Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cisplatin is a DNA-damaging chemotherapeutic drug that may have a role in the adjuvant chemotherapy of several solid tumors, such as malignant glioblastoma, and the status of p53 tumor suppressor protein is a critical determinant of cisplatin chemosensitivity. In the present study, we showed the relationship of p53 status and chemosensitivity of cisplatin between two human malignant glioblastoma cell lines, A172 and T98G, harboring wild-type and mutant-type p53, respectively. Cisplatin was found to be more cytotoxic to A172 than T98G cells in a time- and concentration-dependent manner. Cisplatin-induced cytotoxicity manifested as apoptosis, characterized by genomic DNA fragmentation, nuclear condensation and an increase in sub-G1 population. Cisplatin induced the accumulation of p53 and p21 proteins in A172 cells, but not in T98G cells. The introduction of the adenovirus-mediated wild-type p53 gene into T98G cells resulted in the decrease of viability as well as the increase in sub-G1 population with p53 accumulation, activation of caspase-3 protease and release of cytochrome c from the mitochondria. These data strongly suggest that the expression of p53 is essential for the cytotoxic effect of cisplatin in human malignant glioblastoma cells, A172 and T98G, and the introduction of apoptotic signal molecules, such as p53, will be beneficial to achieve chemosensitivity in malignant glioma.
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PMID:Induction of p53-mediated apoptosis and recovery of chemosensitivity through p53 transduction in human glioblastoma cells by cisplatin. 1632 87

The present study examined the possibility to enhance lung cancer cell cytotoxicity and apoptosis of the anticancer drug cisplatin by exposure with adenylate cyclase (AC) toxin from Bordetella pertussis. A malignant mesothelioma cell line (P31) and a small-cell lung cancer cell line (U1690) were exposed to increasing concentrations of cisplatin and AC toxin, alone or in combination. Cytotoxicity was determined by a fluorescein-based assay and apoptosis by flow cytometry quantification of annexin V binding. Caspase-3, -8, and -9 activities were measured by enzyme activity assays. The cytotoxicity of AC toxin was time and dose dependent with an LD50 value at 72 h of 3 and 7 mg/L for P31 cells and U1690 cells, respectively. Cisplatin showed a similar time- and dose-dependent cytotoxicity, which was increased in the presence of a low toxic concentration (1 mg/L) of AC toxin. Furthermore, cisplatin caused a dose-dependent increase of annexin V binding cells of both cell lines after 24-h incubation, which was also enhanced in combination with AC toxin. AC toxin (1 mg/L) increased cisplatin-induced caspase-3, -8, and -9 activities in U1690 cells. Only minor increases of caspase-8 and -9 were noted for P31 cells. The present results, together with the knowledge that bacterial toxins decrease side effects of traditional cancer treatment, suggest a possibility to use them to enhance the therapeutic effect of cancer chemotherapy with reduced clinical adverse effects.
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PMID:Adenylate cyclase toxin from Bordetella pertussis enhances cisplatin-induced apoptosis to lung cancer cells in vitro. 1655 48

Cisplatin induces renal cell injury and death, resulting in nephrotoxicity that limits its use in cancer therapy. Using cell culture models, recent work has suggested the involvement of p53 in renal cell apoptosis during cisplatin treatment. However, the signals upstream of p53 remain elusive. ATM and ATR are critical regulators of p53 under various conditions of DNA damage. Here, we show that ATM, and not ATR, was proteolytically cleaved into specific fragments of approximately 210 and 150 kDa during cisplatin-induced tubular cell apoptosis. ATM cleavage was paralleled by the development of apoptosis. VAD, a broad-spectrum inhibitor of caspases, attenuated the cleavage of ATM, whereas the inhibitors of specific caspases were less effective. In caspase-3-deficient MCF-7 cells, ATM was cleaved, releasing the 210- but not the 150-kDa fragment. Recombinant caspase-3 was much more effective than caspase-7 in cleaving ATM that was immunoprecipitated from cell lysates. During cisplatin incubation, VAD protected ATM and enhanced p53 phosphorylation. In vitro assay of protein kinase activity further showed that ATM immunoprecipitated from cisplatin-treated cells had significantly lower kinase activity toward p53 than that from control cells. Importantly, the protein kinase activity was restored in ATM that was protected by VAD during cisplatin incubation. ATM deficiency sensitized the cells to cisplatin-induced apoptosis, suggesting a cytoprotective role of ATM in this experimental model. Thus proteolysis of ATM by caspases may inactivate this regulatory molecule to facilitate the progression of apoptosis.
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PMID:Caspase-mediated cleavage of ATM during cisplatin-induced tubular cell apoptosis: inactivation of its kinase activity toward p53. 1684 90

