Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.60 (caspase-7)
 920 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glioblastoma multiforme (GBM) is a highly aggressive brain cancer that is characterized by the paradoxical features of intense apoptosis resistance yet a marked propensity to undergo necrosis. Bcl2L12 (for Bcl2-Like12) is a nuclear and cytoplasmic oncoprotein that is universally overexpressed in primary GBM and functions to block postmitochondrial apoptosis signaling by neutralizing effector caspase-3 and caspase-7 maturation. This postmitochondrial block in apoptosis engenders the alternate cell fate of cellular necrosis, thus providing a molecular explanation for GBM's classical features. Whereas Bcl2L12-mediated neutralization of caspase-7 maturation involves physical interaction, the mechanism governing Bcl2L12-mediated inhibition of caspase-3 activity is not known. The nuclear localization of Bcl2L12 prompted expression profile studies of primary astrocytes engineered to overexpress Bcl2L12. The Bcl2L12 transcriptome revealed a striking induction of the small heat shock protein alpha-basic-crystallin (alphaB-crystallin/HspB5), a link reinforced by robust alphaB-crystallin expression in Bcl2L12-expressing orthotopic glioma and strong coexpression of alphaB-crystallin and Bcl2L12 proteins in human primary GBMs. On the functional level, enforced alphaB-crystallin or Bcl2L12 expression enhances orthotopic tumor growth. Conversely, RNAi-mediated knockdown of alphaB-crystallin in Bcl2L12-expressing astrocytes and glioma cell lines with high endogenous alphaB-crystallin showed enhanced apoptosis, yet decreased necrotic cell death with associated increased caspase-3 but not caspase-7 activation. Mirroring this specific effect on effector caspase-3 activation, alphaB-crystallin selectively binds pro-caspase-3 and its cleavage intermediates in vitro and in vivo. Thus, alphaB-crystallin is a Bcl2L12-induced oncoprotein that enables Bcl2L12 to block the activation of both effector caspases via distinct mechanisms, thereby contributing to GBM pathogenesis and its hallmark biological properties.
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PMID:Bcl2L12-mediated inhibition of effector caspase-3 and caspase-7 via distinct mechanisms in glioblastoma. 1866 46

Brazilin, isolated from the methanol extract of the heart wood of Caesalpinia sappan, sensitizes cancer cells to apoptosis. Glioblastoma multiforme (GBM), which accounts for most cases of central nervous system malignancy, has a very poor prognosis and lacks effective therapeutic interventions. We, therefore, investigated the effects of different concentrations of and different periods of exposure to brazilin on cell proliferation and apoptosis in the glioma U87 cell line. Cell proliferation was investigated by MTT assays and growth curve analysis, apoptosis was assessed by FACS analysis and western blot studies. Brazilin showed dose-dependent inhibition of cell proliferation and induction of apoptosis in glioma cells. It also increased the ratio of cleaved poly-(ADP)-ribose polymerase and decreased the expression of caspase-3 and caspase-7.
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PMID:Brazilin inhibits growth and induces apoptosis in human glioblastoma cells. 2342 18

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells. TRAIL resistance in cancers is associated with aberrant expression of the key components of the apoptotic program. However, how these components are regulated at the epigenetic level is not understood. In this study, we investigated novel epigenetic mechanisms regulating TRAIL response in glioblastoma multiforme (GBM) cells by a short-hairpin RNA loss-of-function screen. We interrogated 48 genes in DNA and histone modification pathways and identified KDM2B, an H3K36-specific demethylase, as a novel regulator of TRAIL response. Accordingly, silencing of KDM2B significantly enhanced TRAIL sensitivity, the activation of caspase-8, -3 and -7 and PARP cleavage. KDM2B knockdown also accelerated the apoptosis, as revealed by live-cell imaging experiments. To decipher the downstream molecular pathways regulated by KDM2B, levels of apoptosis-related genes were examined by RNA-sequencing upon KDM2B loss, which revealed derepression of proapoptotic genes Harakiri (HRK), caspase-7 and death receptor 4 (DR4) and repression of antiapoptotic genes. The apoptosis phenotype was partly dependent on HRK upregulation, as HRK knockdown significantly abrogated the sensitization. KDM2B-silenced tumors exhibited slower growth in vivo. Taken together, our findings suggest a novel mechanism, where the key apoptosis components are under epigenetic control of KDM2B in GBM cells.
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PMID:KDM2B, an H3K36-specific demethylase, regulates apoptotic response of GBM cells to TRAIL. 2866 78

Glioblastoma multiforme (GBM) is a central nervous system tumor of grade IV, according to the WHO classification, extremely resistant to all currently used forms of therapy, including resection, radiotherapy, chemotherapy or combined therapy. Therefore, more effective treatment strategies of this tumor are needed, with boron neutron capture therapy (BNCT) being a potential solution, provided a proper cancer cells-targeted 10B delivery agent is found. In search of such an agent, toxicity and capacity to target DNA of a boronated derivative of 2'-deoxycytidine, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine (1), was tested against human tumor vs. normal cells. The present in vitro results revealed 1 to show low toxicity for human U-118 MG glioma cells (in the mM range) and even by 3-4 - fold lower against normal human fibroblasts. In accord, induction of apoptosis dependent on caspase-3 and caspase-7 was detected at high (>20mM) concentration of 1. Although demonstrated to be susceptible to phosphorylation by human deoxycytidine kinase and to undergo incorporation in cellular DNA, the boron analogue did not disturb cell proliferation when applied at non-toxic concentrations and showed low toxicity to a model metazoan organism, Caenorhabditis elegans. Thus, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine appears a promising candidate for a 10B delivery agent to be used in BNCT, with C. elegans indicated as a good model for in vivo studies.
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PMID:N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine as a potential boron delivery agent with respect to glioblastoma. 2888 21