXPHOS and mitochondrial metabolism . Thus , stromal catabolism fuels anabolic tumor growth via energy transfer . We have termed this new cancer paradigm the " reverse Warburg effect, " because stromal cells undergo aerobic glycolysis , rather than tumor cells . To assess whether this mechanism also applies during cancer cell metastasis , we analyzed the bioenergetic status of breast cancer lymph node metastases , by employing a series of metabolic protein markers . For this purpose , we used MCT4 to identify glycolytic cells . Similarly , we used TO MM20 and COX staining as markers of mitochondrial mass and OXPHOS activity , respectively . Consistent with the " reverse Warburg effect, " our results indicate that metastatic breast cancer cells amplify oxidative mitochondrial metabolism ( OXPHOS ) and that adjacent stromal cells are glycolytic and lack detectable mitochondria . Glycolytic stromal cells included cancer-associated fibroblasts , adipocytes and inflammatory cells . Double labeling experiments with glycolytic ( MCT4 ) and oxidative ( TO MM20 or COX ) markers directly shows that at least two different metabolic compartments co-exist , side-by-side , within primary tumors and their metastases . Since cancer-associated immune cells appeared glycolytic , this observation may also explain how inflammation literally " fuels " tumor progression and metastatic dissemination , by " feeding " mitochondrial metabolism in cancer cells . Finally , MCT4(+) and TO MM20(-) " glycolytic " cancer cells were rarely observed , indicating that the conventional " Warburg effect " does not frequently occur in cancer-positive lymph node metastases .
|
[
1,
0,
1,
0,
0,
0,
0,
0,
0,
1
] |
22395432
|
A distinct group of breast cancers , called " basal " or " triple-negative " ( TN ) cancers express both basal cytokeratins and the epidermal growth factor receptor , but fail to express estrogen receptors , progesterone receptors or HER2 and have stem-like or mesenchymal features . They are particularly aggressive , are frequently chemo-resistant , with p53 mutation , up-regulation of IL-6 and Stat3 . Because TN cells are particularly sensitive to the anti-diabetic agent metformin , we hypothesized that it may target JAK2/Stat3 signaling . The effects of metformin upon Stat3 expression and activation were examined in four human TN cell lines . Metformin's effects were also studied in sublines with forced over-expression of constitutively active ( CA ) Stat3 , as well as lines with stable knockdown of Stat3 . Metformin inhibited Stat3 activation ( P-Stat3 ) at Tyr705 and Ser727 and downstream signaling in each of the four parental cell lines . CA-Stat3 transfection attenuated , whereas Stat3 knockdown enhanced , the effects of metformin upon growth inhibition and apoptosis induction . A Stat3 specific inhibitor acted synergistically with metformin in reducing cell growth and inducing apoptosis . An mTOR inhibitor showed no significant interaction with metformin . In summary , Stat3 is a critical regulator of metformin action in TN cancer cells , providing the potential for enhancing metformin's efficacy in the clinical setting .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
22189713
|
AIMS Currently , testing for mismatch repair deficiency in colorectal cancers is initiated by performing immunohistochemistry with four antibodies ( MLH1 , PMS2 , MSH2 and MSH6 ) . If any one of these stains is negative the tumour is considered microsatellite unstable and , if clinical circumstances warrant it , the patient is offered genetic testing for Lynch's syndrome . Due to the binding properties of the mismatch repair heterodimer complexes , gene mutation and loss of MLH1 and MSH2 invariably result in the degradation of PMS2 and MSH6 , respectively , but the converse is not true . We propose that staining for PMS2 and MSH6 alone will be sufficient to detect all cases of mismatch repair deficiency and should replace routine screening with all four antibodies . METHODS The electronic database of the department of Anatomical Pathology , Royal North Shore Hospital , Sydney , Australia , was searched for all colorectal carcinomas on which a four panel immunohistochemical microsatellite instability screen was performed . An audit of the slides for concordant loss of MLH1-PMS2 and MSH2-MSH6 was then undertaken . Unusual or discordant cases were reviewed and , in some cases , re-stained to confirm the staining pattern . RESULTS Of 344 cases of colorectal cancer which underwent four antibody immunohistochemistry , 104 displayed loss of at least one mismatch repair protein . Of these , 100 showed concordant mismatch repair loss ( i.e. , loss of MLH1 and PMS2 or loss of MSH2 and MSH6 ) . The four discordant cases comprised two single negative cases ( 1 MSH6 negative/MSH2 positive case , 1 PMS2 negative/MLH1 positive ) and two triple negative ( both MLH1/PMS2/MSH6 negative ) . The microsatellite instability ( MSI ) group showed a relatively high median age ( 69.3 years ) due to the departmental policy of testing all cases with possible MSI morphology regardless of age . CONCLUSIONS The sensitivity and specificity of a two panel test comprised of PMS2 and MSH6 , compared to a four panel test , is 100% . No false negatives or positives were identified . We conclude that the two panel test should replace a four panel protocol for immunohistochemical screening for mismatch repair deficiency .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20632815
|
Lipoprotein lipase ( LPL ) plays a central role in normal lipid metabolism as the key enzyme involved in the hydrolysis of triglycerides present in chylomicrons and very low density lipoproteins . LPL is a member of a family of hydrolytic enzymes that include hepatic lipase and pancreatic lipase . Based on primary sequence homology of LPL to pancreatic lipase , Ser-132 , Asp-156 , and His-241 have been proposed to be part of a domain required for normal enzymic activity . We have analyzed the role of these potential catalytic residues by site-directed mutagenesis and expression of the mutant LPL in human embryonic kidney-293 cells . Substitution of Ser-132 , Asp-156 , and His-241 by several different residues resulted in the expression of an enzyme that lacked both triolein and tributyrin esterase activities . Mutation of other conserved residues , including Ser-97 , Ser-307 , Asp-78 , Asp-371 , Asp-440 , His-93 , and His-439 resulted in the expression of active enzymes . Despite their effect on LPL activity , substitutions of Ser-132 , Asp-156 , and His-241 did not change either the heparin affinity or lipid binding properties of the mutant LPL . In summary , mutation of Ser-132 , Asp-156 , and His-241 specifically abolishes total hydrolytic activity without disrupting other important functional domains of LPL . These combined results strongly support the conclusion that Ser-132 , Asp-156 , and His-241 form the catalytic triad of LPL and are essential for LPL hydrolytic activity .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
1371284
|
A 34-year-old Japanese woman presented with left supraclavicular lymph node swelling . Computed tomography scans revealed a mass on the left lower lobe , pulmonary nodules , and pleural effusion . A lymph node biopsy revealed large-cell carcinoma with an epidermal growth factor receptor ( EGFR ) deletion mutation , L747-T751 in exon 19 . Although malignant pleural effusions carried the same EGFR mutation , progressive pleural effusions after treatment with chemotherapy , gefitinib , and erlotinib did not show any EGFR mutation . A cell line established from the pleural effusion 3 days before the patient expired also did not harbor the EGFR mutation . Histological sections of the lymph node of the patient were similar to those of the xenograft tumor of the cell line . There may be genetic heterogeneity in EGFR mutant tumors .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
1,
0
] |
22835516
|
