Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Galectin (Gal)-3, a M(r) 31000 member of the beta-galactoside-binding protein family, is a multifunctional protein implicated in a variety of biological functions, including tumor cell adhesion, proliferation, differentiation, angiogenesis, apoptosis, cancer progression, and metastasis. Here, we report that secreted extracellular Gal-3 can signal apoptosis of human T leukemia cell lines, human peripheral blood mononuclear cells, and activated mouse T cells after binding to cell surface glycoconjugate receptors through carbohydrate-dependent interactions because the apoptotic effect was found to be inhibited by lactose, specific sugar inhibitor, and to be dose dependent. However, the apoptosis sensitivity to Gal-3 varied among the different cell lines tested. We report that Gal-3-null Jurkat, CEM, and MOLT-4 cells were significantly more sensitive to exogenous Gal-3 than SKW6.4 and H9 cells, which express Gal-3, suggesting a cross-talk between the antiapoptotic activity of intracellular Gal-3 and proapoptotic activity of extracellular Gal-3. Furthermore, Gal-3-transfected CEM cells were found to be more resistant to C(2)-ceramide-induced apoptosis than the control CEM cells. Identification of Gal-3 cell surface receptors revealed that Gal-3 binding to CD7 and CD29 (beta(1) integrin) induced apoptosis. Gal-3 binding to its cell surface receptors results in activation of mitochondrial apoptosis events including cytochrome c release and caspase-3 activation, but not caspase-8 activation. Taken together, these results suggest that the induction of T-cell apoptosis by secreted Gal-3 may play a role in the immune escape mechanism during tumor progression through the induction of apoptosis to cancer-infiltrating T cells. The induction of T-cell apoptosis by secreted Gal-3 is dependent in part on the presence or absence of cytoplasmic Gal-3, providing a new insight for the immune escape mechanism of cancer cells.
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PMID:CD29 and CD7 mediate galectin-3-induced type II T-cell apoptosis. 1467 89

Carbonic anhydrase-related protein VIII (CA-RP VIII) is expressed in most non-small cell lung cancer, and especially strongly at the front of tumor progression. Screening analysis of CA-RP VIII expression in a panel of cultured lung cancer cell lines showed that a well differentiated adenocarcinoma cell line, PC-9, appeared to lack CA-RP VIII. Subsequently, CA8 cDNA was transfected with an expression vector into PC-9. Ectopic overexpression of CA-RP VIII reduced the growth of PC-9 cells on uncoated culture dishes, especially when the cultures were started at low cell density, but increased cell growth on laminin-coated dishes. Interestingly, ectopic CA-RP VIII expression markedly reduced caspase-3 activity induced by serum starvation and anti-cancer agents in PC-9 cells. The present findings suggest that CA-RP VIII expression promotes progression of lung cancer by multifarious mechanisms.
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PMID:Effect of carbonic anhydrase-related protein VIII expression on lung adenocarcinoma cell growth. 1514 May 39

Tumorigenesis is associated with several changes that alter the cellular susceptibility to programmed cell death. Here, we show that immortalization and transformation sensitize cells in particular to the cysteine cathepsin-mediated lysosomal death pathway. Spontaneous immortalization increased the susceptibility of wild-type murine embryonic fibroblasts (MEFs) to tumor necrosis factor (TNF)-mediated cytotoxicity >1000-fold, whereas immortalized MEFs deficient for lysosomal cysteine protease cathepsin B (CathB) retained the resistant phenotype of primary cells. This effect was specific for cysteine cathepsins, because also lack of cathepsin L (a lysosomal cysteine protease), but not that of cathepsin D (a lysosomal aspartyl protease) or caspase-3 (the major executioner protease in classic apoptosis) inhibited the immortalization-associated sensitization of MEFs to TNF. Oncogene-driven transformation of immortalized MEFs was associated with a dramatic increase in cathepsin expression and additional sensitization to the cysteine cathepsin-mediated death pathway. Importantly, exogenous expression of CathB partially reversed the resistant phenotype of immortalized CathB-deficient MEFs, and the inhibition of CathB activity by pharmacological inhibitors or RNA interference attenuated TNF-induced cytotoxicity in immortalized and transformed wild-type cells. Thus, tumorigenesis-associated changes in lysosomes may counteract cancer progression and enhance therapeutic responses by sensitizing cells to programmed cell death.
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PMID:Sensitization to the lysosomal cell death pathway upon immortalization and transformation. 1528 36