One of the mechanisms of cisplatin cell cytotoxicity is the mitochondria-associated induction of apoptosis. The morphological or functional change of mitochondria in cisplatin-resistant cells has already been reported. Herein we present additional data describing the mitochondrial genomic and functional changes in cisplatin- resistant cells. Cisplatin increased the level of apoptotic cells in cisplatin-sensitive human ovarian carcinoma OV 2008 and C13 cells by 3.90+/-1.01 (SD; N=3) (p<0.01)-fold and 2.03+/-0.20 (SD; N=3) (p<0.01)-fold compared to the basal apoptotic level. This indicates a lower level induction of apoptosis by 50% in cisplatin-resistant OV 2008/C13 *5.25 variant (C13) cells. In both cell types, cisplatin cytotoxicity is mostly inhibited by the caspase-9 inhibitor as well as the caspase-3 inhibitor, Ac-DEVD-CHO, suggesting that the mitochondrial downstream event was functioning well in both the C13 cells and in OV 2008 cells. Mitochondrial transmembrane potential (DeltaPsim) determined by flow cytometry using DiOC6-stained cells revealed a significant depolarization of C13 cells as compared to OV 2008 cells. Treatment of these cells with cisplatin or hydrogen peroxide induces complete mitochondrial DNA damage in OV 2008 cells, while only partial DNA-destruction is observed in C13 cells, strongly suggesting that mitochondria are resistant to cisplatin and oxidative stress response. Continuous oxygen consumption of these cells monitored by a multi-channel dissolved oxygen meter is 1.70-fold higher in OV 2008 cells than C13 cells and the oxygen consumption was decreased by 30% in C13 cells, suggesting mitochondrial respiratory malfunction in these cells. The hypothesis generated here is that mitochondrial DNA resistance to cisplatin and oxidative stress response might be one of the main characteristics concerning the lower level of apoptosis induced by cisplatin. However, the mechanism by which the mitochondrial DNA encoded molecule is involved in cisplatin resistance remains to be determined.
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PMID:Characterization of mitochondria in cisplatin-resistant human ovarian carcinoma cells. 1701 83

Cisplatin [cis-diamminedichloroplatinum (II)]-treated murine peritoneal macrophages interact with L929 cells in vitro in a sequential manner, resulting in the formation of contact between the two cells. This interaction leads to the death of L929 cells by the process of apoptosis. The detailed investigations have suggested the involvement of two different pathways in macrophage-mediated L929 cell apoptosis. It is observed that the induction of apoptosis in L929 cells by cisplatin-treated macrophages is contact dependent and is mediated through Fas-Fas ligand and tumor necrosis factor-tumor necrosis factor receptor 1 pathways. This conclusion was based on the Western blot and immunoprecipitation analysis of Fas-Fas ligand, tumor necrosis factor-tumor necrosis factor receptor 1, Fas-associated death domain and tumor necrosis factor receptor-associated death domain. The Fas-Fas ligand interaction between macrophages and L929 cells increased the expression of Fas-associated death domain, and tumor necrosis factor-tumor necrosis factor receptor 1 interaction between macrophages and L929 cells increased the expression of tumor necrosis factor receptor-associated death domain in L929 cells. The induction of apoptosis in L929 cells was investigated by DNA fragmentation, Annexin V staining and Western blot analysis of Bax, Bcl-2, Bid, cytochrome c, poly(ADP ribose) polymerase, CAD, caspase-8 and caspase-3.
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PMID:Cisplatin-treated murine peritoneal macrophages induce apoptosis in L929 cells: role of Fas-Fas ligand and tumor necrosis factor-tumor necrosis factor receptor 1. 1715 5

Although expressing adequate levels of functional tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors DR4/DR5, significant proportion of cancer cells exhibit resistance to the cytotoxic effect of this ligand. Exposure of Apo2L/TRAIL-refractory cancer cells to cytotoxic chemotherapeutic agents enhances their sensitivity to Apo2L/TRAIL cytotoxicity. This study aims to elucidate the molecular mechanism responsible for the cisplatin-mediated enhancement of Apo2L/TRAIL sensitivity in cultured esophageal cancer cells. Exposure of cancer cells to sublethal concentrations of cisplatin resulted in profound potentiation of their susceptibility to Apo2L/TRAIL cytotoxicity as indicated by 2- to >20-fold reduction in Apo2L/TRAIL IC50 values. Significant activation of caspase-8, caspase-9, and caspase-3 was observed only in cells treated with cisplatin/Apo2L/TRAIL combination and not in those exposed to either agent alone. More importantly, activation of these key caspases was significantly abrogated by overexpression of Bcl2 or by the selective caspase-9 inhibitor. This observation strongly suggested that caspase-8 activation in cells treated with the cisplatin/Apo2L/TRAIL combination was secondary to the mitochondria-mediated amplification feedback loop and activation of the executioner caspase-3 was dependent on the recruitment of the intrinsic pathway characteristic of the type II cell. Profound combination-mediated cytotoxicity and induction of apoptosis was completely suppressed either by Bcl2 overexpression or by inhibition of caspase-9 activity, which conclusively pointed to the essential role of the mitochondria-dependent death signaling cascade in this process. Cisplatin sensitizes esophageal cancer cells to Apo2L/TRAIL cytotoxicity by potentiation of the mitochondria-dependent death signaling pathway that leads to amplification of caspase activation, particularly caspase-8, by the feedback loop to efficiently induce apoptosis.
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PMID:Enhancement of Apo2L/TRAIL-mediated cytotoxicity in esophageal cancer cells by cisplatin. 1717 3

