Caspases promoted DADAG-induced apoptosis in human leukemia HL-60 cells.

AIM: To investigate the roles of caspases in diacetyldianhydrogalactitol
(DADAG)-induced apoptosis in human leukemia HL-60 cells.
METHODS: Inhibition of proliferation was measured by MTT assay. DADAG-induced
apoptosis in HL-60 cells was observed by electron microscopy, flow cytometry, and
DNA fragmentation assay. Caspase-3 activity was determined by ApoAlert CPP32
colorimetric assay kit. The cleavage of substrates of caspases was detected by
Western blot.
RESULTS: DADAG exhibited potent antiproliferative activity and induced apoptosis
in HL-60 cells. After treatment with DADAG 8 mg/L for 24 h, caspase-3 activity
increased markedly and the cleavage of poly-(ADP-ribose) polymerase (PARP), lamin
B, and DFF45 appeared. All of the apoptotic signals were suppressed by z-VAD fmk
(a general inhibitor of caspase activities), whereas z-DEVD fmk, a selective
inhibitor of caspase-3 activity, only induced partial reversion of the apoptotic
effects.
CONCLUSION: DADAG induced apoptosis in HL-60 cells by activating caspases.
Caspases promoted apoptosis through the cleavage of substrates of PARP, lamin B,
and DFF45.