BACKGROUND Hepatocellular carcinoma ( HCC ) is the most common liver cancer . Therapeutic results are usually unsatisfactory because liver tumors recur often . Immunologic factors may be related to the recurrence of HCC ; however , this possibility is mentioned only rarely . METHODS Thirty HCC patients undergoing hepatectomies were divided into 3 groups according to the diameters of their HCCs : group A ( n = 8 ) , diameter ≤3 cm ; group B ( n = 8 ) , diameter >3 cm and ≤5 cm ; and group C ( n = 14 ) , diameter >5 cm . T-lymphocytes from peripheral blood , nontumor liver tissue , and the HCC were analyzed . RESULTS The percentage of CD25+ in the CD4+ T cells did not differ between the peripheral blood and the nontumor liver tissue among the 3 groups . CD25+ cells were increased in the tumor tissue in group C patients ( range , 6-41% ; median , 22.9% ; P = .003 ) , compared to group A patients . The percentage of CD25+ in the CD4+ T cells in tumor tissue was positively correlated with tumor sizes ( r = 0.556 ) . These CD4+ CD25+ lymphocytes produced transforming growth factor-β and interferon-γ but not interleukin-10 , and were anergic to plate-coated monoclonal antibodies ( anti-CD3/anti-CD28 ) . The characteristics of these antibodies were comparable to those of regulatory T cells . When the infiltration lymphocytes including CD4+ CD25+ T cells were added to the mixed lymphocyte reaction activated by autologous tumor lysate-pulsed dendritic cells , the proliferation of lymphocytes was inhibited . CONCLUSION The increase of CD4+ CD25+ T cells in the tumor microenvironment correlates with tumor sizes . These CD4+ CD25+ regulatory T cells appeared to suppress the immune response activated by dendritic cells .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
21975289
|
Topoisomerase inhibitors such as camptothecin and etoposide are used as anti-cancer drugs and induce double-strand breaks ( DSBs ) in genomic DNA in cycling cells . These DSBs are often covalently bound with polypeptides at the 3 ' and 5 ' ends . Such modifications must be eliminated before DSB repair can take place , but it remains elusive which nucleases are involved in this process . Previous studies show that CtIP plays a critical role in the generation of 3 ' single-strand overhang at " clean " DSBs , thus initiating homologous recombination ( HR)-dependent DSB repair . To analyze the function of CtIP in detail , we conditionally disrupted the CtIP gene in the chicken DT40 cell line . We found that CtIP is essential for cellular proliferation as well as for the formation of 3 ' single-strand overhang , similar to what is observed in DT40 cells deficient in the Mre11/Rad50/Nbs1 complex . We also generated DT40 cell line harboring CtIP with an alanine substitution at residue Ser332 , which is required for interaction with BRCA1 . Although the resulting CtIP(S332A/-/-) cells exhibited accumulation of RPA and Rad51 upon DNA damage , and were proficient in HR , they showed a marked hypersensitivity to camptothecin and etoposide in comparison with CtIP(+/-/-) cells . Finally , CtIP(S332A/-/-)BRCA1(-/-) and CtIP(+/-/-)BRCA1(-/-) showed similar sensitivities to these reagents . Taken together , our data indicate that , in addition to its function in HR , CtIP plays a role in cellular tolerance to topoisomerase inhibitors . We propose that the BRCA1-CtIP complex plays a role in the nuclease-mediated elimination of oligonucleotides covalently bound to polypeptides from DSBs , thereby facilitating subsequent DSB repair .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
20107609
|
Nonmelanoma skin cancer ( NMSC ) is by far the most frequent type of cancer in humans . NMSC includes several types of malignancies with different clinical outcomes , the most frequent being basal and squamous cell carcinomas . We have used the Sleeping Beauty transposon/transposase system to identify somatic mutations associated with NMSC . Transgenic mice bearing multiple copies of a mutagenic Sleeping Beauty transposon T2Onc2 and expressing the SB11 transposase under the transcriptional control of regulatory elements from the keratin K5 promoter were treated with TPA , either in wild-type or Ha-ras mutated backgrounds . After several weeks of treatment , mice with transposition developed more malignant tumors with decreased latency compared with control mice . Transposon/transposase animals also developed basal cell carcinomas . Genetic analysis of the transposon integration sites in the tumors identified several genes recurrently mutated in different tumor samples , which may represent novel candidate cancer genes . We observed alterations in the expression levels of some of these genes in human tumors . Our results show that inactivating mutations in Notch1 and Nsd1 , among others , may have an important role in skin carcinogenesis .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22832494
|
Pterostilbene , a polyphenolic compound present in grapes and other fruits , has been demonstrated to inhibit growth and induce apoptosis and autophagy in some cancer cell types . We found that pterostilbene at the IC90 concentration of 44 �M inhibited proliferation and induced apoptosis in MOLT4 human leukemia cells . Treatment with pterostilbene resulted in a transient accumulation of cells in the G0/G1-cell cycle phase followed by the S-phase arrest . Pterostilbene-induced apoptotic death of MOLT4 cells was mediated by caspase-3 activation and was accompanied by the disruption of mitochondrial membrane potential , phosphatidylserine externalization and internucleosomal DNA fragmentation . Our results suggest that pterostilbene could serve as a potential additional chemotherapeutic agent for the treatment of leukemia .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
23264221
|
The innate immune response involves a variety of inflammatory reactions that can result in inflammatory disease and cancer if they are not resolved and instead are allowed to persist . The effective activation and resolution of innate immune responses relies on the production and posttranscriptional regulation of mRNAs encoding inflammatory effector proteins . The RNA-binding protein HuR binds to and regulates such mRNAs , but its exact role in inflammation remains unclear . Here we show that HuR maintains inflammatory homeostasis by controlling macrophage plasticity and migration . Mice lacking HuR in myeloid-lineage cells , which include many of the cells of the innate immune system , displayed enhanced sensitivity to endotoxemia , rapid progression of chemical-induced colitis , and severe susceptibility to colitis-associated cancer . The myeloid cell-specific HuR-deficient mice had an exacerbated inflammatory cytokine profile and showed enhanced CCR2-mediated macrophage chemotaxis . At the molecular level , activated macrophages from these mice showed enhancements in the use of inflammatory mRNAs ( including Tnf , Tgfb , Il10 , Ccr2 , and Ccl2 ) due to a lack of inhibitory effects on their inducible translation and/or stability . Conversely , myeloid overexpression of HuR induced posttranscriptional silencing , reduced inflammatory profiles , and protected mice from colitis and cancer . Our results highlight the role of HuR as a homeostatic coordinator of mRNAs that encode molecules that guide innate inflammatory effects and demonstrate the potential of harnessing the effects of HuR for clinical benefit against pathologic inflammation and cancer .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
22201685
|
Therapy-induced cellular senescence ( TCS ) , characterized by prolonged cell cycle arrest , is an in vivo response of human cancers to chemotherapy and radiation . Unfortunately , TCS is reversible for a subset of senescent cells , leading to cellular reproliferation and ultimately tumor progression . This invariable consequence of TCS recapitulates the clinical treatment experience of patients with advanced cancer . We report the findings of a clinicopathological study in patients with locally advanced non-small cell lung cancer demonstrating that marker of in vivo TCS following neoadjuvant therapy prognosticate adverse clinical outcome . In our efforts to elucidate key molecular pathways underlying TCS and cell cycle escape , we have previously shown that the deregulation of mitotic kinase Cdk1 and its downstream effectors are important mediators of survival and cell cycle reentry . We now report that aberrant expression of Cdk1 interferes with apoptosis and promotes the formation of polyploid senescent cells during TCS . These polyploid senescent cells represent important transition states through which escape preferentially occurs . The Cdk1 pathway is in part modulated differentially by p21 and p27 two members of the KIP cyclin-dependent kinase inhibitor family during TCS . Altogether , these studies underscore the importance of TCS in cancer therapeutics .