Cisplatin is a highly effective chemotherapeutic agent but with significant ototoxic side effects. Apoptosis is an important mechanism of cochlear hair cell loss following exposure to an ototoxic level of cisplatin. The present study investigated the effects of the cannabinoid receptor 2 (CB2) ligand JWH-015 on cisplatin-induced apoptosis. CB2 mRNA was constitutively expressed in the auditory cell line HEI-OC1. By using MTT assay, DNA fragmentation, and FACS analysis, we demonstrated that apoptosis induced by cisplatin was inhibited by treatment with JWH-015 in a dose-dependent manner. Activation of caspase-3, caspase-8, and caspase-9 was detected after treatment with cisplatin, and the cleavage of poly-(ADP)-ribose polymerase (PARP) was observed within cisplatin-treated HEI-OC1 cells. JWH-015 inhibited the activation of caspase-3, caspase-8, and caspase-9; cleavage of PARP; and release of cytochrome c. JWH-015 also inhibited the apoptosis through activation of the extracellular signal-regulated kinase pathway. Finally, JWH-015 inhibited cisplatin-induced reactive oxygen species and tumor necrosis factor-alpha production. Collectively, these findings show that blocking a critical step in apoptosis by using JWH-015 may be a useful strategy to prevent harmful side effects of cisplatin ototoxicity in patients having to undergo chemotherapy.
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PMID:Antiapoptotic mechanism of cannabinoid receptor 2 agonist on cisplatin-induced apoptosis in the HEI-OC1 auditory cell line. 1718 90

[[trans-PtCl(NH(3))(2)](2)mu-(trans-Pt(NH(3))(2)(H(2)N(CH(2))(6)-NH(2))(2))](4+) (BBR3464) is a cationic trinuclear platinum drug that is being evaluated in phase II clinical trials for treatment of lung and ovarian cancers. The structure and DNA binding profile of BBR3464 is different from drugs commonly used clinically. It is of great interest to evaluate the difference between the mechanisms of uptake employed by BBR3464 and cisplatin (c-DDP), as altered uptake may explain chemoresistance. Using transfected cell lines, we show that both c-DDP and BBR3464 use the copper transporter hCTR1 to enter cells and to a lesser extent, the ATP7B transporter to exit cells. Copper influenced c-DDP and BBR3464 uptake similarly; it increased the c-DDP and BBR3464 uptake in ovarian (A2780) and colorectal (HCT116) carcinoma cell lines as detected by ICP-OES. However, the effects of copper on c-DDP- and BBR3464-mediated cytotoxicity differed. Copper decreased c-DDP-induced apoptosis, caspase-3/7 activation, p53 induction and PARP cleavage in cancer cell lines. In contrast, copper increased BBR3464-induced apoptosis, and had little effect on caspase activation, PARP cleavage, and p53 induction. It was concluded that BBR3464 employs mechanisms of intracellular action distinct from c-DDP. Although these drugs use the same cellular transporters (hCTR1 and ATP7B) for influx and efflux, downstream effects are different for the two drugs. These experiments illustrate fundamental differences in the mechanisms of action between cisplatin and the novel Pt-based drug BBR3464.
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PMID:Differences in the cellular response and signaling pathways of cisplatin and BBR3464 ([[trans-PtCl(NH3)(2)]2mu-(trans-Pt(NH3)(2)(H2N(CH2)(6)-NH2)2)]4+) influenced by copper homeostasis. 1723 60

