EFFECT OF NIMODIPINE ON Caspase SIGNAL PATHWAY OF HL-60 CELL APOPTOSIS INDUCED BY CYTARABINE

Objective To study the effect of nimodipine on the mechanism of HL-60 cell apoptosis induced by cytarabine(Ara-c). MethodsThe log phase HL-60 cells were collected,and divided into control group(no any drugs were aided),nimodipine group(0.001-0.100 g/L),Ara-c group(0.005-0.500 g/L) and nimodipine +Ara-c group.The cells in each group were treated for 24 h.ATP chemiluminometry was employed to detect the cell cytostasis and Caspase 8 activity in each group,and AO/EB fluorescent staining to observe the cell apoptosis. ResultsCompared with the control group,the differences of cell proliferation inhibition(PI) rate of HL-60 in different-concentration nimodepine or Ara-c groups were significant(F=12 231.563,6 404.210;P0.01).When the concentration of nimodepine was 0.050 g/L and that of Ara-c was 0.010 g/L,the PI rate being the highest(F=916.836,P0.01).When the concentration of Ara-c was 0.010 g/L,and that of nimodepine was 0.050 g/L,the cell apoptosis rate in both Ara-c and NMDP+Ara-c groups was dramatically higher that that in the control group and nimodepine group,the apoptosis being the highest in NMDP+Ara-c group(F=148.02,P0.01).Compared with the control and nimodipine,the activity of Caspase 8 in Ara-c group and NMDP+Ara-c group was enhanced,of which,the highest was seen in NMDP+Ara-c group(F=732.84,P0.01). ConclusionNimodipine can strengthen HL-60 cell apoptosis induced by Ara-c,the mechanism is probably associated with enhancement of Caspase 8 activity.