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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The main objective of this study to analyze which of 31 cellular factors (resistance proteins, proliferative factors, apoptotic factors, angiogenic factors, proto-oncogenes) most accurately predict the resistance of non-small cell lung carcinomas. To this purpose, we used a short-term in vitro test that measures changes in the rate at which radioactive nucleic acid precursors are incorporated into tumor cells after the addition of doxorubicin to determine the response to doxorubicin in 94 non-small cell lung carcinomas. The results obtained by the short-term test were related to the various cellular factors which were in turn determined by immunohistochemistry and flow cytometry. A significant correlation was found between the data obtained by the short-term test and the expression of P-glycoprotein 170 (P = 0.00004), glutathione-S-transferase-pi (P = 0.0002), metallothionein (P = 0.0008),
thymidylate synthase
(P = 0.002), O6-methylguanine-DNA-methyltransferase (P = 0.008) and lung resistance-related protein (LRP, P = 0.03). There was only a weak correlation between heat shock proteins (HSP70) and no correlation between the expression of topoisomerase II or catalase and the short-term test results. To measure the proliferative activity, the following were determined: PCNA, cyclin A, cyclin D and cdk2. Only a weak relationship was found between the expression of cdk2 (P = 0.04) and PCNA (P = 0.05) and the doxorubicin response in vitro. Of the investigated pro-apoptotic factors (Fas/CD95, Fas ligand,
caspase-3
), only Fas/CD95 is significantly associated with the drug response (P = 0.007). The apoptotic index also reveals a significant correlation (P = 0.03). Angiogenesis, as measured by the microvessel density and the angiogenic factors, is inversely correlated to the resistance of non-small cell lung cancer. Platelet-derived endothelial cell growth factor (PD-ECGF) and vascular endothelial growth factor (VEGF) exhibit a significant relationship to the drug resistance (P = 0.0006 and P = 0.004, respectively). Of the investigated proto-oncogenes (Fos, Jun, ErbB-1, ErbB-2, Myc, Ras), only ErbB-2 is weakly associated with the in vitro short term test. In order to determine whether combining factors can result in improved predictive information, combinations of the factors (pairs, triplets) were analyzed. The systematic investigation of these combinations yields an improvement in the predictive information. With one factor up to 76.6% of the tumors, with two factors up to 85.4% and with three factors up to 89.5% of the tumors could be correctly diagnosed.
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PMID:Cellular predictive factors for the drug response of lung cancer. 1113 47
Uracil DNA glycosylase (UDG) is a base excision repair enzyme responsible for the removal of uracil present in DNA after cytosine deamination or misincorporation during replication. Inhibition of
thymidylate synthase
(TS), an important target for cancer chemotherapy, leads to deoxythymidine triphosphate (dTTP) pool depletion and elevation of deoxyuridine monophosphate (dUMP) pools which may also result in the accumulation of deoxyuridine triphosphate (dUTP). Large quantities of dUTP are believed to overwhelm the pyrophosphatase dUTPase, leading to misincorporation of uracil into DNA. Uracil is removed from DNA by uracil DNA glycosylase (UDG) resulting in an abasic site, but since the ratio dUTP:dTTP may remain high during continuing TS inhibition uracil can become re-incorporated into DNA causing a futile cycle eventually leading to DNA damage and cell death. This study has used isogenic cell lines differing in their expression of UDG to investigate the role of this enzyme in sensitivity to the specific TS inhibitors, ZD9331 and raltitrexed. The study showed that although increased expression and activity of UDG may lead to increased cell growth inhibition after TS inhibition over the first 24 h of treatment (measured using 3-(4,5-dimethyl (thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), probably due to increased damage to single-stranded DNA, the level of enzyme expression does not affect cell viability or cell death (measured using clonogenic assay, cell counting of attached/detached cells and cleavage of both poly ADP-ribose polymerase (PARP) and
caspase 3
). Increased expression and activity of UDG did not affect sensitivity to TS inhibition at later time points (up to 72 h treatment). Therefore UDG does not appear to play a major role in the response to TS inhibition, at least in the model used, and the results suggest that other determinants of response previously investigated, such as TS and dUTPase, may be more important for the response to TS inhibition.
...
