藤黄酸调控白血病K562细胞GFI-1表达及对细胞增殖和凋亡的影响

Gambogic acid regulates GFI-1 expression in K562 cells and its effects on cell proliferation and apoptosis

目的:探讨藤黄酸对白血病K562细胞增殖和凋亡的影响及可能的机制。方法:体外培养K562细胞,采用CCK-8法检测不同浓度藤黄酸(0、0.2、0.4、0.8、1.2、2.0μmol/L)处理24、48、72 h后K562细胞增殖率;用流式细胞术检测K562细胞的凋亡和周期;采用实时荧光定量聚合酶链反应(RT-qPCR)和Western blot法检测独立生长因子1(GFI-1)的mRNA及蛋白表达水平。结果:藤黄酸可以抑制K562细胞的增殖,并呈剂量、时间依赖性;0.4μmol/L藤黄酸处理24 h后的K562细胞凋亡率增加;藤黄酸对GFI-1的mRNA表达无显著影响,藤黄酸可以下调GFI-1蛋白的表达;藤黄酸及蛋白酶体抑制剂(MG132)共处理后的K562细胞GFI-1蛋白水平较藤黄酸组升高;藤黄酸及氯喹(CQ)共处理后的K562细胞GFI-1蛋白水平与藤黄酸组无统计学差异(P>0.05)。结论:藤黄酸可以有效抑制K562细胞的增殖并诱导细胞凋亡;藤黄酸可以诱导K562细胞G0/G1期及S期阻滞;藤黄酸通过蛋白酶体途径促进GFI-1蛋白降解。

Objective:To investigate the effect of gambogic acid on proliferation and apoptosis of leukemic K562 cells and its possible mechanism.Methods:K562 cells were cultured in vitro,and the proliferation rate of K562 cells after treatment with different concentrations of gambogic acid(0,0.2,0.4,0.8,1.2,2.0μmol/L)for 24,48,and 72 h was determined by CCK-8 method.Flow cytometry was used to detect the apoptosis and cycle death of K562 cells.K562 cells were treated by different methods,and mRNA and protein expression levels of independent growth factor 1(GFI-1)were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)and Western blotting respectively.Results The proliferation of K562 cells was inhibited by gambogic acid in a dose-dependent and time-dependent manner.After treatment with 0.4μmol/L gambogic acid for 24 h,the apoptosis rate of K562 cells increased.The GFI-1 mRNA expression was not significantly affected by gambogic acid,but the GFI-1 protein expression was down-regulated by gambogic acid.GFI-1 protein level in K562 cells treated with gambogic acid+proteasome inhibitor was increased as compared with that in the gambogic acid group,and GFI-1 protein level in K562 cells treated with gambogic acid+chloroquine showed no significantly different from that in the gambogic acid group.Conclusion:Gambogic acid can effectively inhibit the proliferation of K562 cells and induce cell apoptosis;Gambogic acid can induce arrest of K562 cells at G0/G1 phase and S phase;Gambogic acid promotes the degradation of GFI-1 protein by the proteasome pathway.