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)

Up-regulation of Bcl-2 protein may contribute to drug resistance, by decreasing apoptosis after treatment, in pre-B and B-cell leukemias in pediatric patients. By contrast, augmented caspase-3 activity, an effector caspase, may be indicative of drug sensitivity due to increased cellular apoptosis. We have reported the development of an in vitro human T-lymphoblastic leukemia model resistant to ara-C and/or native E. coli L-asparaginase (ASNase), mimicking the drug resistance to the Capizzi II regimen. We have investigated the potential drug synergism between Idarubicin (IDA) and Taxotere (TXR) that may be active in the ara-C and ASNase double drug-resistant cell lines. The additive or synergistic activity between IDA and TXR is drug concentration-dependent in inducing caspase-3 activation and cellular apoptosis. We exposed two human drug-resistant cell lines that do not express the MDRI phenotype, one resistant to ASNase alone (CEM/ASNase-1-3) and the other resistant to both ara-C and ASNase (CEM/ara-C/I/ASNase-0.5-2), to physiologically achievable concentrations of IDA, TXR, or their combination. Both lines showed either synergistic drug activity to the combination regimen in comparison to either drug used alone, as determined by MTT assay, or additivity as demonstrated by flow cytometry after Annexin V and propidium iodide (PI) staining. After exposure of the ASNase-resistant line to various concentrations, the intracellular levels of Bcl-2 protein decreased to near zero relative to untreated control cells. The Bcl-2 protein reductions in these cells ranged from 30% to <1%, 49% to <1%, and 27% to 3% when treated with IDA or TXR as a single drug or IDA + TXR combination, respectively. Similarly, intracellular Bcl-2 levels in the double-resistant cell line decreased with reductions ranging from 24% to <1%, 87% to <1%, and 46% to <1% of the untreated control after treatment with IDA, TXR, or their combination, respectively. Conversely, the caspase-3 activity increased in a dose-dependent manner and inversely-correlated with loss of cell viability (r= 0.91) after exposure to IDA + TXR combination in the double drug-resistant line to both ara-C and ASNase. We conclude that the combination of the IDA + TXR regimen is highly synergistic or additive in drug resistant human leukemic cell clones. The molecular mechanism of action is due to the down-regulation of Bcl-2 protein and up-regulation of caspase-3 activity. This drug combination warrants further investigation for use in the treatment of patients with ara-C and/or ASNase refractory leukemias.
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PMID:The combination regimen of idarubicin and taxotere is effective against human drug-resistant leukemic cell lines. 1216 12

Idarubicin (IDA) is a 4-demethoxy-anthracycline analogue of daunorubicin (DNR). IDA has been recognized as a potent anti-leukemic agent. However, the molecular mechanism of IDA-induced cell death remains unclear. In the present study, we investigated the activity of IDA to induce apoptosis in human leukemia HL-60 and Jurkat cells, and studied its relationship with activation of caspases-3/7. IDA induced apoptotic DNA fragmentation in a time- and dose-dependent manner. The kinetics of apoptotic DNA fragmentation induced by IDA was well correlated with that of caspase-3/7 activation. We examined the effect of caspase-3/7 inhibitor Ac-DEVD-CHO on IDA-induced apoptosis in HL-60 and Jurkat cells. Ac-DEVD-CHO abolished IDA-induced caspases-3/7 activation in both cell lines. We have also found that L-carnitine can inhibit recombinant caspase-3 activity in vitro. L-carnitine treatment prevented IDA-induced caspases-3/7 activation in both cell lines in a dose-dependent manner. However, neither Ac-DEVD-CHO nor L-carnitine inhibited IDA-induced apoptotic internucleosomal DNA fragmentation in HL-60 or Jurkat cells. These data suggest that caspase-3/7 may be dispensable for idarubicin-induced internucleosomal DNA cleavage during apoptosis in human leukemia cells.
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PMID:Activation of caspases-3/7 is dispensable for idarubicin-induced apoptotic DNA fragmentation in human leukemia cells. 1268 80

The caspase family of protease is speculated to have a crucial role in apoptosis. The effect of treatment with Idarubicin (IDA) and Medroxyprogesterone acetate (MPA), used alone or in combination, on the activation of Caspase-3 in canine Chronic Lymphatic Leukaemia (CLL) cells was investigated, in order to clarify the mechanism of chemo- and hormone-therapy mediated apoptosis. Caspase activity was determined by a quantitative fluorimetric assay. Apoptosis was monitored by propidium iodide (PI) and nucleosomes assay. Treatment of CLL cells for 24 h with MPA 5 microM did not significantly activate caspase-3 but its activity was increased almost 5-fold more with IDA 1 microM (P < 0.05) than control. Treatment of CLL cells with IDA 1 microM in equimolecular association with MPA was able to increase the activation of caspase-3 induced by IDA of the 61.2% (P < 0.05) in comparison with IDA alone. The activation of caspase-3 was confirmed evaluating apoptosis by PI and nucleosomes assay. Furthermore, both caspase-3 activation and apoptosis triggered by IDA alone or in combination with MPA were significantly inhibited by specific caspase-3 inhibitor AC-DEVD-CMK. These findings provide an explanation for IDA and MPA induced-apoptosis mechanism.
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PMID:MPA increases idarubicin-induced apoptosis in chronic lymphatic leukaemia cells via caspase-3. 1285 40