PMID:Expression of uracil DNA glycosylase (UDG) does not affect cellular sensitivity to thymidylate synthase (TS) inhibition. 1256 92
5-Fluoro-2'-deoxyuridine (FUdR) inhibits
thymidylate synthase
(TS). The inhibition of TS causes an imbalance of intracellular deoxyribonucleoside triphosphate (dNTP) pools which subsequently induced cell death. We investigated the molecular mechanisms of cell death after treated with FUdR in F28-7 strain (which induced necrosis) and F28-7-A strain (mutant of F28-7 strain which induced apoptosis). After treated with FUdR, we observed different size of DNA fragmentations. F28-7 strain induced DNA cleavaged into 100-200 kbp fragments and F28-7-A strain induced DNA cleavaged into oligonucleosomal sized fragments. In F28-7 strain, FUdR induced the increased mRNA level of c-jun, c-fos and c-myc genes,
caspase-3
like protease activity and the changes of mitochondrial membrane potential which were greater and earlier than those of F28-7-A strain. On the other hand, F28-7-A strain induced release of cytochrome c from mitochondrial, but not F28-7 strain. Furthermore, caspase-5 inhibitor was strongly inhibited the cell death of F28-7 strain. We suggest that it is concerned with intensity of intracellular signals in the cell death of F28-7 strain and F28-7-A strain.
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PMID:Mechanisms of cell death induced by 5-fluoro-2'-deoxyuridine (FUdR)--necrosis or apoptosis after treated with FUdR. 1290 97
The
thymidylate synthase
inhibitor 5-fluorouracil (5-FU) is used widely for chemotherapy of colorectal carcinoma. Recent studies showed that 5-FU affects polyamine metabolism in colon carcinoma cells. We therefore examined whether combinations of 5-FU with drugs that specifically target polyamine metabolism, i.e. N1,N11-diethylnorspermine (DENSPM) or alpha-difluoromethylornithine (DFMO), have synergistic effects in killing HCT116 colon carcinoma cells with wild-type or absent p53. Our results showed that simultaneous 5-FU and DENSPM, a spermine analogue, synergistically increased transcript levels of the polyamine catabolism enzyme spermidine/spermine N1-acetyltransferase, depleted spermine and spermidine, increased acetylated spermidine, and produced synergistic tumor cell apoptosis in both p53 wild-type and p53-null variants. By contrast, simultaneous combination of 5-FU with DFMO, an inhibitor of the polyamine biosynthetic enzyme ornithine decarboxylase, depleted putrescine but did not produce synergistic cell killing. Some pre-treatment and post-treatment regimens of DENSPM and DFMO were antagonistic to 5-FU depending on cellular p53 status. Protein and transcriptome expression analysis showed that combined 5-FU and DENSPM treatment activated caspase 9, but not
caspase 3
, and significantly suppressed NADH dehydrogenases and cytochrome c oxidases, consistent with the observed increase in hydrogen peroxide, loss of mitochondrial membrane potential, and release of cytochrome c. Our findings demonstrate the importance of the polyamine pathway in 5-FU effects and suggest that the combination of 5-FU with DENSPM has potential for development as therapy for colorectal carcinoma.
...
PMID:Combination of 5-fluorouracil and N1,N11-diethylnorspermine markedly activates spermidine/spermine N1-acetyltransferase expression, depletes polyamines, and synergistically induces apoptosis in colon carcinoma cells. 1554 79
The folate analogue BGC9331 is a new
thymidylate synthase
(TS) inhibitor showing a broad spectrum of cyto-toxic activity against several human solid tumors, including colorectal cancer. In this study, we investigated the anticancer activity of BGC9331 either alone or combined with 5-fluorouracil (5-FU), MTA (multi-target antifolate), oxali-platin and SN-38, the active metabolite of the topoisomerase I inhibitor CPT-11. The antiproliferative activity of each drug and BGC9331-based combinations was investigated in the HT-29 human colorectal cancer cell line and its HT-29/5-FU counterparts selected for resistance to 5-FU. BGC9331 combined with MTA or SN-38 induced synergistic responses in HT-29 cells. Treatment of HT-29 cells with either BGC9331 or SN-38 increased
caspase-3
activity and the percentage of apoptotic cells from 3 to 13%. Both drugs also augmented the proteolytic cleavage of the Rho-kinase ROCK-1 that was attenuated by the
caspase-3
pathway inhibitor z-DEVD-fmk. BGC9331 combined with SN-38 further increased the percentage of apoptotic cells to 25%, and inhibited cell cycle progression and cell proliferation by 65%. This was accompanied by proteolytic activation of ROCK-1, through both
caspase-3
-dependent and -independent mechanisms, as shown in
caspase-3
-deficient MCF-7 breast cancer cells. These encouraging results warrant further preclinical investigations and clinical trials on the use of BGC9331 combined with SN-38/CPT-11 in treatment of patients with advanced colorectal or gastric cancers.
