Apoptosis of K562 cells induced by a new immunosuppressive agent FTY720 and its mechanism / 吉林大学学报(医学版)

ABSTRACT

Objective To study the apoptosis of K562 cells induced by a new immunosuppressive agent FTY720 and its mechanism,and to provide experimental basis for the treatment of leukemia in clinic.Methods The K562 cells were cultured in vitro and divided into blank control group and FTY720 treatment group.The K562 cells in FTY720 treatment group were treated with 6μmol·L-1 FTY720 for 3,6,and 12 h,or treated with different concentrations of FTY720 (2,4,6,8μmol·L-1)for 24 h.The apoptosis,level of reactive oxygen species (ROS),mitochondrial membrane potential(MMP)and cell cycle were measured by flow cytometry.The inhibitory rate of proliferation of K562 cells after treated with FTY720 was detected by WST-1 reducting assay.Results The results of flow cytometry showed that the percentages of apoptotic cells were increased after treated with 6μmol·L-1 FTY720 for 3,6,and 12 h with the prolongation of time compared with blank control group(P<0.01).The percentages of apoptotic cells were also increased after treated with different concentrations of FTY720 for 24 h compared with blank control group(P<0.01).Compared with blank control group,the ROS levels were increased with the increasing of FTY720 concentration,while the MMP was decreased(P<0.01).Compared with blank control group,the percentage of cells at G0/G1 phase was increased,while those at S and G2/M phases were decreased with the increasing of FTY720 concentration (P<0.05).The WST-1 reduction assay results indicated that the inhibitory rates of proliferation of K562 cells after treated with 2,4,6,and 8μmol·L-1 FTY720 for 72 h were (24.0±4.1)%,(46.4±3.9)%,(67.0±4.8)%,and (88.2±5.6)%,respectively,compared with blank control group.The concentration of FTY720 to result the inhibitory rate of 50% (IC50 )on K562 cells was 5.5μmol·L-1 .Conclusion FTY720 could inhibit the proliferation of K562 cells by blocking cell cycle and inducing apoptosis through provoking ROS.