Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.61 (caspase-8)
 6,833 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown cancer preventive activity in patients who took them frequently. These drugs can induce tumor cells to undergo apoptosis in vitro. NS398, a cyclooxygenase-2 (COX-2)-selective inhibitor, has been reported to cause apoptosis in cancer cell lines. Therefore, we examined its effect on 15 human colon cancer cell lines and investigated its mechanism of action. NS398 decreased cell viability in all of the cell lines. Tumor cells that expressed COX-2 were shown to be more sensitive to NS398 treatment. In three selected colon cancer cell lines, NS398-induced apoptosis was mediated by the release of cytochrome c from mitochondria and, consequently, by the activation of caspase-9 and caspase-3 and by the cleavage of poly(ADP-ribose) polymerase. In contrast, caspase-8 was not involved in NS398-induced apoptosis, which suggested that the cytochrome c pathway may play an important role in NS398-induced apoptosis in colon cancer cell lines. Therefore, the combination of NS398 with apoptosis-inducing drugs through cytochrome c-independent pathways may be warranted.
 ...
PMID:Induction of apoptosis in colon cancer cells by cyclooxygenase-2 inhibitor NS398 through a cytochrome c-dependent pathway. 1130 52

Pharmacologically safe compounds that can inhibit the proliferation of tumor cells have potential as anticancer agents. Curcumin, a diferuloylmethane, is a major active component of the food flavor turmeric (Curcuma longa) that has been shown to inhibit the proliferation of a wide variety of tumor cells. The apoptotic intermediates through which curcumin exhibits its cytotoxic effects against tumor cells are not known, and the participation of antiapoptotic proteins Bcl-2 or Bcl-xl in the curcumin-induced apoptosis pathway is not established. In the present report we investigated the effect of curcumin on the activation of the apoptotic pathway in human acute myelogenous leukemia HL-60 cells and in established stable cell lines expressing Bcl-2 and Bcl-xl. Curcumin inhibited the growth of HL-60 cells (neo) in a dose- and time-dependent manner, whereas Bcl-2 and Bcl-xl-transfected cells were relatively resistant. Curcumin activated caspase-8 and caspase-3 in HL-60 neo cells but not in Bcl-2 and Bcl-xl-transfected cells. Similarly, time-dependent poly(ADP)ribose polymerase (PARP) cleavage by curcumin was observed in neo cells but not in Bcl-2 and Bcl-xl-transfected cells. Curcumin treatment also induced BID cleavage and mitochondrial cytochrome c release in neo cells but not in Bcl-2 and Bcl-xl-transfected cells. In neo HL-60 cells, curcumin also downregulated the expression of cyclooxygenase-2. Because DN-FLICE blocked curcumin-induced apoptosis, caspase-8 must play a critical role. Overall, our results indicate that curcumin induces apoptosis through mitochondrial pathway involving caspase-8, BID cleavage, cytochrome c release, and caspase-3 activation. Our results also suggest that Bcl-2 and Bcl-xl are critical negative regulators of curcumin-induced apoptosis.
 ...
PMID:Curcumin (diferuloylmethane) induces apoptosis through activation of caspase-8, BID cleavage and cytochrome c release: its suppression by ectopic expression of Bcl-2 and Bcl-xl. 1175 35

The inducible cyclooxygenase-2 (COX-2) gene regulates prostaglandin biosynthesis,is up-regulated in colorectal cancers, and can influence apoptotic susceptibility. We determined whether forced COX-2 expression modulates apoptosis induction by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of tumor necrosis factor ligand family, and examined determinants of the apoptotic pathway, including membrane death receptors (DR-4 and DR-5). HCT-15 colon cancer cells lacking endogenous COX-2 proteins were stably transfected with the COX-2 cDNA and incubated with TRAIL. Forced COX-2 expression significantly attenuated TRAIL-induced apoptosis and was associated with transcriptional repression of DR-5 and up-regulation of Bcl-2. COX-2 transfectants showed reduced DR-5 mRNA and protein expression as well as reduced caspase-8, caspase-3, and caspase-9 activation relative to parental cells. Sulindac sulfide treatment restored DR-5 expression and, when combined with TRAIL, reduced cell viability to a greater extent than did either drug alone. In summary, modulation of DR-5 and Bcl-2 levels by COX-2 attenuates TRAIL-induced apoptosis and represents a novel mechanism of intrinsic drug resistance in human colon cancer cells.
 ...
PMID:Cyclooxygenase-2 overexpression inhibits death receptor 5 expression and confers resistance to tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in human colon cancer cells. 1220 39

