Study on mechanism of apoptosis induced by Ara-C in leukemia HL-60 cells

Objective:To explore the machanism of apoptosis induced by Ara-C in HL-60 cells.Methods:Cell viability was determined by trypan blue exclusion,the growth inhibition was analyzed by MTT assay;cell apoptosis by morphology and flow cytometry;Bcl-2 and caspase-3 by western blot.Results:Ara-C(1-100μM)inhibited cellular proliferation and induced apoptosis and reducde the levels of Bcl-2 proteins and activated caspase-3 in a dose and time dependent fashion in HL-60 cells.PD98059(25μM)(a inhibitor of MEK)enhanced apoptosis and activity of caspase-3 induced by Ara-C without altering Bcl-2 protein.However,SB203580(20μM)(a inhibitor of P38MAPK)reduced the apoptosis and activity of caspase-3 induced by Ara-C without altering Bcl-2 protein.SP600125(a inhibitor of JNK)did not affected effects of Ara-C.Conclusion:Ara-C downregulates Bcl-2 and activates caspase-3 during apoptosis in HL-60 cells;a inhibitor of MEK enhances apoptosis induced by Ara-C.However,a inhibitor of P38MAPK reduces the effects of Ara-C in HL-60 cells.