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[The mechanism of apoptosis induced by anticancer agents in human leukemia cells]
Abstract:
Many anticancer agents induce apoptosis in human leukemia cells. Among the various leukemia cells, especially HL-60 cells and U937 cells are very sensitive to apoptosis upon anticancer agents treatment. A serine protease inhibitor TPCK and an ICE-like protease inhibitor VAD-FMK prevented etoposide, camptothecin and ara-C-induced internucleosomal DNA cleavage in human myeloid leukemia HL-60 and U937 cells. Using a cell-free system, we have examined the inhibitory mechanism of these inhibitors on anticancer agent-induced internucleosomal DNA cleavage. Our data indicate that serine and ICE-like proteases may be involved in anticancer agent-induced apoptosis at the different stages, and especially a serine protease may be closely associated with the final step for induction of DNA fragmentation during apoptosis in human myeloid leukemia HL-60 and U937 cells.
Insights
Anticancer drugs trigger apoptosis in leukemia cells like HL-60 and U937. Protease inhibitors suggest serine proteases are key in DNA fragmentation during this programmed cell death.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Context:
- Anticancer agents are known to induce apoptosis (programmed cell death) in human leukemia cells.
- HL-60 and U937 cell lines are particularly sensitive to apoptosis induction by various chemotherapeutic drugs.
- Internucleosomal DNA cleavage is a hallmark of apoptosis.
Purpose:
- To investigate the role of proteases in anticancer agent-induced apoptosis in human myeloid leukemia cells.
- To elucidate the mechanism by which serine protease inhibitors and ICE-like protease inhibitors affect DNA fragmentation.
Summary:
- Treatment of HL-60 and U937 cells with etoposide, camptothecin, and ara-C induced internucleosomal DNA cleavage, a key event in apoptosis.
- TPCK (a serine protease inhibitor) and VAD-FMK (an ICE-like protease inhibitor) significantly prevented this DNA cleavage.
- Experiments in a cell-free system confirmed the inhibitory effects of these proteases on DNA fragmentation.
Impact:
- Serine and ICE-like proteases are implicated in different stages of anticancer agent-induced apoptosis.
- A serine protease appears to be critically involved in the final DNA fragmentation step of apoptosis in these leukemia cell lines.
- This research provides insights into the molecular mechanisms underlying chemotherapy-induced apoptosis, potentially aiding in the development of targeted therapies.