The cyclooxygenase-2 (COX-2) gene encodes an inducible enzyme that converts arachidonic acid to prostaglandins and is up-regulated in colorectal neoplasms. Evidence indicates that COX-2 may regulate apoptosis and can influence the malignant phenotype. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX enzymes and induce apoptosis in colorectal cancer cell lines, which may contribute to their antitumor effects. To determine whether forced COX-2 expression modulates susceptibility to drug-induced apoptosis, HCT-15 colon carcinoma cells were stably transfected with the COX-2 cDNA, and two clones overexpressing COX-2 were isolated. Selective COX-2 (NS398) and nonselective (sulindac sulfide) COX inhibitors, as well as 5-fluorouracil (5-FU), induced apoptosis (terminal deoxynucleotidyl transferase-mediated nick end labeling in a dosage-dependent manner. Forced COX-2 expression significantly attenuated induction of apoptosis by all three of the drugs compared with parental HCT-15 cells. NSAIDs and 5-FU induced the mitochondrial release of cytochrome c as well as caspase-3 and -9 activation, and to a much lesser extent, caspase-8. COX-2-overexpressing cells showed reduced cytochrome c and caspase activation, relative to parental cells. A specific inhibitor of caspase-3 restored cell survival after drug treatment. COX-2 transfectants were found to overexpress the antiapoptotic Bcl-2 mRNA and protein relative to parental cells. In conclusion, forced COX-2 expression significantly attenuates apoptosis induction by NSAIDs and 5-FU through predominant inhibition of the cytochrome c-dependent apoptotic pathway. COX-2-mediated up-regulation of Bcl-2 suggests a potential mechanism for reduced apoptotic susceptibility.
 ...
PMID:Cyclooxygenase-2 overexpression reduces apoptotic susceptibility by inhibiting the cytochrome c-dependent apoptotic pathway in human colon cancer cells. 1241 64

By employing two electron microscopy techniques, postembedding double- and triple immunocytochemical gold-labelling combined with embedment-free electron microscopy (EF-EM), we have detected previously unreported nuclear and cytoplasmic complexes between different proapoptatic proteins in a human cancer cell line COLO 205 stimulated to apoptosis by nimesulide, a specific cyclooxygenase-2 inhibitor. Experiments with the use of double- and triple immunolabelling visualized the colocalization of proapoptotic proteins such as Bax with Bid, Bax with Bid and voltage-dependent anion channel protein (VDAC-1), and Bax with Bid and caspase-8, on organellar membranes and within the nucleus. Application of this technique in combination with EF-EM technique augments our knowledge on the precise identification and relationship of subcellular structures containing Bax, Bid, VDAC-1 and caspase-8.
 ...
PMID:A novel embedment-free immunoelectron microscopy technique reveals association of apoptosis-regulating proteins with subcellular structures. 1281 92

A complete cytokine mix (CCM) or its individual components tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) were used to switch resting murine astrocytes to reactive states. The transformation process was characterized by differential up-regulation of interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthetase (iNOS) mRNA and protein and a subsequent release of prostaglandin E2, nitric oxide (NO) and IL-6. Both CD95L and anti-CD95 antibodies triggered caspase activation followed by apoptotic death in fully pro-inflammatory astrocytes, whereas resting cells were totally resistant. Two other death-inducing ligands, TNF and TNF-related apoptosis-inducing ligand (TRAIL) did not induce apoptosis in reactive astrocytes. The switch in astrocyte sensitivity was accompanied by up-regulation of caspase-8 and CD95 as well as the capacity to recruit Fas-associated death domain (FADD) to the activated death receptor complex. Neither CD95-mediated death, nor other inflammatory parameters were affected by inhibition of iNOS or COX, respectively. Accordingly, IFN-gamma was absolutely essential for up-regulation of iNOS, but not for the switch in apoptosis sensitivity. In contrast, p38 kinase activity was identified as an important controller of both the inflammatory reaction and apoptosis both in astrocytes stimulated with CCM and in glia exposed to TNF and IL-1 only.
 ...
PMID:Defined inflammatory states in astrocyte cultures: correlation with susceptibility towards CD95-driven apoptosis. 1467 62

Malignant rhabdoid tumor (MRT) is a rare and highly aggressive tumor presenting in the kidney and soft tissue in childhood. However, effective treatment for MRT has not been established. We investigated the antitumor effect of etodolac, a selective cyclooxygenase-2 inhibitor, on MRT cells in vitro using the MRT cell line FRTK-1. Etodolac induced apoptosis of FRTK-1 cells through activation of caspase-8, -9 and -3. Moreover, several caspase inhibitors completely or partially inhibited etodolac-induced apoptosis. Our data indicated that etodolac had an antitumor effect on MRT cells and holds promise as a novel therapeutic strategy for MRT.
 ...
PMID:Etodolac, a selective cyclooxygenase-2 inhibitor, induces apoptosis by activating caspases in human malignant rhabdoid tumor cells (FRTK-1). 1714 95

