[Effects of diallyl disulfide on apoptosis of human leukemia K562 cells and expression of Fas, FasL and caspase-8].

OBJECTIVE: To study the effects of diallyl disulfide (DADS) on apoptosis of human leukemia K562 cells and possible mechanisms. METHODS: The morphologic changes of leukemia K562 cells after DADS treatment were observed by Hoechst 33258 staining. Cell apoptosis rates after different concentrations and different durations of DADS treatment were determined by flow cytometry. Fas, FasL and caspase-8 mRNA expression was estimated by reverse transcription-polymerase chain reaction (RT-PCR) 48 hrs after DADS treatment. RESULTS: The characteristics of apoptosis in K562 cells induced by DADS were observed. After 24 hrs of DADS treatment, the apoptosis rate of K562 cells increased from (11.60 ± 0.83)% at the concentration of 10 mg/L to (37.94 ± 0.87)% at the concentration of 40 mg/L. The apoptosis rate of K562 cells increased after 40 mg/L DADS with the increasing time from (37.94 ± 0.87)% (24 hrs) to (47.02 ± 0.66)% (72 hrs). Expression of Fas and caspase-8 mRNA increased, while FasL mRNA expression decreased significantly 48 hrs after DADS treatment compared with the control group (P<0.05). CONCLUSIONS: DADS can induce apoptosis of human leukemia K562 cells in a time- and concentration-dependent manner, possibly through increasing Fas and caspase-8 expression and decreasing FasL expression.