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)

The molecular mechanisms underlying the cell cycle growth-inhibitory and apoptotic effects of flavopiridol (FP) were determined in human breast cancer cells. Treatment with FP caused accumulation in the G(1) phase of the cell cycle and induced apoptosis of SKBR-3 and MB-468 cells. This was associated with down-regulation of the levels of cyclins D1 and B1, as well as with inhibition of cyclin-dependent kinase (cdk) 1, cdk2, and cdk4. FP-induced apoptosis was accompanied by a conformational change and mitochondrial localization of Bax. This resulted in the accumulations of cytochrome c, Smac, and Omi/HtrA2 in the cytosol and induced the poly(ADP-ribose) polymerase cleavage activity of caspase-3. Treatment with FP also attenuated the mRNA and protein levels of XIAP, cIAP-2, Mcl-1, Bcl-x(L), and survivin. In MB-468 cells with overexpression of Bcl-2 (468/Bcl-2), FP-induced Bax conformational change and apoptosis were inhibited, whereas the FP-mediated decline in the levels of IAP proteins, Mcl-11 and Bcl-x(L) remained unaltered. The effects of cotreatment with FP and the nontaxane tubulin-polymerizing agent epothilone (Epo) B were also determined in MB-468 cells. Sequential treatment with Epo B followed by FP induced significantly more apoptosis of MB-468 cells than treatment with the reverse sequence of FP followed by Epo B or treatment with either agent alone (P < 0.05). Treatment with Epo B followed by FP induced more Bax conformational change and was associated with a greater decline in the levels of XIAP, cIAP-2, Mcl-1, and Bcl-x(L). However, MB-468/Bcl-2 cells remained relatively resistant to Epo B followed by FP. Taken together, these findings suggest that the superior sequence-dependent anti-breast cancer activity of Epo B followed by FP may be due to FP-induced Bax conformational change and down-regulation of the antiapoptotic IAP, Bcl-x(L), and Mcl-1 proteins, but this treatment may not overcome the resistance to apoptosis of breast cancer cells conferred by overexpression of Bcl-2.
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PMID:Flavopiridol down-regulates antiapoptotic proteins and sensitizes human breast cancer cells to epothilone B-induced apoptosis. 1251 83

The naturally occurring cyclic tetrapeptide chlamydocin is a very potent inhibitor of cell proliferation. Here we show that chlamydocin is a highly potent histone deacetylase (HDAC) inhibitor, inhibiting HDAC activity in vitro with an IC(50) of 1.3 nM. Like other HDAC inhibitors, chlamydocin induces the accumulation of hyperacetylated histones H3 and H4 in A2780 ovarian cancer cells, increases the expression of p21(cip1/waf1), and causes an accumulation of cells in G(2)/M phase of the cell cycle. In addition, chlamydocin induces apoptosis by activating caspase-3, which in turn leads to the cleavage of p21(cip1/waf1) into a 15-kDa breakdown product and drives cells from growth arrest into apoptosis. Concomitant with the activation of caspase-3 and cleavage of p21(cip1/waf1), chlamydocin decreases the protein level of survivin, a member of the inhibitor of apoptosis protein family that is selectively expressed in tumors. Although our data indicate a potential link between degradation of survivin and activation of the apoptotic pathway induced by HDAC inhibitors, stable overexpression of survivin does not suppress the activation of caspase-3 or cleavage of p21(cip1/waf1) induced by chlamydocin treatment. The decrease of survivin protein level is mediated by degradation via proteasomes since it can be inhibited by specific proteasome inhibitors. Taken together, our results show that induction of apoptosis by chlamydocin involves caspase-dependent cleavage of p21(cip1/waf1), which is strikingly associated with proteasome-mediated degradation of survivin.
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PMID:Inhibition of histone deacetylases by chlamydocin induces apoptosis and proteasome-mediated degradation of survivin. 1253 46

