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)

Bisphosphonate (BP), a specific inhibitor of osteoclasts, has been widely used as a beneficial agent for the treatment of bone metastases in patients with breast cancer. It is well recognized that BP reduces osteolysis by promoting apoptosis in osteoclasts. However, recent animal and human data suggest that BPs not only reduce osteolysis associated with metastatic breast cancer, but also decrease tumor burden in bone. The mechanisms by which tumor burden is decreased following BP administration are unknown. Here we examined the effects of the BP ibandronate on MDA-231 human breast cancer cells in bone metastases in a well-characterized animal model of bone metastasis. Ibandronate, which was administered (s.c. daily; 4 microg/mouse/day) after bone metastases were established, inhibited the progression of established osteolytic bone metastases as assessed by radiographic analysis. Histological and histomorphometrical examination revealed that ibandronate reduced osteoclastic bone resorption, with increased apoptosis in osteoclasts. Furthermore, ibandronate also significantly decreased the MDA-231 tumor burden, with increased apoptosis in MDA-231 breast cancer cells in bone metastases. In contrast, ibandronate failed to inhibit MDA-231 tumor formation with no effects on apoptosis in MDA-231 breast cancer cells in the orthotopic mammary fat pads. These data suggest that the effects of ibandronate on apoptosis in MDA-231 breast cancer cells are restricted in bone in which ibandronate selectively deposits. Consistent with these in vivo results, a relatively high concentration of ibandronate (100 microM) increased caspase-3 activity and induced DNA fragmentation in MDA-231 breast cancer cells in culture. Moreover, a caspase inhibitor, z-Val-Ala-Asp-fluoromethyl ketone, blocked ibandronate-induced DNA fragmentation in MDA-231 cells, suggesting an involvement of caspase-3 in ibandronate-induced apoptosis. Our results suggest that BP suppresses bone metastases through promotion of apoptosis in metastatic cancer cells as well as in osteoclasts. However, it still remains open whether BP has direct anticancer actions in vivo.
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PMID:The bisphosphonate ibandronate promotes apoptosis in MDA-MB-231 human breast cancer cells in bone metastases. 1138 70

Over 80% of patients with advanced breast and prostate cancer ultimately develop bone metastases. Ibandronic acid has proven efficacy for treatment of bone metastasis secondary to breast cancer. This study was designed to investigate the cytotoxic and apoptotic effects of ibandronic acid on hormone- and drug-refractory prostate carcinoma DU-145 and human breast cancer MCF-7 cell lines. Cytotoxicity was evaluated using an XTT cell proliferation kit, and apoptosis was assessed by enzyme-linked immunosorbent assay (histone-DNA fragmentation) and measurement of caspase 3/7 activity. With increasing concentrations of ibandronic acid there was a dose- and time-dependent decrease in cell numbers. MCF-7 cells were more resistant than DU-145 cells (half maximal inhibitory concentrations of 122 and 90 microM, respectively). Ibandronic acid induced apoptosis in both cell lines. The study showed an apoptosis-mediated cytotoxic effect for ibandronic acid (in addition to the already known osteoclast inhibiting effect) in breast cancer patients with bone metastases; which was also observed in prostate cancer cells. Further clinical studies involving breast and prostate cancer patients with bone metastases are warranted to confirm these findings.
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PMID:Apoptosis-mediated cytotoxic effects of ibandronic acid on hormone- and drug-refractory prostate cancer cells and human breast cancer cells. 2130 80