|
[
0,
0,
0,
1,
0,
0,
0,
1,
0,
0
] |
22945332
|
PURPOSE We describe the anticancer activity of ganetespib , a novel non-geldanamycin heat shock protein 90 ( HSP90 ) inhibitor , in non-small cell lung cancer ( NSCLC ) models . EXPERIMENTAL DESIGN The activity of ganetespib was compared with that of the geldanamycin 17-AAG in biochemical assays , cell lines , and xenografts , and evaluated in an ERBB2 YVMA-driven mouse lung adenocarcinoma model . RESULTS Ganetespib blocked the ability of HSP90 to bind to biotinylated geldanamycin and disrupted the association of HSP90 with its cochaperone , p23 , more potently than 17-AAG . In genomically defined NSCLC cell lines , ganetespib caused depletion of receptor tyrosine kinases , extinguishing of downstream signaling , inhibition of proliferation and induction of apoptosis with IC(50) values ranging 2 to 30 nmol/L , substantially lower than those required for 17-AAG ( 20-3,500 nmol/L ) . Ganetespib was also approximately 20-fold more potent in isogenic Ba/F3 pro-B cells rendered IL-3 independent by expression of EGFR and ERBB2 mutants . In mice bearing NCI-H1975 ( EGFR L858R/T790M ) xenografts , ganetespib was rapidly eliminated from plasma and normal tissues but was maintained in tumor with t(1/2) 58.3 hours , supporting once-weekly dosing experiments , in which ganetespib produced greater tumor growth inhibition than 17-AAG . However , after a single dose , reexpression of mutant EGFR occurred by 72 hours , correlating with reversal of antiproliferative and proapoptotic effects . Consecutive day dosing resulted in xenograft regressions , accompanied by more sustained pharmacodynamic effects . Ganetespib also showed activity against mouse lung adenocarcinomas driven by oncogenic ERBB2 YVMA . CONCLUSIONS Ganetespib has greater potency than 17-AAG and potential efficacy against several NSCLC subsets , including those harboring EGFR or ERBB2 mutation .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22806877
|
Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase ( MMP ) enzymes which facilitate invasion . Oleuropein , the main olive oil polyphenol , has anti-proliferative effects . This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line . We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction ( RT-PCR ) in treated and untreated cells . This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells . We found that TIMP1,-3 , and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells , while MMP2 and MMP9 genes were down-regulated , at least initially . Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23167379
|
Modeling the behavior of mammalian arachnoid cells is critical to understand hydrocephalus and other brain disorders involving abnormal flow of cerebrospinal fluid , yet relatively little is known about the physiology of arachnoid cells due to lack of a robust three-dimensional model system . Explanted primary cultures have been the only option to study transport across arachnoid cell membranes , but practical limitations of primary culture include slow growth , early senescence , and poor reproducibility . The purpose of this study was to create immortalized rat arachnoid cell lines to permit in vitro study of arachnoid granulations and properties of cerebrospinal fluid ( CSF ) flow . We established and partially characterized two immortalized cell lines generated from primary rat arachnoid cells , using retroviral gene transfer of SV40 large T antigen ( SV40 LTAg ) either with or without human telomerase ( hTERT ) . The established cell lines stably express either SV40 LTAg alone , or SV40 LTAg and hTERT , and demonstrate high proliferative rate , contact inhibition at confluence , and stable expression of protein markers characteristic of native arachnoid cells over more than 160 passages .
|
[
0,
0,
0,
1,
1,
0,
0,
0,
0,
0
] |
21195136
|
Chromosomal translocations typically impair cell differentiation and often require secondary mutations for malignant transformation . However , the role of a primary translocation in the development of collaborating mutations is debatable . To delineate the role of leukemic translocation NUP98-HOXD13 ( NHD13 ) in secondary mutagenesis , DNA break and repair mechanisms in stimulated mouse B lymphocytes expressing NHD13 were analyzed . Our results showed significantly reduced expression of non-homologous end joining ( NHEJ)-mediated DNA repair genes , DNA Pkcs , DNA ligase4 , and Xrcc4 leading to cell cycle arrest at G2/M phase . Our results showed that expression of NHD13 fusion gene resulted in impaired NHEJ-mediated DNA break repair .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
1,
0
] |
23131583
|
The tumor suppressors Lats1 and Lats2 are mediators of the Hippo pathway that regulates tissue growth and proliferation . Their N-terminal non-kinase regions are distinct except for Lats conserved domains 1 and 2 ( LCD1 and LCD2 ) , which may be important for Lats1/2-specific functions . Lats1 knockout mice were generated by disrupting the N-terminal region containing LCD1 ( Lats1(\u0394N/\u0394N) ) . Some Lats1(\u0394N/\u0394N) mice were born safely and grew normally . However , mouse embryonic fibroblasts ( MEFs ) from Lats1(\u0394N/\u0394N) mice displayed mitotic defects , centrosomal overduplication , chromosomal misalignment , multipolar spindle formation , chromosomal bridging and cytokinesis failure . They also showed anchorage-independent growth and continued cell cycles and cell growth , bypassing cell-cell contact inhibition similar to tumor cells . Lats1(\u0394N/\u0394N) MEFs produced tumors in nude mice after subcutaneous injection , although the tumor growth rate was much slower than that of ordinary cancer cells . Yap , a key transcriptional coactivator of the Hippo pathway , was overexpressed and stably retained in Lats1(\u0394N/\u0394N) MEFs in a cell density independent manner , and Lats2 mRNA expression was downregulated . In conclusion , N-terminally truncated Lats1 induced Lats2 downregulation and Yap protein accumulation , leading to chromosomal instability and tumorigenesis .