Neutrophils and monocytes/macrophages are derived from common progenitors, but exhibit markedly different lifespans. Differentiated neutrophils are short-lived and die rapidly by apoptosis, while monocytic cells are longer-lived. In this report we used the HL-60 cell line as a model system to identify differences in apoptotic pathways which might account for the differing lifespans of granulocytic vs monocytic cells. We observed that induction of granulocytic differentiation by retinoic acid led to robust activation of the executioner protease caspase-3, and early onset of apoptosis. By contrast, caspase-3 was not appreciably activated during phorbol 12-myristate 13-acetate (PMA)-induced monocytic differentiation, and apoptosis was delayed in these cells. Since the activation of caspase-3 is inhibited by members of the inhibitor of apoptosis (IAP) and Bcl-2 protein families, we investigated the expression of anti-apoptotic members of these families. Induction of monocytic differentiation led to marked upregulation of the IAP protein XIAP, as well as the Bcl-2 family member Bcl-X(L). During granulocytic differentiation the levels of XIAP progressively declined, while Bcl-X(L) levels remained unchanged. A different IAP protein, survivin, was downregulated during differentiation along either lineage, as was expression of Bcl-2. The upregulation of Bcl-X(L) during monocytic differentiation coincided with phosphorylation/activation of STAT3, a known activator of bcl-X gene transcription. Moreover, Bcl-X(L) upregulation was dependent on MEK/ERK signaling. Upregulation of XIAP proceeded in a MEK/ERK-independent fashion. Treatment with antisense Bcl-X(L) or XIAP oligonucleotides resulted in significant loss of viability in cells differentiating along the monocytic lineage. Together, these findings indicate that the levels of XIAP and Bcl-X(L) are regulated by distinct pathways during monocytic differentiation, and that upregulation of these proteins contributes to the increased longevity of cells in the monocytic lineage.
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PMID:Differential activation of apoptosis regulatory pathways during monocytic vs granulocytic differentiation: a requirement for Bcl-X(L)and XIAP in the prolonged survival of monocytic cells. 1259 39

Laminar shear stress strongly inhibits vascular endothelial cell apoptosis by unknown mechanisms. We reported that shear stress stimulates endothelial cells to produce 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) by elevating the expression level of lipocalin-type prostaglandin D synthase. To investigate the role of 15d-PGJ2 produced in the vascular wall, we examined the effect of 15d-PGJ2 on endothelial cell apoptosis. We induced apoptosis in human umbilical vein endothelial cells (HUVECs) by growth factor deprivation. 15d-PGJ2 strongly inhibited DNA ladder formation, nuclear fragmentation, and caspase-3-like activity in HUVECs. To elucidate the mechanism by which 15d-PGJ2 inhibits endothelial cell apoptosis, we examined expression of the inhibitor of apoptosis proteins (IAP) cellular-IAP1 (c-IAP1), c-IAP2, x-linked IAP, and survivin in HUVECs. In parallel with the inhibition of apoptosis, 15d-PGJ2 elevated the expression level of c-IAP1 protein in a dose- and time-dependent manner without changing the mRNA level. Laminar shear stress also induced c-IAP1 expression. Chase experiments with the use of cycloheximide revealed that 15d-PGJ2 and shear stress both inhibited the proteolytic degradation of c-IAP1 protein. These results suggested that 15d-PGJ2 inhibits endothelial cell apoptosis through, at least in part, c-IAP1 protein stabilization. This mechanism might be involved in the antiapoptotic effect of laminar shear stress.
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PMID:15-deoxy-delta 12,14-prostaglandin J2 and laminar fluid shear stress stabilize c-IAP1 in vascular endothelial cells. 1262 86

