Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Current treatments for childhood brain tumor medulloblastoma (MB), radiation and chemotherapy, lead to undesirable side effects. Identification of antitumor agents that reduce the toxicity will thus have significant therapeutic value. In this study, we investigated all-trans-retinoic acid (ATRA) as an antitumor agent. Although high concentrations (1-10 microM) of retinoic acid derivatives are generally needed for significant antitumor effects in many cancer cells, we observed that pharmacologically relevant concentrations of ATRA were effective in inducing cell death in human MB cells. Using 10-fold lower concentrations (100-500 nM), we found that ATRA inhibits MB (DAOY, D283, D425, and D458) cell proliferation as determined by cell viability [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and bromodeoxyuridine incorporation assays. Furthermore, 100 nM ATRA was potent in inhibiting the anchorage-independent growth of the sensitive cell lines (D283, D425, and D458) in soft agar assays. We also demonstrate that the ATRA-induced decrease in cell viability was due to increased cell death by apoptosis, which was accompanied by a 20-fold induction of caspase-3 activity in the most sensitive cell line, D458. By contrast, induction of caspase-3 was only 2-fold in the relatively insensitive DAOY cells. Furthermore, ATRA-induced cell death in D283, D425, and D458 cells was accompanied by activation of caspase-3, a key executioner of apoptosis. We also demonstrate that activated caspase-3 resulted in cleavage of 116-kDa poly(ADP-ribose) polymerase 1 to its signature fragments (85 and 29 kDa). Pretreatment with a specific caspase-3 inhibitor, DEVD-CHO, significantly reduced ATRA-induced apoptotic cell death. Thus, we demonstrate for the first time that low concentrations of ATRA inhibit MB cell proliferation and induce apoptotic cell death in part by activating caspase-3/poly(ADP-ribose) polymerase 1 effector pathway, and we show that retinoic acids and novel retinoids are potential antitumor agents in MB therapy.
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PMID:All-trans-retinoic acid-induced apoptosis in human medulloblastoma: activation of caspase-3/poly(ADP-ribose) polymerase 1 pathway. 1451 26

N-(4-hydroxyphenyl) retinamide (4-HPR, fenretinide) a synthetic retinoid is in clinical trials for the treatment of several malignancies. However, its biological effects and therapeutic value in childhood brain tumor medulloblastoma (MB) has not been investigated. In this study, we report for the first time that fenretinide (2.5-10 microM) induces apoptotic cell death in human MB cells. We observed significant inhibition of cell survival in four MB cell lines (D425MED, D458MED, D283MED and D341MED) as determined by MTT assays. These results were further supported by inhibition of anchorage-independent colony formation in soft agar. Fenretinide-induced decrease in cell viability was in part due to activation of caspase-3 dependent cell death, which was further supported by the cleavage of poly(ADP-ribose) polymerase-1 (PARP-1), a caspase-3 substrate. Cell death was partially prevented by the antioxidant, l-ascorbic acid suggesting that free radical intermediates might be involved in fenretinide effects. These results suggest that pharmacologically achievable concentrations of fenretinide are effective in killing MB cells and thus show its therapeutic potential to treat human MB.
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PMID:Anticancer effects of fenretinide in human medulloblastoma. 1639 27

Ependymomas are the third most common pediatric brain tumor with an overall survival of approximately 50%. Recently, we showed that telomerase [human telomerase reverse transcriptase (hTERT)] expression is a predictor of poor outcome in pediatric ependymoma. Thus, we hypothesized that ependymomas with functional telomerase may behave more aggressively and that these patients may benefit from anti-telomerase therapy. To address our hypothesis, we investigated the effect of telomerase inhibition on primary ependymoma cells harvested at the time of surgery, as no animal models or established cell lines are readily available for this tumor. The cells were characterized for glial fibrillary acidic protein (GFAP) and hTERT expression, initial telomere length and telomerase activity. They were then subjected to telomerase inhibition (MST-312, 1 microM) and tested for effects on cell viability (MTT assay), proliferation (MIB-1), apoptosis (cleaved caspase 3) and DNA damage (gammaH2AX). After 72 h of telomerase inhibition, primary ependymoma cells showed a significant decrease in cell number (P < 0.001), accompanied by increased DNA damage (gammaH2AX expression) (P < 0.01) and decreased proliferative index (MIB-1) (P < 0.01). Half showed an increase in apoptosis (cleaved caspase 3). These data suggest that telomerase inhibition may be an effective adjuvant therapy in pediatric ependymoma, potentially inducing tumor growth arrest in the short term, independent of telomere shortening.
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PMID:Telomerase inhibition as a novel therapy for pediatric ependymoma. 2018 88