The present study investigated the antiapoptotic effects of estrogen in normal and cancer human cervical cells and the mechanisms involved. Baseline apoptosis in human cervical epithelial cells is mediated predominantly by P2X7-receptor-induced, Ca(2+)-dependent activation of the mitochondrial (caspase-9) pathway. Treatment with 10 nM 17beta-estradiol blocked apoptosis induced by the P2X7-receptor ligands ATP and 2',3'-0-(4-benzoylbenzoyl)-ATP in normal human cervical epithelial cells (hECEs) and attenuated the effect in hECEs immortalized with human papillomavirus-16 (ECE16-1) and the cancer cervical cells HT3 and CaSki. Diethylstilbestrol and to a lesser degree estrone could mimic the effects of 17beta-estradiol, whereas actinomycin-D and cycloheximide attenuated the response. The antiapoptotic effect of estrogen did not depend on cell cycle phase, and in both normal and cancer cervical cells, it involved attenuation of activation of caspase-9 and the terminal caspase-3. However, involvement of cascades upstream to the caspase-9 differed in normal vs. cancer cervical cells. In the normal hECEs estrogen blocked P2X7-receptor-induced calcium influx. In contrast, in the cancer CaSki cells, estrogen up-regulated expression of Bcl-2 and attenuated Ca(2+)-induced mitochondrial swelling (i.e. formation of mitochondrial permeability transition pores). Estrogen had no effect on P2X7-receptor-induced apoptosis in the anaplastic SiHa and Hela cells. These results point to a novel antiapoptotic effect of estrogen in the cervix that is independent of its mitogenic function. The results also suggest that cancer cervical cells evolved antiapoptotic mechanisms that enable the cells to evade apoptosis and could therefore promote tumor progression.
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PMID:Antiapoptotic effects of estrogen in normal and cancer human cervical epithelial cells. 1531 52

The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) induces apoptosis in a variety of human cancer cells including breast carcinoma and this property may be important for its chemopreventive and therapeutic effects. Resistance to 4HPR has been described, however, the molecular mechanisms underlying sensitivity or resistance to this retinoid are not clear. Recently, it has been shown that the carbohydrate-binding protein galectin-3, which has been implicated in tumor progression, contains the anti-death motif NWGR present in the anti-apoptotic protein Bcl-2. To determine whether galectin-3 expression can abrogate the effect of 4HPR, we tested the effects of 4HPR on apoptosis of cell clones derived from the galectin-3 deficient human BT549 breast carcinoma cells after transfection with either wild type galectin-3 (BT549Gal-3Wt), galectin-3 inactivated by a point mutation in the NWGR motif (BT549Gal-3Mu), or empty vector control (BT549Vec). Both BT549Vec and BT549Gal-3Mu cells showed a marked decrease in survival after treatment with 4HPR principally due to induction of apoptosis. 4HPR-induced apoptosis in these cells was associated with stimulation of reactive oxygen species generation, decreased levels of Bcl-2 protein, release of cytochrome c into the cytosol, increased caspase-3 activity, and poly(ADP-ribose) polymerase cleavage. In contrast, 4HPR failed to exert any of these effects in the BT549Gal-3Wt cells. The demonstration that galectin-3 suppresses 4HPR-induced apoptosis in human breast carcinoma cells suggests that the increased expression of galectin-3 during cancer progression may be associated with 4HPR resistance.
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PMID:Inhibition of N-(4-hydroxyphenyl)retinamide-induced apoptosis in breast cancer cells by galectin-3. 1532 75

