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)

p21-activated protein kinase gamma-PAK (Pak2, PAK I) is cleaved by CPP32 (caspase 3) during apoptosis and plays a key role in regulation of cell death. In vitro, CPP32 cleaves recombinant gamma-PAK into two peptides; 1-212 contains the majority of the regulatory domain whereas 213-524 contains 34 amino acids of the regulatory domain plus the entire catalytic domain. Following cleavage, both peptides become autophosphorylated with [gamma-32P]ATP. Peptide 1-212 migrates at 27,000 daltons (p27) upon SDS-polyacrylamide gel electrophoresis and at 32,000 daltons following autophosphorylation on serine (p27P); the catalytic subunit migrates at 34,000 daltons (p34) before and after autophosphorylation on threonine. Following caspase cleavage, a significant lag (approximately 5 min) is observed before autophosphorylation and activity are detected. When gamma-PAK is autophosphorylated with ATP(Mg) alone and then cleaved, only p27 contains phosphate, and the enzyme is inactive with exogenous substrate. After autophosphorylation of gamma-PAK in the presence of Cdc42(GTPgammaS) or histone 4, both cleavage products contain phosphate and gamma-PAK is catalytically active. Mutation of the conserved Thr-402 to alanine greatly reduces autophosphorylation and protein kinase activity following cleavage. Thus activation of gamma-PAK via cleavage by CPP32 is a two-step mechanism wherein autophosphorylation of the regulatory domain is a priming step, and activation coincides with autophosphorylation of the catalytic domain.
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PMID:Cleavage and activation of p21-activated protein kinase gamma-PAK by CPP32 (caspase 3). Effects of autophosphorylation on activity. 978 69

We previously demonstrated that Caspase-3 is highly expressed in dorsal root ganglia and trigeminal ganglia of mouse embryos [T. Mukasa, K. Urase, Y.M. Momoi, I. Kimura, T. Momoi, Specific expression of CPP32 in sensory neurons of mouse embryos and activation of CPP32 in the apoptosis induced by a withdrawal of NGF, Biochem. Biophys. Res. Commun., 231 (1997) 770-774.]. Since, however, Caspases are processed into active form during apoptosis, it is difficult to examine the involvement of activated Caspases in naturally occurring cell death during development by immunohistochemical staining or in situ hybridization method. We prepared a cleavage site-directed antiserum against Caspase-3 (anti-p20/17). This antiserum reacted with fragment (p20/17) of Caspase-3, but not proCaspase-3 (p32), proCaspase-7 (p34) and its cleaved fragment (p24). We examined the relationship between the activation of Caspase-3 and the appearance of the naturally occurring apoptotic cells in the nervous system during development. In the trigeminal ganglia and dorsal root ganglia, the expression of Caspase-3 mRNA was maximal before the appearance of p20/17-positive cells and apoptotic cells. In the mouse brain, many p20/17-positive cells and apoptotic cells were observed in the neuroepithelium in the early developmental stages, but very few p20/17-positive cells were detected in postmitotic neurons in the cerebral cortex although Caspase-3 mRNA was expressed highly. Caspase-3 is activated mainly during apoptosis of neuroepithelial cells in the early developmental stages but not of mature neurons at postnatal stages.
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PMID:Detection of activated caspase-3 (CPP32) in the vertebrate nervous system during development by a cleavage site-directed antiserum. 980

