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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
c-Myc is a transcriptional activator implicated in the control of cell proliferation, differentiation and transformation, but is also involved in the regulation of programmed cell death, apoptosis. Despite intensive research, the molecular mechanisms by which c-Myc triggers and executes cell death remain still elusive. Here, we made use of Rat 1A MycER cells expressing a conditionally active c-Myc protein and tested first the hypothesis that
ornithine decarboxylase
(
ODC
), which is a transcriptional target of c-Myc, were a mediator of c-Myc-induced apoptosis. However, our results show that the activity of
ODC
is not required for the c-Myc-mediated apoptosis to occur in these cells. We also found that the expression of p53, p21waf1/cip1, Bcl-2, Bax, Bcl-xL, Bad and cyclins D1, E, A and B did not show any significant changes following c-Myc induction. But, our studies revealed that the c-Myc induced apoptosis is associated with a specific cleavage of poly(ADPribose) polymerase (PARP), suggesting that a cysteine protease of the ICE/CED-3 family is involved. Moreover, we found that the
cysteine protease CPP32
/
Caspase-3
, which is known to cleave PARP, is processed from its inactive form to an active protease composed of 17 and 12 kDa subunits; whilst Ich-1/Caspase-2 belonging to another subset of this protease family was not processed/ activated following c-Myc activation. The activation of CPP32 and apoptotic cell death were inhibited by addition of Z-VAD-fmk, a universal inhibitor of ICE-like proteases. Further, a selective inhibitor of CPP32-like proteases (Z-DEVD-fmk) partly inhibited apoptosis. These results provide evidence that the ICE/CED3-family proteases, CPP32 and likely others, play a critical role in the execution of a nuclear proto-oncogene, c-Myc-induced apoptosis.
...
PMID:Involvement of CPP32/Caspase-3 in c-Myc-induced apoptosis. 946 64
The polyamines spermidine, spermine, and their precursor putrescine are essential for cell growth and the regulation of the cell cycle. Recent studies suggest that excessive accumulation of polyamines favors either malignant transformation or apoptosis, depending on the cell type and the stimulus. This study examines the involvement of polyamines in the induction of apoptosis by the DNA topoisomerase I inhibitor, camptothecin. In IEC-6 cells, camptothecin induced apoptosis within 6 h, accompanied by detachment of cells. Detached cells showed DNA laddering and
caspase 3
induction, characteristic features of apoptosis. Depletion of putrescine, spermidine, and spermine by DL-alpha-difluoromethylornithine (DFMO), a specific inhibitor of
ornithine decarboxylase
(
ODC
) that is the first rate-limiting enzyme for polyamine biosynthesis, decreased the apoptotic index. Delayed apoptosis was accompanied by a decrease in
caspase 3
activity in polyamine-depleted cells. Addition of putrescine restored the induction of apoptosis as indicated by an increase in the number of detached cells and
caspase 3
activity. Polyamine depletion did not change the level of
caspase 3
protein. Inhibition of S-adenosylmethionine decarboxylase by a specific inhibitor [diethylglyoxal bis-(guanylhydrazone); DEGBG] led to depletion of spermidine and spermine with a significant accumulation of putrescine and induction of
ODC
. The DEGBG-treated cells showed an increase in apoptosis, suggesting the importance of putrescine in the apoptotic process. Addition of putrescine to DFMO-treated cell extracts did not increase
caspase 3
activity. The above results indicate that polyamine depletion delays the onset of apoptosis in IEC-6 cells and confers protection against DNA damaging agents, suggesting that polyamines might be involved in the caspase activating signal cascade.
...