|
[
0,
0,
0,
0,
1,
1,
0,
0,
1,
0
] |
23230145
|
The G protein-coupled human gastrin-releasing peptide receptor ( hGRP-R ) is frequently found aberrantly expressed in human cancers of the colon , stomach , and lung , and its ligand-specific activation has been implicated in cell proliferation and differentiation . Here , we demonstrated hGRP-R activation stimulated sustained cyclic AMP response element binding protein ( CREB ) phosphorylation and transactivation in duodenal cancer cells through a protein kinase C and partially p38 mitogen-activated protein kinase-dependent pathway . In contrast , intracellular calcium , ERK1/2 , protein kinase A , and PI3 kinase were not involved . This novel signaling mechanism might be of importance for regulation of CREB-dependent gene expression in human cancer expressing functional hGRP-R .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
12220644
|
Cardiac \u03b1-tropomyosin ( Tm ) single-site mutations D175N and E180G cause familial hypertrophic cardiomyopathy ( FHC ) . Previous studies have shown that these mutations increase both Ca(2+) sensitivity and residual contractile activity at low Ca(2+) concentrations , which causes incomplete relaxation during diastole resulting in hypertrophy and sarcomeric disarray . However , the molecular basis for the cause and the difference in the severity of the manifested phenotypes of disease are not known . In this work we have ( 1 ) used ATPase studies using reconstituted thin filaments in solution to show that these FHC mutants result in an increase in Ca(2+) sensitivity and an increased residual level of ATPase , ( 2 ) shown that both FHC mutants increase the rate of cleavage at R133 , residues N-terminal to the mutations , when free and bound to actin , ( 3 ) shown that for Tm-E180G , the increase in the rate of cleavage is greater than that for D175N , and ( 4 ) shown that for E180G , cleavage also occurs at a new site 53 residues C-terminal to E180G , in parallel with cleavage at R133 . The long-range decreases in dynamic stability due to these two single-site mutations suggest increases in flexibility that may weaken the ability of Tm to inhibit activity at low Ca(2+) concentrations for D175N and to a greater degree for E180G , which may contribute to differences in the severity of FHC .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22794249
|
The authors examined nutritional risk factors for prostate cancer among 9,559 participants in the Prostate Cancer Prevention Trial ( United States and Canada , 1994-2003 ) . The presence or absence of cancer was determined by prostate biopsy , which was recommended during the trial because of an elevated prostate-specific antigen level or an abnormal digital rectal examination and was offered to all men at the trial's end . Nutrient intake was assessed using a food frequency questionnaire and a structured supplement-use questionnaire . Cancer was detected in 1,703 men ; 127 cancers were high-grade ( Gleason score 8-10 ) . There were no associations of any nutrient or supplement with prostate cancer risk overall . Risk of high-grade cancer was associated with high intake of polyunsaturated fats ( quartile 4 vs. quartile 1 : odds ratio = 2.41 , 95% confidence interval ( CI ) : 1.33 , 4.38 ) . Dietary calcium was positively associated with low-grade cancer but inversely associated with high-grade cancer ( for quartile 4 vs. quartile 1 , odds ratios were 1.27 ( 95% CI : 1.02 , 1.57 ) and 0.43 ( 95% CI : 0.21 , 0.89 ) , respectively ) . Neither dietary nor supplemental intakes of nutrients often suggested for prostate cancer prevention , including lycopene , long-chain n-3 fatty acids , vitamin D , vitamin E , and selenium , were significantly associated with cancer risk . High intake of n-6 fatty acids , through their effects on inflammation and oxidative stress , may increase prostate cancer risk .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
1
] |
20693267
|
DNA double-strand breaks ( DSBs ) in embryonic stem ( ES ) cells are repaired primarily by homologous recombination ( HR ) . The mechanism by which HR is regulated in these cells , however , remains enigmatic . To gain insight into such regulatory mechanisms , we have asked how protein levels of Rad51 , a key component of HR , are controlled in mouse ES cells and mouse embryo fibroblasts ( MEFs ) . The Rad51 protein level is about 15-fold higher in ES cells than in MEFs . The level of Rad51 mRNA , however , is only higher , indicating that the differences in mRNA levels due to rates of transcription or mRNA stability are not sufficient to account for the large difference in the abundance of Rad51 protein . Comparison of Rad51 half-lives between ES cells and MEFs also did not explain the elevated level of Rad51 protein in the ES cells . A comparative assessment of the Rad51 translation level demonstrated that it is translated with much greater efficacy in ES cells than in MEFs . To determine whether this high level of translation in ES cells is a general phenomenon in these cells or whether it is a characteristic of specific proteins , such as those involved with recombination and cell cycle progression , we compared mechanisms that regulate the level of Pcna in ES cells with those that regulate Rad51 . The half-life of Pcna and its rate of synthesis were considerably different from those of Rad51 in ES cells , demonstrating that regulation of Rad51 abundance cannot be generalized to other ES cell proteins and not to proteins involved in DNA replication and cell cycle control . Finally , we show that only a small proportion of the abundant Rad51 protein population is activated under basal conditions in ES cells and recruited to DNA DSBs and/or stalled replication forks .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22705496
|
MDSCs and Tregs play an essential role in the immunosuppressive networks that contribute to tumor-immune evasion . The mechanisms by which tumors promote the expansion and/or function of these suppressive cells and the cross-talk between MDSC and Treg remain incompletely defined . Previous reports have suggested that MDSC may contribute to Treg induction in cancer . Herein , we provide evidence that tumor-induced gr-MDSCs , endowed with the potential of suppressing conventional T Lc , surprisingly impair TGF-β1-mediated generation of CD4(+)CD25(+)FoxP3(+) iTregs . Furthermore , gr-MDSCs impede the proliferation of nTregs without , however , affecting FoxP3 expression . Suppression of iTreg differentiation from na�ve CD4(+) cells by gr-MDSC occurs early in the polarization process , requires inhibition of early T cell activation , and depends on ROS and IDO but does not require arginase 1 , iNOS , NO , cystine/cysteine depletion , PD-1 and PD-L1 signaling , or COX-2 . These findings thus indicate that gr-MDSCs from TB hosts have the unanticipated ability to restrict immunosuppressive Tregs .
|
[
0,
1,
0,
0,
0,
0,
0,
0,
1,
0
] |
22891289
|
Loss of telomeric DNA during cell proliferation may play a role in ageing and cancer . Since telomeres permit complete replication of eukaryotic chromosomes and protect their ends from recombination , we have measured telomere length , telomerase activity and chromosome rearrangements in human cells before and after transformation with SV40 or Ad5 . In all mortal populations , telomeres shortened by approximately 65 bp/generation during the lifespan of the cultures . When transformed cells reached crisis , the length of the telomeric TTAGGG repeats was only approximately 1.5 kbp and many dicentric chromosomes were observed . In immortal cells , telomere length and frequency of dicentric chromosomes stabilized after crisis . Telomerase activity was not detectable in control or extended lifespan populations but was present in immortal populations . These results suggest that chromosomes with short ( TTAGGG)n tracts are recombinogenic , critically shortened telomeres may be incompatible with cell proliferation and stabilization of telomere length by telomerase may be required for immortalization .