The objective of this study was to determine the chemopreventive effects of sarcophine-diol (SD) on 7,12-dimethylbenz(a)anthracene initiated and 12-O-tetradecanoylphorbol-13-acetate promoted skin tumor development in mice and its possible mechanisms of action. SD pretreatment significantly (P<0.05) decreased skin papilloma development during promotion phase. SD significantly (P<0.05) increased caspase-3 and decreased cyclooxygenase-2 during initiation phase or promotion phase. SD significantly (P<0.05) increased caspase-8 during promotion phase. SD resulted in a 95% reduction in 12-O-tetradecanoylphorbol-13-acetate-induced DNA synthesis. SD could be an effective chemopreventive agent for skin cancer by enhancing apoptosis and decreasing cell proliferation.
 ...
PMID:Chemopreventive effects of sarcophine-diol on skin tumor development in CD-1 mice. 1732 Oct 42

Zyflamend, a polyherbal preparation, was designed based on constituents that exhibit antiproliferative, antiinflammatory, antioxidant, antiangiogenic, and apoptotic activities through a mechanism that is not well defined. Because the nuclear factor (NF)-kappaB has been shown to regulate proliferation, invasion, and metastasis of tumor cells, we postulated that Zyflamend modulates the activity of NF-kappa B. To test this hypothesis, we examined the effect of this preparation on NF-kappaB and NF-kappaB-regulated gene products. We found that Zyflamend inhibited receptor activator of NF-kappa B ligand-induced osteoclastogenesis, suppressed tumor necrosis factor (TNF)-induced invasion, and potentiated the cytotoxicity induced by TNF and chemotherapeutic agents, all of which are known to require NF-kappa B activation. Zyflamend suppressed NF-kappa B activation induced by both TNF and cigarette smoke condensate. The expression of NF-kappa B-regulated gene products involved in antiapoptosis (inhibitor-of-apoptosis protein 1/2, Bcl-2, Bcl-xL, FADD-like interleukin-1betaconverting enzyme/caspase-8 inhibitory protein, TNF receptor-associated factor-1, and survivin) and angiogenesis (vascular endothelial growth factor, cyclooxygenase-2, intercellular adhesion molecule, and matrix metalloproteinase-9) was also down-regulated by Zyflamend. This correlated with potentiation of cell death induced by TNF and chemotherapeutic agents. Overall, our results indicate that Zyflamend suppresses osteoclastogenesis, inhibits invasion, and potentiates cytotoxicity through down-regulation of NF-kappa B activation and NF-kappa B-regulated gene products.
 ...
PMID:Zyflamend, a polyherbal preparation, inhibits invasion, suppresses osteoclastogenesis, and potentiates apoptosis through down-regulation of NF-kappa B activation and NF-kappa B-regulated gene products. 1751 65

Statins are a class of low molecular weight drugs that inhibit the rate-limiting enzyme of the mevalonate pathway 3-hydroxy-3-methylglutaryl-CoA reductase. Statins have been approved and effectively used to control hypercholesterolemia in clinical setting. Recent study showed statin's antitumor activity and suggested a potential role for prevention of human cancers. In this study, we did cell viability, DNA fragmentation, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays to evaluate the action of statins on prostate cancer cells and used Western blotting and RhoA activation assay to investigate the underlying molecular mechanism of action. Our data showed that lovastatin and simvastatin effectively decreased cell viability in three prostate cancer cell lines (PC3, DU145, and LnCap) by inducing apoptosis and cell growth arrest at G(1) phase. Both lovastatin and simvastatin induced activation of caspase-8, caspase-3, and, to a lesser extent, caspase-9. Both statins suppressed expression of Rb, phosphorylated Rb, cyclin D1, cyclin D3, CDK4, and CDK6, but induced p21 and p27 expression in prostate cancer cells. Furthermore, lovastatin and simvastatin suppressed RhoA activation and c-JUN expression, but not cyclooxygenase-2 expression. Our data showed that the antitumor activity of statins is due to induction of apoptosis and cell growth arrest. The underlying molecular mechanism of statin's action is mediated through inactivation of RhoA, which in turn induces caspase enzymatic activity and/or G(1) cell cycle. Future studies should focus on examining statins and other apoptosis-inducing drugs (e.g., cyclooxygenase-2 inhibitors or curcumin) together to assess their efficacy in prevention of prostate cancer.
 ...
PMID:Statin induces apoptosis and cell growth arrest in prostate cancer cells. 1819 14


1 2 3 4 Next >>