PMID:Polyamine depletion delays apoptosis of rat intestinal epithelial cells. 1071 36
Elimination of neurons produced in excess naturally occurs during brain development through programmed cell death. Among the many survival factors affecting this process, a role for neurotransmitters acting on specific receptors has been suggested. We have performed an in vivo pharmacological blockade of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors, using the competitive NMDA receptor antagonist CGP 39551 at developmental stages corresponding to those at which a survival dependence on the stimulation of this receptor has been demonstrated for cerebellar granule neurons explanted in culture (typically from postnatal day 7 to postnatal day 11 or 13). We were able to demonstrate an increased level of DNA fragmentation in the cerebellum of the treated rats. At the P11 stage, in particular, the fragmented DNA extracted from the cerebellum of CGP 39551-treated pups showed a clear laddering of nucleosomal fragments after agarose-gel electrophoresis. Accordingly, in situ TUNEL technique showed a remarkable increase of cells positive for nucleosomal DNA fragmentation, particularly in the inner granular layer of the cerebellum of treated rats at P11 stage. Therefore, the natural rate of apoptotic elimination of cerebellar granule neurons is considerably enhanced under conditions of pharmacological blockade of the NMDA receptor, thus demonstrating, for the first time in vivo, a clear survival dependence of these neurons upon the stimulation of the NMDA receptor. Concomitantly with the increased rate of apoptotic elimination of granule neurons, the activity of two death proteases of the caspase family, in particular of
caspase 3
and caspase 1 at a lower extent, was remarkably increased in the cerebellum of the treated rats. On the contrary, a marker related to the normal differentiation process of granule neurons, the enzyme
ornithine decarboxylase
, was strongly decreased in its activity in the cerebellum of treated rat pups.
...
PMID:Blockade of the NMDA receptor increases developmental apoptotic elimination of granule neurons and activates caspases in the rat cerebellum. 1099 95
The efficacy of the antitumor activity of 1'-acetoxychavicol acetate (ACA), reported to be a suppressor of chemically induced carcinogenesis, was evaluated in Ehrlich ascites tumor cells. ACA treatment resulted in changes in morphology and a dose-dependent suppression of cell viability. Apoptosis, characterized by nuclear condensation, membrane blebbing, cell shrinkage and a significant induction of
caspase-3
-like protease activity at 8 h in a time-course study were observed. Formation of apoptotic bodies was preceded by lowering of intracellular polyamines, particularly putrescine, and both dose- and time-dependent inhibitory and activation effect by ACA on
ornithine decarboxylase
(
ODC
) and spermidine/spermine N(1)-acetyltransferase (SSAT), respectively. Administration of exogenous polyamines prevented ACA-induced apoptosis represented by a reduction in the number of apoptotic bodies and also caused reduction in the induced
caspase-3
-like protease activity at 8 h. These findings suggest that the anticarcinogenic effects of ACA might be partly due to perturbation of the polyamine metabolic pathway and triggering of
caspase-3
-like activity, which result in apoptosis.
...
PMID:Apoptosis induced by 1'-acetoxychavicol acetate in Ehrlich ascites tumor cells is associated with modulation of polyamine metabolism and caspase-3 activation. 1113 3
Intestinal mucosal growth is a common, but uncharacterized, observation associated with diabetes mellitus. Epithelial homeostasis is balanced by regulation of cell proliferation and cell death. To determine the contribution of apoptosis to the overall maintenance of intestinal growth, we examined intestinal apoptosis in the well-characterized streptozotocin (STZ)-induced diabetes rat model. Rats were injected with STZ (75 mg/kg body weight), thereafter they were allowed free feeding or restricted feeding for 3 weeks. Food intake and intestinal mucosal height were evaluated. In a second experiment, additional groups of animals were injected with STZ and were fed ad libitum for 1 or 3 weeks.
Ornithine decarboxylase
(
ODC
) activity, ratio of fragmented DNA to total DNA, electrophoresis of fragmented DNA, and Western blot analysis of
caspase-3
were examined. Food intake gradually increased in free-feeding rats after induction of diabetes. Intestinal mucosal height in free-feeding diabetic rats was approximately 25% longer than controls, but this increase in mucosal height was not observed in restricted-fed diabetic rats (25 g/d).
ODC
activity in intestinal mucosa in diabetic rats did not differ from that of control rats. Percent fragmented DNA of diabetic rats 1 week after STZ injection was significantly lower than that of control rats, and this decrease returned to the control level 3 weeks after STZ treatment. Active form of
caspase-3
was attenuated 1 week after drug treatment. Attenuated effect of diabetic rats on intestinal apoptosis did not affect increased apoptosis after ischemia-reperfusion. Suppression of apoptosis in the early days of STZ-induced diabetes was responsible for the increased mucosal height in the small intestine in STZ-induced diabetic animals.