Mts1 (S100A4) is a calcium-binding protein of the EF-hand type, belonging to the S100 family of proteins. The mts1/S100A4 gene was originally isolated from tumor cell lines, and the protein is believed to play an important role in tumor progression. More recently, oligomeric, but not dimeric, forms of Mts1 have been shown to have a neuritogenic effect when added extracellularly to hippocampal neurons. Here we show increased neurite outgrowth in two other cell types, dopaminergic and cerebellar neurons, in response to treatment with Mts1 oligomers. Moreover, we demonstrate that Mts1 acts as a neuroprotectant in primary cerebellar, dopaminergic, and hippocampal neurons induced to undergo cell death. Interestingly, the survival of the cerebellar and hippocampal neurons increased as a result of treatment with Mts1 not only in oligomeric form but also--although to a lesser extent--in dimeric form. The inhibition of death in cerebellar neurons by Mts1 was accompanied by an inhibition of DNA fragmentation, but Mts1 did not affect the activity of caspases-3 and -6. In hippocampal neurons, cell death induced by the amyloid-beta peptide (Abeta(25-35)) was characterized by an increase in caspase-3 and -6 activity, but no DNA fragmentation was observed. As in cerebellar neurons, the induced increase in caspase activity in hippocampal neurons was not affected by Mts1.
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PMID:The Mts1/S100A4 protein is a neuroprotectant. 1533 97

Heat shock protein 27 (Hsp27) is a chaperone implicated as an independent predictor of clinical outcome in prostate cancer. Our aim was to characterize changes in Hsp27 after androgen withdrawal and during androgen-independent progression in prostate xenografts and human prostate cancer to assess the functional significance of these changes using antisense inhibition of Hsp27. A tissue microarray was used to measure changes in Hsp27 protein expression in 232 specimens from hormone naive and posthormone-treated cancers. Hsp27 expression was low or absent in untreated human prostate cancers but increased beginning 4 weeks after androgen-ablation to become uniformly highly expressed in androgen-independent tumors. Androgen-independent human prostate cancer PC-3 cells express higher levels of Hsp27 mRNA in vitro and in vivo, compared with androgen-sensitive LNCaP cells. Phosphorothioate Hsp27 antisense oligonucleotides (ASOs) and small interference RNA potently inhibit Hsp27 expression, with increased caspase-3 cleavage and PC3 cell apoptosis and 87% decreased PC3 cell growth. Hsp27 ASO and small interference RNA also enhanced paclitaxel chemosensitivity in vitro, whereas in vivo, systemic administration of Hsp27 ASO in athymic mice decreased PC-3 tumor progression and also significantly enhanced paclitaxel chemosensitivity. These findings suggest that increased levels of Hsp27 after androgen withdrawal provide a cytoprotective role during development of androgen independence and that ASO-induced silencing can enhance apoptosis and delay tumor progression.
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PMID:Heat shock protein 27 increases after androgen ablation and plays a cytoprotective role in hormone-refractory prostate cancer. 1537 73

Accumulating evidence suggests that glutamate plays a key role in the proliferation and invasion of glioblastoma tumors. Astrocytic tumors have been shown to release glutamate at high levels, which may stimulate tumor cell proliferation and motility via activation of glutamate receptors. Excess glutamate has also been found to facilitate tumor invasion by causing excitotoxic damage to normal brain thereby paving a pathway for tumor migration. Results from tissue microarray analyses showed decreased excitatory amino acid transporter-2 (EAAT-2) expression in high-grade glial tumors compared with low-grade astrocytomas and normal brain. EAAT-2 expression was inversely correlated with tumor grade, implicating its potential role in glial tumor progression, which was reflected by an undetectable level of EAAT-2 protein in glioma cell lines. In this study, we sought to investigate the effect of reconstituted EAAT-2 on glioma cell growth in vitro and in vivo by adenoviral-mediated gene transfer. Infection of glioma cells with Ad-EAAT-2 resulted in a physiologic level of functional EAAT-2, and a subsequent dose-dependent reduction in cell proliferation in all glioma cell lines tested compared with controls. Interestingly, results from analyses of Annexin V staining, detection of poly(ADP-ribose)polymerase cleavage and caspase-3 activation all indicated that Ad-EAAT-2 infection elicited apoptosis in glioma cells. Ex vivo experiments in nude mice showed a total suppression of tumor growth at sites that received Ad-EAAT-2-infected cells. Collectively, our results uncovered a new function of EAAT-2 in controlling glioma proliferation. Further studies will improve our knowledge of the role of glutamate in glioma growth and may provide useful prognostic information and alternative therapeutic targets for the treatment of glioma.
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PMID:The excitatory amino acid transporter-2 induces apoptosis and decreases glioma growth in vitro and in vivo. 1575 93