Medulloblastoma (MB) is the most common type of malignant childhood brain tumor. We previously showed that inhibitors of apoptosis proteins (IAP) small-molecule inhibitors (LCL161 or LBW242) combined with chemotherapy have synergistic antiproliferative effects on MB cells. The synergistic antitumor effects of combination treatments happen through induction of autophagy and caspase-3/7-activated apoptosis. Here, we investigated the effects of IAP inhibitors or silencing IAP on cell cycle regulation. We discovered that treatment with IAP inhibitors or their combination with conventional chemotherapy (vincristine or cisplatin), as well as RNAi knockdown of cIAP1/2 or XIAP arrested MB cells in the G2/M phase through downregulation of cyclin B1-CDK1 and cyclin A-CDK1/2. Among these three IAPs, only silencing cIAP1 expression enhanced p21 dependent-G2/M phase accumulation. IAP inhibitors reduced cIAP1 expression and increased p21 expression in time course experiments. Furthermore, cIAP1 can govern p21 proteasomal degradation via neddylation in lieu of ubiquitination. Inhibition of IAPs significantly abrogated cIAP1-mediated p21 degradation. We also observed an inverse correlation between nuclear cIAP1 and nuclear p21 expressions in MB tumor tissues. These findings provide new mechanistic evidence of the influence of IAP inhibitors on MB cell proliferation through disruption of the cell cycle.
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PMID:Targeting inhibitors of apoptosis proteins suppresses medulloblastoma cell proliferation via G2/M phase arrest and attenuated neddylation of p21. 2998 17

Medulloblastoma is a common pediatric brain tumor and one of the main types of solid cancers in children below the age of 10. Recently, cholesterol-lowering "statin" drugs have been highlighted for their possible anti-cancer effects. Clinically, statins are reported to have promising potential for consideration as an adjuvant therapy in different types of cancers. However, the anti-cancer effects of statins in medulloblastoma brain tumor cells are not currently well-defined. Here, we investigated the cell death mechanisms by which simvastatin mediates its effects on different human medulloblastoma cell lines. Simvastatin is a lipophilic drug that inhibits HMG-CoA reductase and has pleotropic effects. Inhibition of HMG-CoA reductase prevents the formation of essential downstream intermediates in the mevalonate cascade, such as farnesyl pyrophosphate (FPP) and gernaylgerany parophosphate (GGPP). These intermediates are involved in the activation pathway of small Rho GTPase proteins in different cell types. We observed that simvastatin significantly induces dose-dependent apoptosis in three different medulloblastoma brain tumor cell lines (Daoy, D283, and D341 cells). Our investigation shows that simvastatin-induced cell death is regulated via prenylation intermediates of the cholesterol metabolism pathway. Our results indicate that the induction of different caspases (caspase 3, 7, 8, and 9) depends on the nature of the medulloblastoma cell line. Western blot analysis shows that simvastatin leads to changes in the expression of regulator proteins involved in apoptosis, such as Bax, Bcl-2, and Bcl-xl. Taken together, our data suggests the potential application of a novel non-classical adjuvant therapy for medulloblastoma, through the regulation of protein prenylation intermediates that occurs via inhibition of the mevalonate pathway.
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PMID:Simvastatin Induces Apoptosis in Medulloblastoma Brain Tumor Cells via Mevalonate Cascade Prenylation Substrates. 3131 83