The antimicrotubule anticancer drug, Taxol, suppresses microtubule dynamics, causes mitotic arrest, and induces caspase-3 cleavage and activity resulting in apoptosis of human AML HL-60 cells. Caspase-3 cleavage is triggered by the mitochondrial release and cytosolic accumulation of the electron transfer protein, cytochrome c (cyt c). Taxol-induced G2/M transition is mediated by p34(cdc-2) (CDK1) which, if prematurely activated, may also trigger apoptosis. In the present studies following S-phase synchronization and release, HL-60 cells with enforced expression of the bcl-xL (HL-60/Bcl-xL) and/or neomycin resistance gene (HL-60/neo) were exposed to Taxol to examine CDK1-related cell-cycle events and the cyt c-triggered molecular cascade of apoptosis. At various time-intervals after Taxol treatment, immunoblot analyses of cyclin B1 and CDK1 levels were performed. In addition, the in vitro histone H1 kinase activity of immunoprecipitated CDK1 and its tyrosine phosphorylation status (by anti-phosphotyrosine immunoblot analysis) were determined. Data presented here show that, while Taxol-induced peak CDK1 kinase activity occurs earlier in HL-60/neo cells, there are no significant differences in cyclin B1 accumulation, tyrosine dephosphorylation of CDK1, and mitotic arrest of Taxol-treated HL-60/neo vs HL-60/Bcl-xL cells. Taxol-induced CDK1 activation and mitosis preceded the cytosolic accumulation (approximately six-fold) of cyt c. The latter event was blocked by Bcl-xL overexpression but not by inhibitors of caspase-3. Although the caspase inhibitors and high Bcl-xL levels inhibited caspase-3 cleavage and activity, they did not significantly affect Taxol-induced CDK1 activation or mitotic arrest. These findings indicate that Bcl-xL overexpression does not affect Taxol-induced CDK1 activity leading to G2/M transition, which temporally precedes the cytosolic cyt c-mediated cleavage and activity of caspase-3 and apoptosis.
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PMID:Temporal relationship of CDK1 activation and mitotic arrest to cytosolic accumulation of cytochrome C and caspase-3 activity during Taxol-induced apoptosis of human AML HL-60 cells. 984 22

Epidemiological and clinical data suggest that selenium may prevent prostate cancer, but the biological effects of selenium on normal or malignant prostate cells are not well known. We evaluated the effects of sodium selenite (Na2SeO3) or l-selenomethionine (SeMet) on monolayer and anchorage-independent growth in a series of normal primary prostate cultures (epithelial, stromal, and smooth muscle) and prostate cancer cell lines (LNCaP, PC-3, and DU145). We observed differential, dose-dependent growth inhibition and apoptosis within prostate cancer cells (compared with normal prostate cells) treated with 1-500 microM of Na2SeO3 or SeMet. Na2SeO3 more potently inhibited growth at any given concentration. The androgen-responsive LNCaP cells were the most sensitive to selenium growth suppression (IC50s at 72 h for Na2SeO3 and SeMet were 0.2 and 1.0 microM, respectively). Growth of the primary prostate cells virtually was not suppressed (IC50s at 72 h for Na2SeO3 and SeMet were 22-38 and >500 microM, respectively). We also observed that DNA condensation and DNA fragmentation (terminal deoxynucleotidyltransferase dUTP nick end labeling/fluorescence-activated cell sorting) were elevated in selenium-treated cells and that activated caspase-3 colocalized with terminal deoxynucleotidyltransferase dUTP nick end labeling-stained cells by immunofluorescence. Higher basal poly(ADP-ribose) polymerase (PARP) expression levels and PARP cleavage (a substrate for caspase-3) were observed during apoptosis in tumor cells, compared with normal cells. Selective tumor cell death was associated with an increase in sub-G0-G1 cells after propidium iodide staining and fluorescence-activated cell sorting analysis. SeMet caused an increase in arrest in the G2-M phase of the cell cycle selectively in cancer cells. Inhibition of cancer cell growth by SeMet was associated with phosphorylation of P-Tyr15-p34/cdc2, which caused growth arrest in the G2-M phase. Anchorage-independent growth of prostate cancer cells in soft agar was sensitive to selenium. Our results suggest that Na2SeO3 is the more potent inducer of apoptosis in normal and cancer prostate cells. Our SeMet results involving PARP and G2-M cell-cycle arrest (cited above) indicate that SeMet selectively induces apoptosis in cancer but not primary cells of the human prostate. Our overall findings are relevant to the molecular mechanisms of selenium actions on prostate carcinogenesis and help demonstrate the selective, dose-dependent effects of selenium (especially SeMet) on prostate cancer cell death and growth inhibition.
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PMID:Selenium effects on prostate cell growth. 1109 24