...
PMID:Increased anticancer activity of the thymidylate synthase inhibitor BGC9331 combined with the topoisomerase I inhibitor SN-38 in human colorectal and breast cancer cells: induction of apoptosis and ROCK cleavage through caspase-3-dependent and -independent mechanisms. 1601 Apr 39
The 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, also called statins, are commonly used as lipid-lowering drugs that inhibit cholesterol biosynthesis. An anticancer effect, as a pleiotropic function of certain statins, has been hypothesized. In the present study, we investigated the effect of simvastatin, one of the natural statins, on cell proliferation, cell cycle, invasive activity, and molecular expressions associated with cell-extracellular matrix adhesion, signal transduction, and DNA synthesis in Tu167 and JMAR cells from head and neck squamous cell carcinoma. The addition of simvastatin resulted in a dose-dependent inhibition of cell growth and migration into the extracellular matrix. Considerable morphological changes occurred after treatment with simvastatin, demonstrating loss of cell adhesion and disruption of actin filaments in cytoplasm. The inhibitory effect of simvastatin on cell proliferation seemed to be associated with cell cycle arrest and increased expression of p21, p27, and activated
caspase-3
. The expression of beta1-integrin, a counter adhesion for the extracellular matrix, phosphorylated FAK, and phosphorylated ERK was decreased by treatment with simvastatin. The proapoptotic effect of simvastatin was inhibited by treatment with mevalonate. cDNA microarray assay demonstrated that molecular changes resulting from treatment with simvastatin included the up-regulation of cell cycle regulators and apoptosis-inducing factors and the down-regulation of integrin-associated molecules and cell proliferation markers. Of down-regulated genes induced by simvastatin treatment, a significant depletion of
thymidylate synthase
was confirmed using western blot analysis. These results imply that simvastatin has the potential to be effective for the prevention of the growth and metastasis of cancer cells.
...
PMID:Simvastatin inactivates beta1-integrin and extracellular signal-related kinase signaling and inhibits cell proliferation in head and neck squamous cell carcinoma cells. 1742 61
Inhibition of the repair of 5-fluorouracil (FU)-induced DNA lesions may improve the response of many tumors to this anticancer agent. Despite the identified associations between DNA strand breaks and the lethality of
thymidylate synthase
inhibitors, the role of DNA double-strand break (DSB) repair pathways in a cellular response to 5-FU treatment has not been studied yet. Isogenic cell lines defective (irs1SF), wild type (AA8), or reconstituted (1SFK8) in the DSB repair protein XRCC3 were used to investigate the effect of defective DSB repair on the overall sensitivity of cells to 5-FU and to see how targeting DSB repair may affect other cellular responses to 5-FU. Treatment with 5-FU resulted in (i) similar induction of DSB in both cell lines as indicated by the formation of gamma-H2AX (a marker for DSB). The repair of these breaks was complete in AA8 but not in irs1SF cells. (ii) Concentration-dependent reduction in the survival of both cell lines. The AA8 cells were six times more sensitive to 5-FU than the irs1SF cells. (iii) An earlier and more prolonged G(1)/S phase arrest in AA8 compared with the irs1SF cells. (iv) Induction of apoptosis as indicated by sub-G(1) cells and
caspase-3
activity in AA8 but not in irs1SF cells. XRCC3 complementation of irs1SF cells restored the wild-type phenotype. This result shows that targeting DSB repair is not always associated with increased sensitivity to DNA damaging agents such as 5-FU because it may affect other cellular responses such as cell cycle regulation and induction of apoptosis.
...
PMID:Targeting DNA double-strand break repair: is it the right way for sensitizing cells to 5-fluorouracil? 2007 15
Metastatic melanoma is an aggressive cancer with very low response rate against conventional chemotherapeutic agents such as dacarbazine (DTIC). Inhibitor of Rb-Raf-1 interaction RRD-251 was tested against the melanoma cell lines SK-MEL-28, SK-MEL-5, and SK-MEL-2. RRD-251 was found to be a potent inhibitor of melanoma cell proliferation, irrespective of V600E B-Raf mutation status of the cell lines. In a SK-MEL-28 xenograft experiment, RRD-251 exerted a significant suppression of tumor growth compared with vehicle (P = 0.003). Similar to in vitro effects, tumors from RRD-251-treated animals showed decreased Rb-Raf-1 interaction in vivo. Growth suppressive effects of RRD-251 were associated with induction of apoptosis as well as a G(1) arrest, with an accompanying decrease in S-phase cells. RRD-251 inhibited Rb phosphorylation and downregulated E2F1 protein levels in these cells. Real-time PCR analysis showed that RRD-251 caused downregulation of cell-cycle regulatory genes
thymidylate synthase
(TS) and cdc6 as well as the antiapoptotic gene Mcl-1. Combinatorial treatment of RRD-251 and DTIC resulted in a significantly higher apoptosis in DTIC resistant cell lines SK-MEL-28 and SK-MEL-5, as revealed by increased
caspase-3
activity and PARP cleavage. Because aberrant Rb/E2F pathway is associated with melanoma progression and resistance to apoptosis, these results suggest that the Rb-Raf-1 inhibitor could be an effective agent for melanoma treatment, either alone or in combination with DTIC.
