The difference in inducing apoptosis of leukemic cell lines by recombinant human soluble TNF-related apoptosis inducing ligand(rhsTRAIL)

To compare the difference in inducing apoptosis of leukemic cell lines Jurkat cells,K562 cells and HL-60 cells by recombinant human soluble TNF-related apoptosis inducing ligand(rhsTRAIL) and to explore the relationship between these differences and the expression quantity of the TRAIL receptors,such as DR4,DR5,DcR1 and DcR2,the leukemic cell lines employed were treated with different concentrations of rhsTRAIL for 12,24,and 48 hours respectively.The apoptosis was detected by PI staining and flow cytometry,and the expressions of the TRAIL receptors DR4,DR5,DcR1 and DcR2 were detected by RT-PCR.It was demonstrated that the apoptosis rate of Jurkat cells induced with different concentrations was higher than that of the untreated cells in a dose-and time-dependent manner.However,no significant evidence of apoptosis was found in case of the K562 and HL-60 cells line.As demonstrated by RT-PCR,the expression of DR4 on the surface of the Jurkat cells line was increased along with the prolongation of cultivation times for cells and the increasing concentrations of rhsTRAIL,but no expression of DR5,DcR1 and DcR2 could be detected.On the surface of the K562 cells and HL-60 cells,the expression of DR4 showed no significant change,and no expression of DR5,DcR1 and DcR2 could be detected also.The apoptosis of Jurkat cells induced by rhsTRAIL had dose-and time-dependence and showed positive correlation with the surface expression of DR4.It is evident that under certain concentration of rhsTRAIL induces no apoptosis of the K562 cells and HL-60 cells and no significant change on the surface expression of DR4 can be found.These results suggest that in case of treatment of patients with leukemia with TRAIL,its dosage and range of application should be carefully appreciated.