The pathogenic bacterium Helicobacter pylori produces the cytotoxin VacA, which is implicated in the genesis of gastric epithelial lesions. By transfect ing HEp-2 cells with DNAs encoding either the N-terminal (p34) or the C-terminal (p58) fragment of VacA, p34 was found localized specifically to mitochondria, whereas p58 was cytosolic. Incubated in vitro with purified mitochondria, VacA and p34 but not p58 translocated into the mitochondria. Microinjection of DNAs encoding VacA-GFP and p34-GFP, but not GFP-VacA or GFP-p34, induced cell death by apoptosis. Transient transfection of HeLa cells with p34-GFP or VacA-GFP induced the release of cytochrome c from mitochondria and activated the executioner caspase 3, as determined by the cleavage of poly(ADP-ribose) polymerase (PARP). PARP cleavage was antagonized specifically by co-transfection of DNA encoding Bcl-2, known to block mitochondria-dependent apoptotic signals. The relevance of these observations to the in vivo mechanism of VacA action was supported by the fact that purified activated VacA applied externally to cells induced cytochrome c release into the cytosol.
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PMID:The N-terminal 34 kDa fragment of Helicobacter pylori vacuolating cytotoxin targets mitochondria and induces cytochrome c release. 1110 9

2-Methoxyestradiol (2-ME), an endogenous metabolite of 17beta-estradiol, is present in human blood and urine. Here we show for the first time that 2-ME significantly inhibited the growth of normal prostate epithelial cells and androgen-dependent LNCaP and androgen-independent DU145 prostate cancer cells. This growth inhibition was accompanied by a twofold increase in the G(2)/M population, with a concomitant decrease in the G(1) population, as shown by cell-cycle analysis. 2-ME treatment affected the cell-cycle progression of prostate cancer cells specifically by blocking cells in the G(2) phase. Immunoblot analysis of the key cell-cycle regulatory proteins in the G(2)/M phase showed a 14-fold increase in the expression of p21 and an eightfold increase in the expression of p34 cell division cycle 2 (cdc2). We also found an accumulation of phosphorylated cdc2 after 2-ME treatment. Furthermore, Wee 1 kinase was detectable after 2-ME treatment. 2-ME treatment also led to an increase in the activity of caspase-3, followed by apoptosis, as shown by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate-biotin nick end-labeling and fluorescein isothiocyanate-poly(ADP-ribose) polymerase assay. Estrogen receptor levels did not change after treatment with 2-ME. Examination of the signaling pathways that mediate 2-ME-induced apoptosis showed reduction in the level of p53 expression and its DNA-binding activity. Given the fact that p53 mutations are common in patients with metastatic prostate cancer, our finding that 2-ME-mediated growth inhibition of human prostate cancer cells occurred in a p53-independent manner has considerable clinical significance. These findings, combined with the limited toxicity of 2-ME, may have significant implications for alternative treatment of advanced prostate cancer.
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PMID:2-methoxyestradiol blocks cell-cycle progression at G(2)/M phase and inhibits growth of human prostate cancer cells. 1147 20