Gastric cancer is one of the most common malignant tumors of the gastrointestinal tract. However, the molecular pathways involved in the regulation of gastric carcinogenesis are not completely elucidated. In the last decade, basic cancer research has been focused on the deregulation of apoptosis as a central event in the process of carcinogenesis. Caspase-3 and survivin are regulators of apoptosis and have been implicated in the development of gastric cancer. The aim of the present study was to compare the expression of mRNA and protein for survivin and caspase-3 in the gastric cancer and in the cancer margin with that in normal human gastric mucosa. Fifteen patients with advanced gastric cancer (all H. pylori-positive) and 15 matched control subjects with normal gastric mucosa were included in this study. The biospy specimens for histology and for molecular analyses were taken from gastric tumor, tumor surrounding gastric mucosa and in normal patients from the mucosa of antrum and corpus. Survivin mRNA expression was very weak, but detectable, in the normal gastric mucosa. However, at the protein level, no expression for survivin was detected in the normal gastric mucosa. In the biopsy specimens from tumor and surrounding gastric mucosa, a significant increase in survivin mRNA and protein expression was observed. The expression of survivin was higher in the tumor than in the tumor margin. The mRNA and protein expression of caspase-3 was detected in the gastric mucosa of normal subjects. In gastric cancer only the expression of procaspase-3 was observed, while the expression of active caspase-3 was completely undetectable. In the gastric mucosa surrounding gastric cancer, no gene and protein expression for caspase-3 was detected. We conclude that the changes in the level of caspase-3 and survivin play an important role in the transformation from normal gastric mucosa to gastric career.
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PMID:Expression of survivin and caspase-3 in gastric cancer. 1264 1

Survivin is a structurally unique member of the inhibitors of apoptosis protein family and is involved in the control of cell division and inhibition of apoptosis. The notion that survivin is overexpressed in most human tumors but absent in normal adult tissues with only a few exceptions has led to the proposal of survivin as a promising therapeutic target for novel anticancer therapies. In this context, we generated a hammerhead ribozyme targeting the 3' end of the CUA110 triplet in the survivin mRNA. Two human melanoma cell lines (JR8 and M14) overexpressing survivin were stably transfected with the pRc/CMV vector carrying the ribozyme sequence. Two polyclonal cell populations proven to endogenously express ribozyme and characterized by a markedly lower survivin protein level (-60% and -50%, respectively) than JR8 and M14 parental cells were selected for the study. Ribozyme-expressing cells showed a significantly (p<0.01) increased sensitivity to gamma-irradiation (as detected by clonogenic cell survival) compared to JR8 and M14 cells. Moreover, in the JR8 cell line, the extent of radiation-induced apoptosis (in terms of percentage of apoptotic nuclei in cells stained with propidium iodide and level of caspase-3 catalytic activity) was markedly greater in ribozyme-expressing cells than in parental cells. These results demonstrate for the first time that attenuation of survivin expression renders human melanoma cells more susceptible to gamma-irradiation.
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PMID:Radiosensitization of human melanoma cells by ribozyme-mediated inhibition of survivin expression. 1264 30

High levels of cytokines are associated with a poor prognosis in acute myeloid leukemia (AML). However, cytokines may induce, on one hand, survival factor expression and cell proliferation and, on the other hand, expression of inhibitory signals such as up-regulation of suppressors of cytokine signaling (SOCS) and induce apoptotic cell death. Because blasts from patients with AML express high procaspase protein levels, we asked whether granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances procaspase protein production in AML cells. In the GM-CSF-responsive OCIM2 AML cell line, GM-CSF induced signal transducer and activator of transcription 5 (Stat 5) phosphorylation, up-regulated cyclin D2, and stimulated cell cycle progression. Concurrently, GM-CSF stimulated expression of SOCS-2 and -3 and of procaspases 2 and 3 and induced caspase 3 activation, poly(ADP[adenosine 5'-diphosphate]-ribose) polymerase (PARP) cleavage, and apoptotic cell death. The Janus kinase (Jak)-Stat inhibitor AG490 abrogated GM-CSF-induced expression of procaspase 3 and activation of caspase 3. Under the same conditions GM-CSF up-regulated production of BAX as well as Bcl-2, Bcl-XL, survivin, and XIAP. GM-CSF also increased procaspase 3 protein levels in OCI/AML3 and Mo7e cells, suggesting that this phenomenon is not restricted to a single leukemia cell line. Our data suggest that GM-CSF exerts a dual effect: it stimulates cell division but contemporaneously up-regulates Jak-Stat-dependent proapoptotic proteins. Up-regulation of procaspase levels in AML is thus a beacon for an ongoing growth-stimulatory signal.
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PMID:Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces antiapoptotic and proapoptotic signals in acute myeloid leukemia. 1266 43