...
PMID:Suppression of apoptosis is responsible for increased thickness of intestinal mucosa in streptozotocin-induced diabetic rats. 1123 Jul 75
We reported previously that the mechanism by which Green tea extract (GTE) elicited growth-inhibitory effects in Ehrlich ascites tumor cells involved a decrease in
ornithine decarboxylase
(
ODC
) activity and in cell viability. Decrease in
ODC
activity has been associated with apoptotic cell death and we therefore studied changes in cytochrome c release and caspase activation, which characterize apoptosis. GTE caused a dose- and time-dependent increase in
caspase-3
-like protease activation, preceded by a release of cytochrome c from the mitochondria. Inhibiting the activation of
caspase-3
with acetyl-Asp-Glu-Val-Asp-alpha-aldehyde (caspase inhibitor) caused a reversal in the effect on cell viability.
...
PMID:Growth inhibitory effect of green tea extract in Ehrlich ascites tumor cells involves cytochrome c release and caspase activation. 1129 81
We have shown previously that (NOHA) an intermediate in the nitric oxide (NO) synthetic pathway and an inhibitor of arginase significantly reduced intracellular polyamines, activated
caspase-3
and induced apoptosis in the human breast cancer cell line MDA-MB-468. These actions of NOHA were abolished in the presence of exogenous L-ornithine suggesting that a reduction in the intracellular polyamine content might be responsible for the activation of
caspase-3
and apoptotic actions of NOHA. In order to further explore this possibility, we used SAM-486A and alpha-difluoromethylornithine (DFMO), which are inhibitors of S-adenosylmethionine decarboxylase (SAMDC), and
ornithine decarboxylase
(
ODC
), respectively, either alone or in combination to reduce the intracellular polyamine levels. We then assessed whether a reduction in polyamine levels by these two compounds to a similar degree to that produced by NOHA activated
caspase-3
which occurs prior to the onset of apoptosis. We observed that both SAM-486A and DFMO, either alone or in combination, inhibited cell proliferation, induced p21 and arrested cells in the G(0)-G(1) phase of the cell cycle but failed to activate
caspase-3
as assessed by enzymatic assay of
caspase-3
, western blot analysis of the proteolytic cleavage of
caspase-3
protein as well as TUNEL assay. Furthermore, pre-incubation of the cells with SAM-486A and DFMO for 4 days, either alone or in combination significantly inhibited the activation of
caspase-3
and apoptosis by NOHA when compared with that observed with cells treated with NOHA alone. Our results, therefore, indicate that the activation of
caspase-3
and apoptosis observed with NOHA cannot be solely explained by a reduction in intracellular polyamine levels and that other mechanisms need to be also considered.
...
PMID:Activation of caspase-3 activity and apoptosis in MDA-MB-468 cells by N(omega)-hydroxy-L-arginine, an inhibitor of arginase, is not solely dependent on reduction in intracellular polyamines. 1169 50
Polyamines, namely putrescine, spermidine, and spermine, are essential for cell survival and proliferation. A decrease in intracellular polyamine levels is associated with apoptosis. In this study, we used inhibitors of polyamine biosynthesis to examine the effect of polyamine depletion. A combination of inhibitors of
ornithine decarboxylase
, S-adenosylmethionine decarboxylase, or spermidine synthase decreased intracellular polyamine levels and induced cell death in a WEHI231 murine B cell line. These cells exhibited apoptotic features including chromatin condensation and oligonucleosomal DNA fragmentation. Addition of exogenous polyamines reversed the observed features of apoptotic cell death. Similar effects were also observed in other cell lines: a human B cell line Ramos and a human T cell line Jurkat. Depletion of polyamines induced activation of
caspase-3
and disruption of the mitochondrial membrane potential (Delta psi m). Inhibition of caspase activities by an inhibitor prevented the apoptotic nuclear changes but not Delta psi m disruption induced by polyamine depletion. Overexpression of Bcl-xl, an anti-apoptotic Bcl-2 family protein, completely inhibited Delta psi m disruption, caspase activation, and cell death. These results indicate that the depletion of intracellular polyamines triggers the mitochondria-mediated pathway for apoptosis, resulting in caspase activation and apoptotic cell death.