Mcl-1 is an antiapoptotic member of the Bcl-2 family that plays an important role in cell survival. We demonstrate that proteasome-dependent regulation of Mcl-1 plays a critical role in renal tubular epithelial cell injury from cisplatin. Protein levels of Mcl-1 rapidly declined in a time-dependent manner following cisplatin treatment of LLC-PK(1) cells. However, mRNA levels of Mcl-1 were not altered following cisplatin treatment. Expression of other antiapoptotic members of the Bcl-2 family such as Bcl-2 and BclxL was not affected by cisplatin treatment. Cisplatin-induced loss of Mcl-1 occurs at the same time as the mitochondrial release of cytochrome c, activation of caspase-3, and initiation of apoptosis. Treatment of cells with cycloheximide, a protein synthesis inhibitor, revealed rapid turnover of Mcl-1. In addition, treatment with cycloheximide in the presence or absence of cisplatin demonstrated that cisplatin-induced loss of Mcl-1 results from posttranslational degradation rather than transcriptional inhibition. Overexpression of Mcl-1 protected cells from cisplatin-induced caspase-3 activation and apoptosis. Preincubating cells with the proteasome inhibitor MG-132 or lactacystin not only restored cisplatin-induced loss of Mcl-1 but also resulted in an accumulation of Mcl-1 that exceeded basal levels; however, Bcl-2 and BclxL levels did not change in response to MG-132 or lactacystin. The proteasome inhibitors effectively blocked cisplatin-induced mitochondrial release of cytochrome c, caspase-3 activation, and apoptosis. These studies suggest that proteasome regulation of Mcl-1 is crucial in the cisplatin-induced apoptosis via the mitochondrial apoptotic pathway and that Mcl-1 is an important therapeutic target in cisplatin injury to renal tubular epithelial cells.
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PMID:Mcl-1 is downregulated in cisplatin-induced apoptosis, and proteasome inhibitors restore Mcl-1 and promote survival in renal tubular epithelial cells. 1731 6

Two different hepatoma cell lines were incubated for 48h with chemotherapeutic drugs cisplatin, paclitaxel and 5-FU to determine their ability to induce cytotoxicity and DNA fragmentation as well as to modify the expression of some cell death-related genes that could be involved in the resistance to therapy. We observed that cisplatin and paclitaxel induced cytotoxicity, but significant differences between both cell lines, were found only in the case of paclitaxel. At 48h, apoptosis was clearly present in Hep3B cells treated with cisplatin and HepG2 cells treated with paclitaxel. 5-FU induced cytotoxicity in both cell lines but only at higher concentrations than the other two drugs, triggering apoptosis and necrosis in HepG2 cells and only necrosis in Hep3B. When a time course was performed for the first 8h of treatment to elucidate the initial mechanism of cell death responsible for DNA fragmentation, we observed that 5-FU in Hep3B, and cisplatin in both cell lines, induces primary necrosis, whereas at the concentration tested here, paclitaxel clearly triggers apoptosis in both cell lines. HepG2 cells were weakly sensitive to 5-FU in the first 8h of treatment, so the primary mechanism of cell death was not clear, but results seem to indicate that it could be apoptosis. At 48h, Bax was not up-regulated with any of the treatments, whereas cisplatin was able to induce Bcl-xL down-regulation in both cell lines. Treatment with 5-FU also down-regulated Bcl-xL in HepG2 cells. We also measured variations in the expression of survivin, an inhibitor of apoptosis that has also been involved in mitototic catastrophe. Hep3B cells seem to show an increase in protein levels with all treatments. Exposure to paclitaxel resulted in the highest effect. In the case of HepG2 cells, there was a decrease in survivin expression when cells were treated with 5FU and paclitaxel, both treatments showing complete loss of the protein. Using an antibody that recognizes unprocessed caspase-3, we observed that the enzyme was assumingly activated in HepG2 cells treated with 5FU and paclitaxel, but only weakly after treatment with cisplatin. Hep3B cells did not show activation since the levels of the pro-enzyme remained the same as that in the control. In conclusion, the three drugs tested in this study could induce cell death, with paclitaxel being more effective inducing apoptosis. 5FU was only effective at high doses and its mechanism seems to be primarily related to necrosis in Hep3B and probably apoptosis in HepG2. Cisplatin mechanism of cell death is probably mediated by the decrease in anti-apoptotic protein Bcl-xL whereas paclitaxel and 5FU are decreasing the apoptosis inhibitor survivin. According to pro-enzyme levels, caspase-3 was only activated in HepG2 cells, whereas in the case of Hep3B cells the mechanisms of toxicity appear to be caspase-3-independent at the time and concentrations tested in this study. The resistance of Hep3B cells to death induced by chemotherapy could be related to an increase in the expression of IAP survivin, which can decrease cell response to the treatment or even switch the type of death from apoptosis to another kind, making therapy less efficient.
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PMID:Characterization of cell death events induced by anti-neoplastic drugs cisplatin, paclitaxel and 5-fluorouracil on human hepatoma cell lines: Possible mechanisms of cell resistance. 1739 42


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