|
[
0,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
1582420
|
Ceramide induces cell cycle arrest and apoptotic cell death associated with increased levels of p27(kip1) . The aim of this study was to examine the effects of ceramide on p27(kip1) protein levels as a measure of cell cycle arrest and apoptosis . Results showed that ceramide increased p27(kip1) protein levels through activation of protein phosphatase 2A ( PP2A ) in PC-3 prostate cancer cells . Treatment of cells with the PP2A inhibitor okadaic acid or with PP2A-Cα siRNA inhibited ceramide-induced enhanced p27(kip1) protein expression and Akt dephosphorylation , and prevented Skp2 downregulation . Overexpression of constitutively active Akt attenuated ceramide-induced Skp2 downregulation and p27(kip1) upregulation . In addition , ceramide stimulated binding of the PP2A catalytic subunit PP2A-Cαβ to Akt as assessed by immunoprecipitation experiments , indicating that PP2A is involved in the induction of p27(kip1) via inhibition of Akt pathway . Finally , whether PP2A can regulate p27(kip1) expression independently of Akt pathway was determined . Knockdown of PP2A-Cα with siRNA reduced p27(kip1) levels in the presence of Akt inhibitor . These data reveal that PP2A is a regulator of ceramide-induced p27(kip1) expression via Akt-dependent and Akt-independent pathways .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
1,
0
] |
20954073
|
Tumor invasion and metastasis are the primary causes of cancer patient mortality , underscoring the need for identification of novel genes and signaling pathways that mediate these prognosis-determining phenomena . To identify and characterize novel lung adenocarcinoma genes associated with lung cancer progression , we created a bioinformatics-based approach that focuses on human cell-cycle-regulated genes that have evolved only in higher organisms but not in lower eukaryotic cells . In siRNA experiments in lung cancer cells , FLJ10540 was identified as one of several novel targets involved in cell migration and invasion . Here , we demonstrate that PI3K inhibition affects FLJ10540-mediated cell migration and invasion and further , that FLJ10540 knockdown ablates AKT-Ser(473) phosphorylation . Taken together , these findings indicate that the FLJ10540/PI3K/AKT pathway may harbor new therapeutic targets for treating invasive lung adenocarcinoma .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
20217555
|
Steroid hormone receptors , including estrogen receptor-alpha ( ERalpha ) , are ligand-activated transcription factors , and hormone binding leads to depletion of receptor levels via preteasome-mediated degradation . NEDD8 ( neural precursor cell-expressed developmentally down-regulated ) is an ubiquitin-like protein essential for protein processing and cell cycle progression . We recently demonstrated that ubiquitin-activating enzyme ( Uba)3 , the catalytic subunit of the NEDD8-activating enzyme , inhibits ERalpha transcriptional activity . Here we report that Uba3-mediated inhibition of ERalpha transactivation function is due to increased receptor protein turnover . Coexpression of Uba3 with ERalpha increased receptor degradation by the 26S proteasome . Inhibition of NEDD8 activation and conjugation diminished polyubiquitination of ERalpha and blocked proteasome-mediated degradation of receptor protein . The antiestrogen ICI 182,780 is known to induce ER degradation . In human MCF7 breast cancer cells modified to contain a disrupted NEDD8 pathway , ICI 182,780 degradation of ERalpha was impaired , and the antiestrogen was ineffective at inhibiting cell proliferation . This study provides the first evidence linking nuclear receptor degradation with the NEDD8 pathway and the ubiquitin-proteasome system , suggesting that the two pathways can act together to modulate ERalpha turnover and cellular responses to estrogens . Based on our observation that an intact NEDD8 pathway is essential for the antiproliferation activity of the ICI 182,780 in ERalpha positive breast cancer cells , we propose that disruptions in the NEDD8 pathway provide a mechanism by which breast cancer cells acquire antiestrogen resistance while retaining expression of ERalpha .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
12554766
|
The mechanisms by which tumour cells metastasize and the role that cell polarity proteins play in this process are not well understood . We report that partitioning defective protein 3 ( Par3 ) is dysregulated in metastasis in human breast cancer , and is associated with a higher tumour grade and ErbB2-positive status . Downregulation of Par3 cooperated with ErbB2 to induce cell invasion and metastasis in vivo . Interestingly , the metastatic behaviour was not associated with an overt mesenchymal phenotype . However , loss of Par3 inhibited E-cadherin junction stability , disrupted membrane and actin dynamics at cell-cell junctions and decreased cell-cell cohesion in a manner dependent on the Tiam1/Rac-GTP pathway . Inhibition of this pathway restored E-cadherin junction stability and blocked invasive behaviour of cells lacking Par3 , suggesting that loss of Par3 promotes metastatic behaviour of ErbB2-induced tumour epithelial cells by decreasing cell-cell cohesion .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23263278
|
Pyruvate kinase M2 ( PKM2 ) is a key player in the Warburg effect of cancer cells . However , the mechanisms of regulating PKM2 are not fully elucidated . Here , we identified the protein-serine/threonine kinase PIM2 , a known oncogene , as a novel binding partner of PKM2 . The interaction between PIM2 and PKM2 was confirmed by multiple biochemical approaches in vitro and in cultured cells . Importantly , we found that PIM2 could directly phosphorylate PKM2 on the Thr-454 residue , resulting in an increase of PKM2 protein levels . Compared with wild type , PKM2 with the phosphorylation-defective mutation displayed a reduced effect on glycolysis , co-activating HIF-1\u03b1 and \u03b2-catenin , and cell proliferation , while enhancing mitochondrial respiration of cancer cells . These findings demonstrate that PIM2-dependent phosphorylation of PKM2 is critical for regulating the Warburg effect in cancer , highlighting PIM2 as a potential therapeutic target .
|
[
0,
0,
1,
0,
0,
1,
0,
0,
0,
0
] |
24142698
|
Approximately 50% of human tumors have a mutation in TP53 . The pattern and spectra of TP53 mutations often differ between cancer types , perhaps due to different etiological factors . The Hupki ( human TP53 knock-in ) mouse embryo fibroblast ( HUF ) immortalization assay is useful for studying mutagenesis in the human TP53 gene by environmental carcinogens . Prior to initiating an immortalization assay , carcinogen treatment conditions must be optimized , which can require a large number of cells . As primary HUF cultures senesce within 2 weeks , restricting their use , we investigated whether immortalized HUFs retaining wild-type TP53 can be surrogates for primary HUFs in initial treatment optimization . DNA damage by eight compounds found in diesel exhaust , benzo[a]pyrene , 3-nitrobenzanthrone , 1-nitropyrene , 1,3-dinitropyrene , 1,6-dinitropyrene , 1,8-dinitropyrene , 6-nitrochrysene , and 3-nitrofluorene , was assessed by ( 32 ) P-postlabeling and the alkaline comet assay in primary HUFs and in an immortal HUF cell line J201 . For most compounds , higher levels of DNA adducts accumulated in J201 cells than in primary HUFs . This difference was not reflected in the comet assay or by cell viability changes . Experiments in three additional immortal HUF cell lines ( AAI49 , U56 , and E2-143 ) confirmed strong differences in DNA adduct levels compared with primary HUFs . However , these did not correlate with the protein expression of Nqo1 or Nat1/2 , or with gene expression of Cyp1a1 or Cyp1b1 . Our results show that using immortal HUFs as surrogates for primary HUFs in genotoxicity screening has limitations and that DNA adduct formation is the best measure of genotoxicity of the nitro-polycyclic aromatic hydrocarbons tested in HUFs .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
22351035
|
SWAP-70 , a phosphatidylinositol trisphosphate ( PtdIns(3,4,5)P(3) ) binding protein , has been suggested to be involved in transformation of mouse embryo fibroblasts ( MEFs ) as well as membrane ruffling after growth factor stimulation of the cells . A mutant , SWAP-70-374 , was found to be able to bind to F-actin in vitro , whereas wild-type SWAP-70 failed to do so . This mutant was present at the plasma membrane without any stimulation while the wild-type protein was present only in the cytosol unless cells were stimulated with EGF . Expression of this mutant in MEFs resulted in morphologic transformation , fast growth , and loss of contact inhibition , suggesting that SWAP-70 with this mutation can transform the cells . ERK1/2 was activated in SWAP-70-374-transformed cells . Use of MEK inhibitors revealed that the ERK1/2 pathway does not affect the cell growth of MEFs but is responsible for loss of contact inhibition . To investigate the function of SWAP-70 further , drugs that can inhibit SWAP-70-dependent cell responses were screened . Among various drugs , sanguinarine was found to inhibit transformation of MEFs by SWAP-70-374 . This drug was able to inhibit SWAP-70-mediated membrane ruffling as well , suggesting that its effect was closely related to the SWAP-70 signaling pathway . These results suggest that SWAP-70-374 can activate some signaling pathways , including the ERK1/2 pathway , to transform MEFs .