Apoptosis is an essential physiologic process used in almost all tissues to remove damaged or superfluous cells. However, the early embryos are unique because no cell death is found up to the blastocyst stage during normal development. Survivin, a member of the IAP family, is capable of binding to caspases to modulate their functions. Here, we investigated the expression of survivin, and its role in preventing apoptosis in mouse preimplantation embryos. Transcripts for survivin and a splice variant lacking exon 2 were detected from unfertilized oocytes up to hatched blastocyst stage. At the protein level, survivin was also detected at all stages of early embryos. The antisense approach was used to demonstrate the role of survivin on embryo development. Development of early embryos treated with antisense survivin oligonucleotides was arrested at the morula or early blastocyst stage with disruption of tubulin formation and abnormal nuclei, associated with apoptosis. The effect of the antisense was enhanced by cotreatment with an apoptosis-inducing reagent, staurosporine. In contrast, apoptosis induced by the antisense treatment was inhibited by caspase-3 and -9 inhibitors. These results indicate that survivin is an essential antiapoptotic gene expressed in preimplantation embryos and could protect the embryos from apoptosis by inhibiting an apoptotic pathway involving caspases.
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PMID:Survivin acts as an antiapoptotic factor during the development of mouse preimplantation embryos. 1267 6

Non-small cell lung cancer (NSCLC) is the most prevalent type of lung cancer especially in India and displays resistance to anticancer treatment. In our earlier study we had isolated a cDNA clone from rat thymocytes induced to undergo apoptosis, which was found to encode S29 ribosomal protein [Biochem. Biophys. Res. Commun. 277 (2000) 476]. In the present study an attempt has been made to find out whether enhanced expression of S29 cDNA can kill NSCLC H520 cells. We found that S29 induced apoptosis and augmented the effect of anticancer drugs. Expressions of several molecular determinants of apoptosis were analyzed in order to understand the mechanism of apoptosis induced by S29. We observed downregulation of the expression of inhibitors of apoptosis proteins (IAPs) Bcl-2, Bcl-X(L), and survivin and upregulation of pro-apoptotic p53 and Bax as assessed by Western blotting. Mitochondrial release of cytochrome c and activation of initiator caspase-8 and -9 and effector caspase-3, followed by cleavage of nuclear substrate poly(ADP-ribose) polymerase, were also observed. Permeability transition as determined by changes in DeltaPsi(m) was not a requirement for cytochrome c release. There was a marginal increase in the release of apoptosis inducing factor (AIF) and reduction of NF-kappaB dependent transcriptional activity. There was non-involvement of calcium and the telomerase activity, a proliferation marker.
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PMID:S29 ribosomal protein induces apoptosis in H520 cells and sensitizes them to chemotherapy. 1270 79

We have reviewed the clinical, morphologic, immunophenotypical, and molecular features of a series of 27 cases of nodal marginal zone lymphoma with the aim of defining this entity more precisely. The series was characterized by a relatively favorable clinical course, with a low clinical stage at diagnosis (59% patients with clinical stage I-II) and a 5-year overall survival probability of 79%. However, the disease persisted in a relatively large fraction of the patients, thus yielding a 5-year failure-free survival probability of 22%. Molecular and immunohistochemical analyses of the series revealed heterogeneity in the frequency of IgV(H) somatic mutation and in the expression of IgD, CD43, MUM1, and CD38. Apart from the absence of nuclear Bcl10, no clear distinction could be made from the expression profiling of other B-cell lymphomas claimed to be derived from marginal zone B cells. Additionally, the immunophenotype of the tumoral cells in all cases but one differed from that described in monocytoid B cells. It was characterized by a Bcl2-, p21+, cyclin E+ profile. The analysis of apoptosis-regulator proteins disclosed abnormalities in the expression of survivin and active caspase 3, which could partially explain the abnormal regulation of apoptosis observed in these tumors. Molecular and immunohistochemical data obtained in this study strongly imply that there is significant heterogeneity among the cases included in the category termed nodal marginal zone lymphoma.
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PMID:Nodal marginal zone lymphoma: a heterogeneous tumor: a comprehensive analysis of a series of 27 cases. 1276 79


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