[Mechanism of apoptosis induced by squamocin in leukemia cells].

ABSTRACT

AIM: To investigate the mechanism of apoptosis of HL60 cells induced by the annonaceous acetogenin, squamocin. METHODS: Induction of apoptosis was determined through Hoechst33258 dye staining and DNA agarose gel electrophoresis. Expression of the proteins was detected using Western blot analysis. Caspase-3 activity was detected using caspase-3 kit. RESULTS: Treatment of HL-60 cells with squamocin resulted in extensive nuclear condensation, DNA fragmentation, cleavage of the death substrate poly(ADP-ribose) polymerase (PARP) and induction of caspase-3 activity. Pretreatment of HL-60 cells with caspase-3 specific inhibitor DEVD-CHO prevented squamocin-induced DNA fragmentation, PARP cleavage and cell death. Stress-activated protein kinase (SAPK/JNK) was activated after treatment with squamocin in HL-60 cells. CONCLUSION: These results suggest that apoptosis of HL-60 cells induced by squamocin require caspase-3 activation, and could be related to SAPK activation.