|
[
0,
0,
0,
0,
1,
0,
0,
0,
0,
0
] |
21152038
|
Extensive biochemical and structural analyses have been performed on the putative DNA repair proteins of hyperthermophilic archaea , in contrast to the few genetic analyses of the genes encoding these proteins . Accordingly , little is known about the repair pathways used by archaeal cells at high temperature . Here , we attempted to disrupt the genes encoding the potential repair proteins in the genome of the hyperthermophilic archaeon Thermococcus kodakaraensis . We succeeded in isolating null mutants of the hjc , hef , hjm , xpb , and xpd genes , but not the radA , rad50 , mre11 , herA , nurA , and xpg/fen1 genes . Phenotypic analyses of the gene-disrupted strains showed that the xpb and xpd null mutants are only slightly sensitive to ultraviolet ( UV ) irradiation , methyl methanesulfonate ( MMS ) and mitomycin C ( MMC ) , as compared with the wild-type strain . The hjm null mutant showed sensitivity specifically to mitomycin C. On the other hand , the null mutants of the hjc gene lacked increasing sensitivity to any type of DNA damage . The Hef protein is particularly important for maintaining genome homeostasis , by functioning in the repair of a wide variety of DNA damage in T. kodakaraensis cells . Deletion of the entire hef gene or of the segments encoding either its nuclease or helicase domain produced similar phenotypes . The high sensitivity of the Δhef mutants to MMC suggests that Hef performs a critical function in the repair process of DNA interstrand cross-links . These damage-sensitivity profiles suggest that the archaeal DNA repair system has processes depending on repair-related proteins different from those of eukaryotic and bacterial DNA repair systems using homologous repair proteins analyzed here .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
21178304
|
PRL induces quiescent Nb2 rat T-lymphoma cells to undergo mitogenesis . Upon PRL stimulation , the transcription factor interferon regulatory factor-1 ( IRF-1 ) is induced as a novel T-cell activation gene in Nb2 cells . Surprisingly , IRF-1 is expressed twice during a single PRL-induced growth cycle : first during the early G1 phase , in an immediate transient peak from 15 min to 2 h , and second during the G1/S phase transition , in a broader peak beginning at 8 h . The unusual biphasic expression of IRF-1 mRNA is accompanied both times by de novo IRF-1 protein synthesis . However , the rate of IRF-1 protein turnover appears to be different in G1 and S phases . IRF-1 protein expressed in G1 exhibits a half-life of about 25 min , whereas in the S phase , the half-life is about 60 min . By washing out PRL at various times during G1 , we found a direct correlation among the length of PRL exposure , the second peak of IRF-1 mRNA expression , and DNA synthesis . Our data suggest that PRL and one putative nuclear mediator , IRF-1 , may be important in two distinct phases of the cell cycle : first in cell cycle activation , and then in S phase progression .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
1491701
|
The cyclin-dependent kinase ( CDK ) inhibitor p21(Waf1/Cip1/Sdi1) was identified initially as a gene induced in senescent cells and itself has been shown to cause permanent growth arrest/senescence . Reactive oxygen species ( ROS ) , a byproduct of oxidative processes , can also induce an irreversible growth arrest similar to senescence . Here we show that p21 increased intracellular levels of ROS both in normal fibroblasts and in p53-negative cancer cells . N-acetyl-L-cysteine , an ROS inhibitor , rescued p21-induced senescence , showing that ROS elevation is necessary for induction of the permanent growth arrest phenotype. p16(Ink4a) , a CDK4- and CDK6-specific inhibitor , failed to increase ROS levels , and cell cycle arrest induced by p16 was reversible following its down-regulation , demonstrating the specificity of this p21 effect . A p21 mutant that lacked the ability to bind proliferating cell nuclear antigen ( PCNA ) retained the ability to induce both ROS and permanent growth arrest . All of these findings establish that p21 mediates senescence by a mechanism involving ROS accumulation which does not require either its PCNA binding or the CDK inhibitory functions shared with p16 .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
1
] |
11980715
|
Epidermal growth factor receptor ( EGFR ) and human epidermal growth factor receptor 2 ( HER2 ) amplification occurs in over 30% of esophageal carcinomas . Combination therapies with EGFR and HER2-targeting agents and cytotoxic agents are considered a potential therapeutic option for esophageal cancer . We evaluated the antitumor effects of lapatinib , a dual tyrosine kinase inhibitor which simultaneously inhibits EGFR and HER2 , 5-fluorouracil ( 5-Fu ) alone and in combination on esophageal cancer cells . The antiproliferative activity of lapatinib , 5-Fu and lapatinib plus 5-Fu was measured by MTT assay and the combination index ( CI ) values were calculated . Additionally , cell cycle distribution of lapatinib alone and the combination with 5-Fu were detected by flow cytometry analysis . AnnexinV-FITC and propidium iodide stain were used for analyzing the apoptotic cells after cells were treated with either agent alone or in combination . The EGFR and HER2 activated signaling pathways were monitored by western blotting . The combination of lapatinib and 5-Fu synergistically inhibited cell proliferation and exhibited an enhanced proapoptotic effect on esophageal cancer cells . The potentiation effect of combined treatment was associated with downregulation of EGFR and HER2 signaling pathways because data from western blot analysis showed that lapatinib in combination with 5-Fu markedly reduced the phosphorylation of EGFR and HER2 , and inhibited the activation of downstream signaling molecules , such as AKT and ERK . A significant G1 arrest was also observed in cell cycle analysis after exposing cells to lapatinib , however , combination with 5-Fu did not enhance G1 arrest . These results indicate that the combination of the lapatinib and 5-Fu is a promising treatment option for esophageal carcinoma with HER2 amplification .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
1,
0
] |
22293713
|
BACKGROUND Neuroblastoma ( NBL ) is a common pediatric solid tumor , and outcomes for patients with advanced neuroblastoma remain poor despite extremely aggressive treatment . Chemotherapy resistance at relapse contributes heavily to treatment failure . The poor survival of patients with high-risk NBL prompted this investigation into novel treatment options with the objective of gaining a better understanding of resistance mechanisms . On the basis of previous work and on data from publicly available studies , the authors hypothesized that human epidermal growth factor receptor 4 ( Her4 ) contributes to resistance . METHODS Her4 expression was reduced with small-hairpin RNA ( shRNA ) to over express intracellular HER4 , and the authors tested its impact on tumor cell survival under various culture conditions . The resulting changes in gene expression after HER4 knockdown were measured by using a messenger RNA ( mRNA ) array . RESULTS HER4 expression was up-regulated in tumor spheres compared with the expression in monolayer culture . With HER4 knockdown , NBL cells became less resistant to anoikis and serum starvation . Moreover , HER4 knockdown increased the chemosensitivity of NBL cells to cisplatin , doxorubicin , etoposide , and activated ifosfamide . In mRNA array analysis , HER4 knockdown predominately altered genes related to cell cycle regulation . In NBL spheres compared with monolayers , cell proliferation was decreased , and cyclin D expression was reduced . HER4 knockdown reversed cyclin D suppression . Overexpressed intracellular HER4 slowed the cell cycle and induced chemoresistance . CONCLUSIONS The current results indicated that HER4 protects NBL cells from multiple exogenous apoptotic stimuli , including anoikis , nutrient deficiency , and cytotoxic chemotherapy . The intracellular fragment of HER4 was sufficient to confer this phenotype . HER4 functions as a cell cycle suppressor , maintaining resistance to cellular stress . The current findings indicate that HER4 overexpression may be associated with refractory disease , and HER4 may be an important therapeutic target .