Arsenic trioxide (As(2)O(3)) has been found to induce apoptosis in leukemia cell lines and clinical remissions in patients with acute promyelocytic leukemia. In this study, we investigated the cytotoxic effect and mechanisms of action of As(2)O(3) in human tumor cell lines. As(2)O(3) caused inhibition of cell growth (IC(50) range, 3-14 microM) in a variety of human solid tumor cell lines, including four human non-small-cell lung cancer cell lines (H460, H322, H520, H661), two ovarian cancer cell lines (SK-OV-03, A2780), cervical cancer HeLa, and breast carcinoma MCF-7, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry analysis showed that As(2)O(3) treatment resulted in a time-dependent accumulation of cells in the G(2)/M phase. We observed, using Wright-Giemsa and 4',6-diamidine-2-phenylindole-dihydrochloride staining, that As(2)O(3) blocked the cell cycle in mitosis. In vitro examination revealed that As(2)O(3) markedly promoted tubulin polymerization without affecting GTP binding to beta-tubulin. Immunocytochemical and EM studies of treated MCF-7 cells showed that As(2)O(3) treatment caused changes in the cellular microtubule network and formation of polymerized microtubules. Similar to most anti-tubulin agents, As(2)O(3) treatment induced up-regulation of the cyclin B1 levels and activation of p34(cdc2)/cyclinB1 kinase, as well as Bcl-2 phosphorylation. Furthermore, activation of caspase-3 and -7 and cleavage of poly(ADP-ribose) polymerase and beta-catenin occurred only in As(2)O(3)-induced mitotic cells, not in interphase cells, suggesting that As(2)O(3)-induced mitotic arrest may be a requirement for the activation of apoptotic pathways. In addition, As(2)O(3) exhibited similar inhibitory effects against parental MCF-7, P-glycoprotein-overexpressing MCF-7/doxorubicin cells, and multidrug resistance protein (MRP)-expressing MCF-7/etoposide cells (resistance indices, 2.3 and 1.9, respectively). Similarly, As(2)O(3) had similar inhibitory effect against parental ovarian carcinoma A2780 cells and tubulin mutation paclitaxel-resistant cell lines PTx10 and PTx22 (resistance indices, 0.86 and 0.93, respectively), suggesting that its effect on tubulin polymerization and G(2)/M phase arrest is distinct from that of paclitaxel. Taken together, our data demonstrate that As(2)O(3) has a paclitaxel-like effect, markedly promotes tubulin polymerization, arrests cell cycle at mitosis, and induces apoptosis. In addition, As(2)O(3) is a poor substrate for transport by P-glycoprotein and MRP, and non-cross-resistant with paclitaxel resistant cell lines due to tubulin mutation, suggesting that As(2)O(3) may be useful for treatment of human solid tumors, particularly in patients with paclitaxel resistance.
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PMID:Arsenic trioxide produces polymerization of microtubules and mitotic arrest before apoptosis in human tumor cell lines. 1218 29

The role of caspases and calpains in neurodegeneration remains unclear. In this study, we focused on these proteases in a rat model of Huntington's disease using the mitochondrial toxin 3-nitropropionic acid (3NP). Results showed that 3NP-induced death of striatal neurons was preceded by cytochrome c redistribution, transient caspase-9 processing, and activation of calpain, whereas levels of the active/processed form of caspase-3 remained low and were even reduced as compared with control animals. We evidenced here that this decrease in active caspase-3 levels could be attributed to calpain activation. Several observations supported this conclusion. 1) Pharmacological blockade of calpain in 3NP-treated rats increased the levels of endogenous processed caspase-9 and caspase-3. 2) Cell-free extracts prepared from the striatum of 3NP-treated rats degraded in vitro the p34 and p20 subunits of active recombinant caspase-9 and caspase-3, respectively. 3) This degradation of p34 and p20 could be mimicked by purified mu-calpain and was prevented by calpain inhibitors. 4) mu-Calpain produced a loss of the DEVDase (Asp-Glu-Val-Asp) activity of active caspase-3. 5) Western blot analysis and experiments with 35S-radiolabeled caspase-3 showed that mu-calpain cleaved the p20 subunit of active caspase-3 near its catalytic site. 6) mu-Calpain activity was selectively inhibited (IC50 of 100 mum) by a 12 amino acid peptide corresponding to the C terminus of p20. Our results showed that calpain can down-regulate the caspase-9/caspase-3 cell death pathway during neurodegeneration due to chronic mitochondrial defects in vivo and that this effect may involve, at least in part, direct cleavage of the caspase-3 p20 subunit.
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PMID:In vivo calpain/caspase cross-talk during 3-nitropropionic acid-induced striatal degeneration: implication of a calpain-mediated cleavage of active caspase-3. 1291 35

