The mechanism of HL-60 cell apoptosis induced by anti-human DR5 monoclonal antibody

To study the mechanism of HL-60 cell apoptosis induced by anti-human DR5 monoclonal antibody,HL-60 cells were treated with mDRA-6 or / and Caspase inhibitors,and the inhibition ratio was determined using MTT assay.The DNA ladder of HL-60 cells treated with mDRA-6(lOmg/L) for 6 h was analyzed by 1%agrose gel electrophoresis.The expression of Caspase 8,Caspase 10 and Caspase 3 of HL-60 cells after treating with mDRA-6 were detected by Western blotting,respectively. It was demonstrated that the proliferation of HL-60 cell after treating with mDRA-6 was inhibited in a dose-dependent and time-dependent manner,the inhibition ratio of HL-60 cells treated by 10 jig/ml mDRA-6 for 6 h,8 h and 10 h were 23. 96%44.10%and 50.28%,respectively.DNA fragmentation detection indicated that HL-60 cell apoptosis was induced by mDRA-6.Western blotting revealed that Caspase 10 and Caspase 3 in HL-60 cells treated with mDRA-6 were activated in a time-dependent manner,but Caspase 8 did not.The HL-60 cells were incubated with the inhibitors for Caspase 8,10 and 3 for 1 hour,respectively,and then the cells were treated with mDRA-6,HL-60 cell apoptosis induced by mDRA-6 were reduced by 4.40%(t = 0.52,P0.05),64.15%(r= 10.13,P0.01) and 53.69(r=8.93,P0.01)%,respectively.Therefore,it is evident that Caspase 10 inhibits apoptosis of HL-60 cells pretreated with anti-human DR5 monoclonal antibody mDRA-6.