...
PMID:Polyamine depletion induces apoptosis through mitochondria-mediated pathway. 1197 14
We have shown previously that depletion of polyamines delays apoptosis induced by camptothecin in rat intestinal epithelial cells (IEC-6). Mitochondria play an important role in the regulation of apoptosis in mammalian cells because apoptotic signals induce mitochondria to release cytochrome c. The latter interacts with Apaf-1 to activate caspase-9, which in turn activates downstream
caspase-3
. Bcl-2 family proteins are involved in the regulation of cytochrome c release from mitochondria. In this study, we examined the effects of polyamine depletion on the activation of the caspase cascade, release of cytochrome c from mitochondria, and expression and translocation of Bcl-2 family proteins. We inhibited
ornithine decarboxylase
, the first rate-limiting enzyme in polyamine synthesis, with alpha-difluoromethylornithine (DFMO) to deplete cells of polyamines. Depletion of polyamines prevented camptothecin-induced release of cytochrome c from mitochondria and decreased the activity of caspase-9 and
caspase-3
. The mitochondrial membrane potential was not disrupted when cytochrome c was released. Depletion of polyamines decreased translocation of Bax to mitochondria during apoptosis. The expression of antiapoptotic proteins Bcl-x(L) and Bcl-2 was increased in DFMO-treated cells. Caspase-8 activity and cleavage of Bid were decreased in cells depleted of polyamines. These results suggest that polyamine depletion prevents IEC-6 cells from apoptosis by preventing the translocation of Bax to mitochondria, thus preventing the release of cytochrome c.
...
PMID:Polyamine depletion prevents camptothecin-induced apoptosis by inhibiting the release of cytochrome c. 1199 43
Previous studies in our laboratories demonstrated that overexpression of manganese superoxide dismutase (MnSOD) suppressed both the incidence and multiplicity of papillomas in a DMBA/TPA multi-stage skin carcinogenesis model. The activity of activator protein-1 (AP-1), which is associated with tumor promotion, was reduced in MnSOD transgenic mice overexpressing MnSOD in the skin, suggesting that MnSOD may reduce tumor incidence by suppressing AP-1 activation. In the present study, we report that reduction of MnSOD by heterozygous knockout of the MnSOD gene (Sod2 -/+, MnSOD KO) increased the levels of oxidative damage proteins and the activity of AP-1 following TPA treatment. RNA levels of
ornithine decarboxylase
(
ODC
) were also increased, suggesting an increase in cell proliferation in the KO mice. Histological examination confirmed that the number of proliferating cells in DMBA/TPA-treated mouse skin were higher in the KO mice. Interestingly, histological examination also demonstrated greater numbers of apoptotic cells in the KO mice after DMBA/TPA treatment. Evidence of apoptosis, including DNA fragmentation, cytochrome c release from mitochondria, and
caspase 3
activation were also observed by biochemical assays of the skin tissues. Apoptosis was associated with an increase in nuclear levels of p53 as determined by Western analysis. Quantitative immunogold ultrastructural analysis confirmed that p53 immunoreactive protein levels were increased to a greater level in the nuclei of epidermal cells from MnSOD KO mice compared to epidermal nuclei from wild type mice similarly treated. Moreover, p53 levels further increased in the mitochondria of DMBA/TPA treated mice, and this increase was much greater in the MnSOD KO than in the wild type mice, suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Pathological examination reveals no difference in the incidence and frequency of papillomas comparing the KO mice and their wild type littermates. Taken together, these results suggest that: (1) MnSOD deficiency enhanced TPA-induced oxidative stress and AP-1 and p53 levels, consistent with the increase in both proliferation and apoptosis events in the MnSOD KO mice, and (2) increased apoptosis may negate increased proliferation in the MnSOD deficient mice during an early stage of tumor development.
...
PMID:Manganese superoxide dismutase deficiency enhances cell turnover via tumor promoter-induced alterations in AP-1 and p53-mediated pathways in a skin cancer model. 1203 21
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