beta-Phenylethyl isothiocyanate (PEITC) is a promising chemoprotective compound that is routinely consumed in the diet as its glucosinolate precursor. Previous studies have shown that PEITC can inhibit phase I enzymes and induce phase II detoxification enzymes along with apoptosis in vitro. The detailed mechanisms involved in the apoptotic cascade, however, have not been elucidated. In the present study, we demonstrate that PEITC can induce apoptosis in hepatoma HepG2 cells in a concentration- and time-dependant manner as determined by TUNEL positive and SubG1 population analysis. Caspase-3-like activity and poly(ADP-ribosyl)polymerase cleavage increased during treatment with 20 microM PEITC; high concentrations, however, induced necrosis. Pre-treatment with Z-VAD-FMK and the caspase-3-specific inhibitor Ac-DEVD-CHO prevented PEITC-induced apoptosis, as determined by caspase-3-like activity and DNA fragmentation. Additional investigations also showed that at concentrations of 5-10 microM PEITC, DNA synthesis was inhibited and G2/M phase cell cycle arrest occurred, correlating with an alteration in cyclin B1 and p34(cdc2) protein levels. Furthermore, we also demonstrate a concentration- and time-dependant burst of superoxide (O2*-) in PEITC-treated cells. However, pre- and co-treatment with the free radical scavengers Trolox, ascorbate, mannitol, uric acid and the superoxide mimetic manganese (III) tetrakis (N-methyl-2-pyridyl) porphyrin failed to prevent PEITC-mediated apoptosis. Taken together, these results suggest that PEITC potently induces apoptosis and cell cycle arrest in HepG2 cells and that the generation of reactive oxygen species appears to be a secondary effect.
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PMID:beta-Phenylethyl isothiocyanate-mediated apoptosis in hepatoma HepG2 cells. 1294 35

Interactions between the histone deacetylase inhibitors (HDACIs) suberoylanilide hydroxamic acid (SAHA) and sodium butyrate (SB) and the heat shock protein (Hsp) 90 antagonist 17-allylamino-17-demethoxygeldanamycin (17-AAG) have been examined in human leukemia cells (U937). Coadministration of marginally toxic concentrations of 17-AAG with sublethal concentrations of SB or SAHA resulted in highly synergistic induction of mitochondrial damage (i.e., cytochrome c release), caspase-3 and -8 activation, and apoptosis. Similar interactions were noted in human promyelocytic (HL-60) and lymphoblastic (Jurkat) leukemia cells. These events were accompanied by multiple perturbations in signal transduction, cell cycle, and survival-related pathways, including early down-regulation of Raf-1, inactivation of extracellular signal-regulated kinase (ERK) 1/2 and mitogen-activated protein/ERK kinase (MEK) 1/2, diminished expression of phospho-Akt, and late activation of c-Jun-NH(2)-terminal kinase, but no changes in expression of phospho-p38 mitogen-activated protein kinase. Coadministration of 17-AAG blocked SAHA-mediated induction of the cyclin-dependent kinase inhibitor p21(CIP1) and resulted in reduced expression of p27(KIP1) and p34(cdc2). 17-AAG/SAHA-treated cells also displayed down-regulation of the antiapoptotic protein Mcl-1 and evidence of Bcl-2 cleavage. Enforced expression of doxycycline-inducible p21(CIP1) or constitutively active MEK1 significantly diminished 17-AAG/SAHA-mediated lethality, indicating that interference with ERK activation and p21(CIP1) induction play important functional roles in the lethal effects of this regimen. In contrast, enforced expression of constitutively active Akt failed to exert cytoprotective actions. Together, these findings indicate that coadministration of SAHA or SB with the Hsp90 antagonist 17-AAG in human leukemia cells leads to multiple perturbations in signaling, cell cycle, and survival pathways that culminate in mitochondrial injury and apoptosis. They also raise the possibility that combining such agents with Hsp90 antagonists may represent a novel antileukemic strategy.
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PMID:Coadministration of the heat shock protein 90 antagonist 17-allylamino- 17-demethoxygeldanamycin with suberoylanilide hydroxamic acid or sodium butyrate synergistically induces apoptosis in human leukemia cells. 1467 5


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