...
PMID:Rb-Raf-1 interaction disruptor RRD-251 induces apoptosis in metastatic melanoma cells and synergizes with dacarbazine. 2113 44
Melanoma is one of the most common cancers, and its incidence has continued to increase over the past few decades. Chemotherapy resistance and related defects in apoptotic signaling are critical for the high mortality of melanoma. Effective drugs are lacking because apoptosis regulation in this tumor type is not well understood. The folate pathway has been considered an interesting target for anticancer therapies, and approaches targeting this pathway have recently been extended to melanoma treatment. In this study, the intracellular apoptosis signaling pathways of two melanoma cells lines (SK-MEL-2 and SK-MEL-28) were investigated after treatment with a new experimental antifolate substance (MR36) that targets
thymidylate synthase
. In both melanoma cell lines, apoptosis induction was triggered by a p53-independent mechanism. MR36-induced apoptosis was associated with a loss of both mitochondrial membrane potential and
caspase-3
activation. Induction of cell cycle arrest by MR36 was associated with changes in the expression of key cell cycle regulators, such as p21 and cyclin D1, and the hypophosphorylation of pRb. In addition, Fas signaling was also analyzed. These findings suggest that, unlike classical antifolates, MR36 exerted an inhibitory effect on both the enzymatic function and expression of
thymidylate synthase
, thereby inducing apoptosis through the activation of the extrinsic and intrinsic pathways in the melanoma cell lines. MR36 showed a different mechanism of action from the known antifolates (Nolatrexed and Pemetrexed) that resulted in higher anticancer activity. Therefore, MR36 should be included as a potential new therapeutic treatment in melanoma research.
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PMID:Biological evaluation of MR36, a novel non-polyglutamatable thymidylate synthase inhibitor that blocks cell cycle progression in melanoma cell lines. 2188 17
The aim of the present study was to investigate the role of NK4, an antagonist for hepatocyte growth factor (HGF) and the Met receptor, in regulating the response of cholangiocarcinoma (CCA) cells to 5-fluorouracil (5-FU). We established the CCA cell line, HuCC-T1, to produce abundant NK4 (Hu-NK4). Cell proliferation, cell cycle distribution, apoptosis, 5-FU metabolism and intracellular signaling were examined. There were no significant differences in the mRNA levels of
thymidylate synthase
, thymidine phosphorylase and dihydropyrimidine dehydrogenase between the mock-transfected control Hu-Em cells and Hu-NK4 cells, suggesting that NK4 expression does not alter 5-FU metabolism. Moreover, cell cycle analysis showed that 5-FU treatment caused a decrease in the proportion of cells in the G2/M phase while NK4 gene expression had little effect on the cell cycle distribution. However, 5-FU-induced apoptosis was significantly increased in the Hu-NK4 cells when compared to that in the Hu-Em cells. Further investigation revealed that NK4 gene expression enhanced 5-FU-induced
caspase-3
and caspase-9 activation, and that the apoptosis of cells was associated with modulation of expression of the Bcl-2 family members. Furthermore, western blot analysis revealed that both NK4 and 5-FU were inhibitors for HGF-induced phosphorylation of Met, but they may be independent factors. Collectively, these results suggest that following 5-FU treatment in CCA cell lines, NK4 was involved in apoptosis induction through the intrinsic mitochondrial pathway. This indicates that NK4 may be an important mediator of 5-FU-induced cell death. Moreover, downregulation of NK4 in response to 5-FU may represent an intrinsic mechanism of resistance to this anticancer drug.
...
PMID:NK4 regulates 5-fluorouracil sensitivity in cholangiocarcinoma cells by modulating the intrinsic apoptosis pathway. 2361 66
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