Recent studies have shown that resistance to apoptosis may contribute to chemoresistance. Alteration of caspases, such as caspase-3, results on decreased apoptosis. Genes of IAP (inhibitor of apoptosis proteins) family, such as survivin, were also implicated in tumor development where they are mutated or have deregulated expression. Initial studies revealed strong survivin expression in several fetal tissues and some proliferating adult tissues, whereas no survivin expression was detected in a range of adult tissues. Although the factors at the origins on survivin re-expression in tumors are still unknown, the anti-apoptotic function of survivin is mediated in part by inhibiting caspase-3 activity. Recently, functionally divergent splice variants resulting from alternative splicing, with apoptotic (for caspase-3) or anti-apoptotic (for survivin) opposite activities have been described. The alternative splice variant, caspase-3s results from exon 6 deletion and shows antagonist of apoptotic property of caspase-3. Three alternative splice variants of survivin (survivin-DeltaEx3, survivin-2B and survivin-3B) differing in their anti-apoptotic properties were reported. While the anti-apoptotic effect of survivin-DeltaEx3 is preserved, survivin-2B has lost its anti-apoptotic potential and may act as a naturally occurring antagonist of survivin and survivin-DeltaEx3. At present, little is known about properties of survivin-3B. Several evidences indicate that in several cancers, the ratio of splice variants is significantly altered, and modifications of splicing pathways have been developed for cancer treatment. Recent investigations have shown that expression of alternative splice variants of caspase-3 and of survivin were also altered in many human cancers, and that variations in their expression were associated with tumor progression and chemoresistance. In this article, we describe recent data concerning alternative splice variants of these two proteins.
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PMID:[Implication of alternative splice transcripts of caspase-3 and survivin in chemoresistance]. 1582 Sep 16

Bcl-2 and Bcl-xL are associated with treatment resistance and progression in many cancers, including prostate cancer. The objective of this study was to determine whether a novel bispecific antisense oligonucleotide targeting both Bcl-2 and Bcl-xL induces apoptosis and enhances chemosensitivity in androgen-independent PC3 prostate cancer cells. An antisense oligonucleotide with complete sequence identity to Bcl-2 and three-base mismatches to Bcl-xL selected from five antisense oligonucleotides targeting various regions with high homology between Bcl-2 and Bcl-xL was found to be the most potent inhibitor of both Bcl-2 and Bcl-xL expression in PC3 cells. This selected Bcl-2/Bcl-xL bispecific antisense oligonucleotide reduced mRNA and protein levels in a dose-dependent manner, reducing Bcl-2 and Bcl-xL protein levels to 12% and 19%, respectively. Interestingly, Mcl-1 was down-regulated as well, although levels of Bax, Bad, or Bak were not altered after treatment with this bispecific antisense oligonucleotide. Indirect down-regulation of inhibitor of apoptosis (IAP) family, including XIAP, cIAP-1 and cIAP-2, via second mitochondria-derived activator of caspases was also observed after bispecific antisense oligonucleotide treatment. Executioner caspase-3, caspase-6, and caspase-7 were shown to be involved in apoptosis induced by bispecific antisense oligonucleotide. This Bcl-2/Bcl-xL bispecific antisense oligonucleotide also enhanced paclitaxel chemosensitivity in PC3 cells, reducing the IC50 of paclitaxel by >90%. These findings illustrate that combined suppression of antiapoptotic Bcl-2 family members using this antisense oligonucleotide could be an attractive strategy for inhibiting cancer progression through alteration of the apoptotic rheostat in androgen-independent prostate cancer.
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PMID:A novel antisense oligonucleotide inhibiting several antiapoptotic Bcl-2 family members induces apoptosis and enhances chemosensitivity in androgen-independent human prostate cancer PC3 cells. 1627 90


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