|
[
0,
0,
0,
0,
1,
0,
0,
1,
1,
0
] |
22415601
|
Escherichia coli pol V ( UmuD'(2)C ) , the main translesion DNA polymerase , ensures continued nascent strand extension when the cellular replicase is blocked by unrepaired DNA lesions . Pol V is characterized by low sugar selectivity , which can be further reduced by a Y11A " steric-gate " substitution in UmuC that enables pol V to preferentially incorporate rNTPs over dNTPs in vitro . Despite efficient error-prone translesion synthesis catalyzed by UmuC_Y11A in vitro , strains expressing umuC_Y11A exhibit low UV mutability and UV resistance . Here , we show that these phenotypes result from the concomitant dual actions of Ribonuclease HII ( RNase HII ) initiating removal of rNMPs from the nascent DNA strand and nucleotide excision repair ( NER ) removing UV lesions from the parental strand . In the absence of either repair pathway , UV resistance and mutagenesis conferred by umuC_Y11A is significantly enhanced , suggesting that the combined actions of RNase HII and NER lead to double-strand breaks that result in reduced cell viability . We present evidence that the Y11A-specific UV phenotype is tempered by pol IV in vivo . At physiological ratios of the two polymerases , pol IV inhibits pol V-catalyzed translesion synthesis ( TLS ) past UV lesions and significantly reduces the number of Y11A-incorporated rNTPs by limiting the length of the pol V-dependent TLS tract generated during lesion bypass in vitro . In a recA730 lexA(Def) \u0394umuDC \u0394dinB strain , plasmid-encoded wild-type pol V promotes high levels of spontaneous mutagenesis . However , umuC_Y11A-dependent spontaneous mutagenesis is only of that observed with wild-type pol V , but increases to of wild-type levels in an isogenic \u0394rnhB strain and of wild-type levels in a \u0394rnhA \u0394rnhB double mutant . Our observations suggest that errant ribonucleotides incorporated by pol V can be tolerated in the E. coli genome , but at the cost of higher levels of cellular mutagenesis .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
23144626
|
The c-Jun NH(2)-terminal kinase ( JNK ) signaling cascade has been implicated in a wide range of diseases , including cancer . It is unclear how different JNK proteins contribute to human cancer . Here , we report that JNK2 is activated in more than 70% of human squamous cell carcinoma ( SCC ) samples and that inhibition of JNK2 pharmacologically or genetically impairs tumorigenesis of human SCC cells . Most importantly , JNK2 , but not JNK1 , is sufficient to couple with oncogenic Ras to transform primary human epidermal cells into malignancy with features of SCC . JNK2 prevents Ras-induced cell senescence and growth arrest by reducing the expression levels of the cell cycle inhibitor p16 and the activation of NF-kappaB . On the other hand , JNK , along with phosphoinositide 3-kinase , is essential for Ras-induced glycolysis , an energy-producing process known to benefit cancer growth . These data indicate that JNK2 collaborates with other oncogenes , such as Ras , at multiple molecular levels to promote tumorigenesis and hence represents a promising therapeutic target for cancer .
|
[
0,
0,
1,
1,
0,
0,
0,
0,
0,
0
] |
20354187
|
A persistent immune response to hepatitis viruses is a well-recognized risk factor for hepatocellular carcinoma . However , the molecular and cellular basis for the procarcinogenic potential of the immune response is not well defined . Here , using a unique animal model of chronic hepatitis that induces hepatocellular carcinogenesis , we demonstrate that neutralization of the activity of Fas ligand prevented hepatocyte apoptosis , proliferation , liver inflammation , and the eventual development of hepatocellular carcinoma . The results indicate that Fas ligand is involved not only in direct hepatocyte killing but also in the process of inflammation and hepatocellular carcinogenesis in chronic hepatitis . This is the first demonstration that amelioration of chronic inflammation by some treatment actually caused reduction of cancer development .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
1
] |
12391022
|
Gadd45a , the first well-defined p53 downstream gene , can be induced by multiple DNA-damaging agents , which plays important roles in the control of cell cycle checkpoint , DNA repair process and signaling transduction . Our previous findings suggested that Gadd45a maintains cell-cell adhesion and cell contact inhibition . However , little is known about how Gadd45a participates in the suppression of malignancy in human cancer cells . To examine the functions of Gadd45a in cell invasion and metastasis , we performed the adhesion , wound-healing and transwell assays in Gadd45a ( +/+ ) and Gadd45a ( -/- ) MEF cell lines . We found the adhesion , migration and invasive abilities were much higher in Gadd45a deficient cells . We furthermore applied high-throughput cDNA microarray analysis and bioinformatics analysis to analyze the mechanisms of Gadd45a gene in invasion and metastasis . Compared with the Gadd45a wild type cells , the Gadd45a deficient cells showed a wide range of transcripts alterations . The altered gene pathways were predicted by the MAS software , which indicated focal adhesion,cell communication,ECM-receptor interaction as the three main pathways . Real-time PCR was employed to validate the differentially expressed genes . Interestingly , we figured out that the deregulations of these genes are caused neither by genomic aberrations nor methylation status . These findings provided a novel insight that Gadd45a may involve in tumor progression by regulating related genes expressions .
|
[
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
] |
22825327
|
The glutathione peroxidases , a family of selenocysteine-containing redox enzymes , play pivotal roles in balancing the signaling , immunomodulatory , and deleterious effects of reactive oxygen species ( ROS ) . The glutathione peroxidase GPX3 is the only extracellular member of this family , suggesting it may defend cells against ROS in the extracellular environment . Notably , GPX3 hypermethylation and underexpression occur commonly in prostate , gastric , cervical , thyroid , and colon cancers . We took a reverse genetics approach to investigate whether GPX3 would augment inflammatory colonic tumorigenesis , a process characterized by oxidative stress and inflammation , comparing Gpx3(-/-) mice in an established two-stage model of inflammatory colon carcinogenesis . Gpx3-deficient mice exhibited an increased tumor number , though not size , along with a higher degree of dysplasia . In addition , they exhibited increased inflammation with redistribution toward protumorigenic M2 macrophage subsets , increased proliferation , hyperactive WNT signaling , and increased DNA damage . To determine the impact of acute gene loss in an established colon cancer line , we silenced GPX3 in human Caco2 cells , resulting in increased ROS production , DNA damage and apoptosis in response to oxidative stress , combined with decreased contact-independent growth . Taken together , our results suggested an immunomodulatory role for GPX3 that limits the development of colitis-associated carcinoma .
|
[
0,
0,
0,
0,
0,
1,
0,
1,
0,
1
] |
23221387
|
The environmental arylamine mutagens are implicated in the etiology of various sporadic human cancers . Arylamine-modified dG lesions were studied in two fully paired 11-mer duplexes with a -G*CN- sequence context , in which G* is a C8-substituted dG adduct derived from fluorinated analogs of 4-aminobiphenyl ( FABP ) , 2-aminofluorene ( FAF ) or 2-acetylaminofluorene ( FAAF ) , and N is either dA or dT . The FABP and FAF lesions exist in a simple mixture of ' stacked ' ( S ) and ' B-type ' ( B ) conformers , whereas the N-acetylated FAAF also samples a ' wedge ' ( W ) conformer . FAAF is repaired three to four times more efficiently than FABP and FAF . A simple A- to -T polarity swap in the G*CA/G*CT transition produced a dramatic increase in syn-conformation and resulted in 2- to 3-fold lower nucleotide excision repair ( NER ) efficiencies in Escherichia coli . These results indicate that lesion-induced DNA bending/thermodynamic destabilization is an important DNA damage recognition factor , more so than the local S/B-conformational heterogeneity that was observed previously for FAF and FAAF in certain sequence contexts . This work represents a novel 3'-next flanking sequence effect as a unique NER factor for bulky arylamine lesions in E. coli .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
0
] |
23180767
|
Carboxypeptidase M ( CPM ) targets the basic amino acids arginine and lysine present at the C-terminus of peptides or proteins . CPM is thought to be involved in inflammatory processes . This is corroborated by CPM-mediated trimming and modulation of inflammatory factors , and expression of the protease in inflammatory environments . Since the function of CPM in and beyond inflammation remains mainly undefined , the identification of natural substrates can aid in discovering the ( patho)physiological role of CPM . CCL1/I-309 , with its three C-terminal basic amino acids , forms a potential natural substrate for CPM . CCL1 plays a role not only in inflammation but also in apoptosis , angiogenesis and tumor biology . Enzymatic processing differently impacts the biological activity of chemokines thereby contributing to the complex regulation of the chemokine system . The aim of the present study was to investigate whether ( i ) CCL1/I-309 is prone to trimming by CPM , and ( ii ) the biological activity of CCL1 is altered after C-terminal proteolytic processing . CCL1 was identified as a novel substrate for CPM in vitro using mass spectrometry . C-terminal clipping of CCL1 augmented intracellular calcium release mediated by CCR8 but reduced the binding of CCL1 to CCR8 . In line with the higher intracellular calcium release , a pronounced increase of the anti-apoptotic activity of CCL1 was observed in the BW5147 cellular model . CCR8 signaling , CCR8 binding and anti-apoptotic activity were unaffected when CPM was exposed to the carboxypeptidase inhibitor DL-2-mercaptomethyl-3-guanidino-ethylthiopropanoic acid . The results of this study suggest that CPM is a likely candidate for the regulation of biological processes relying on the CCL1-CCR8 system .
|
[
0,
0,
0,
0,
0,
0,
0,
1,
0,
0
] |
22479563
|
Cellular senescence is considered as a tumor suppressive mechanism . Recent evidence indicates however that senescent cells secrete various growth factors and cytokines , some of which may paradoxically promote cancer progression . This phenomenon termed senescence-associated secretory phenotype ( SASP ) must be inhibited in order for anti-proliferative agents to be effective . The present study was designed to determine whether the β-catenin destruction complex ( BCDC ) , known to integrate the action of various growth factors and cytokines , would represent a suitable target to inhibit the activity of SASP components . For this , we carried out experiments to determine the effect of drug-induced senescence on secretion of SASP , β-catenin transactivation , and the relationship between these processes . Moreover , genetic and pharmacological approaches were used to define the implication of BCDC in mediating the effects of SASP components on cell migration and resistance to drugs . The findings indicate that drug-induced senescence was associated with expression of various Wnt ligands in addition to previously known SASP components . Beta catenin transactivation and expression of genes implicated in epithelial-mesenchymal transition ( EMT ) also increased in response to drug-induced SASP . These effects were prevented by Pyrvinium , a recently described activator of BCDC . Pyrvinium also suppressed the effects of SASP on cell migration and resistance to doxorubicin . Together , these findings provide insights on the potential role of BCDC in mediating the effects of drug-induced SASP on cancer cell invasion and resistance to therapy , and suggest that targeting this pathway may represent an effective approach to enhance the activity of current and prospective anti-cancer therapeutics .
|
[
1,
0,
0,
1,
0,
0,
0,
0,
0,
0
] |
23272224
|
To elucidate role of the three enzymes in hepatocarcinogenesis , hMTH1 , hOGG1 and hMYH , mRNA expression were examined by using RT/semi-quantitative real-time PCR and 8-O-HdG levels was studied by HPLC/ECD in HCC and non-tumorous liver tissue of 21 patients with hepatocellular carcinoma ( HCC ) . It was found that the 8-OHdG level in non-tumourous liver tissue was significantly higher than in HCC tissue ( P = 0.006 ) , and this was correlated with the degree of inflammation . The hMTH1 expression in HCC tissue was significantly higher than in non-tumorous liver tissue ( P = 0.014 ) . Inversely , The hMYH alpha expression was significantly increased ( P = 0.039 ) in non-tumorous liver tissue . No difference was seen in hOGG1 expression in non-tumorous liver and HCC tissue . A significant linear correlation between hMTH1 and hOGG1 expression was found both in HCC tissue ( r = 0.809 , P < 0.001 ) and in non-tumorous liver tissue ( r = 0.883 , P < 0.001 ) . Our findings suggested a reactive rather than pathogenic role of the DNA repair enzymes in the hepatocarcinogenesis .
|
[
0,
0,
0,
0,
0,
1,
0,
0,
0,
1
] |
12658805
|
The UT-7 cell line was established from a patient with a megakaryoblastic leukemia ( Komatsu et al , Cancer Res 51 : 341 , 1991 ) . Its proliferation is strictly dependent on the presence of hematopoietic growth factors including erythropoietin ( Epo ) , granulocyte-macrophage colony-stimulating factor ( GM-CSF ) , and interleukin-3 ( IL-3 ) . We investigated the differentiation capacities of this cell line under the action of several growth factors , using immunomarkers , flow cytometry , and ultrastructural techniques . In the presence of GM-CSF and IL-3 , eosinophil and basophil promyelocytes were detected , as well as a few cells with erythroid and megakaryocytic ( MK ) differentiation features . In contrast , Epo induced a marked erythroid differentiation with an increase of glycophorin A expression , accompanied by a few hemoglobinized cells . Differentiation induced by the growth factors took 24 to 48 hours to begin , and increased with cell passages to a plateau at 2 weeks of culture . However , this was not only due to a cell selection because the differential effects of Epo and GM-CSF were observed from a single cell clone and the phenotype could be reversed by opposite growth factors , even after a long period of culture . We subsequently investigated the phenotype of UT-7 in the presence of combinations of Epo , IL-3 , and GM-CSF , and showed that GM-CSF and IL-3 act predominantly over Epo . This effect was mediated by a rapid downmodulation of Epo receptors by GM-CSF at messenger RNA and binding sites levels , without a change in receptor affinities . On the other hand , Epo had no effect on number and affinity of GM-CSF receptors . This study shows that UT-7 is a growth factor-dependent pluripotent cell line in which commitment may be directed by a hierarchical action of growth factors through an early and rapid transmodulation of growth factor receptors .
|
[
0,
0,
0,
0,
0,
0,
0,
0,
1,
0
] |
1467515
|
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