Caspases家族成员促进DADAG诱导的人白血病HL—60细胞凋亡

目的:研究caspases家族成员在二乙酰二脱水卫矛醇(DADAG)诱导人白血病HL-60细胞凋亡中的作用.方法:MTT法观察DADAG的体外抗增殖作用;透射电镜、DNA梯形条带和流式细胞仪检测HL-60细胞凋亡;caspase-3检测试剂盒和Western blot法分析caspases家族成员.结果:DADAG明显抑制HL-60细胞增殖和诱导细胞凋亡.DADAG处理HL-60细胞24h后,caspase-3酶活性达峰值,同时聚腺苷二磷酸核糖聚合酶(PARP)、lamin B和DFF45蛋白开始出现断裂片段.Caspase-3抑制剂z-DEVD·fmk可部分逆转DADAG诱导的HL-60细胞凋亡,而caspases广谱抑制剂z-VAD·fmk可完全逆转此作用.结论:Caspases在DADAG诱导HL-60细胞凋亡中起重要作用,它们通过酶解底物PARP、DFF45和lamin B促进细胞凋亡.

Caspases promoted DADAG-induced apoptosis in human leukemia HL-60 cells

AIM: To investigate the roles of caspases in diacetyldianhydrogalactitol (DADAG)-induced apoptosis in human leukemia HL-60 cells. METHODS: Inhibition of proliferation was measured by MTT assay. DADAG-induced apoptosis in HL-60 cells was observed by electron microscopy, flow cytometry, and DNA fragmentation assay. Caspase-3 activity was determined by ApoAlert CPP32 colorimetric assay kit. The cleavage of substrates of caspases was detected by Western blot. RESULTS: DADAG exhibited potent antiproliferative activity and induced apoptosis in HL-60 cells. After treatment with DADAG 8 mg/L for 24 h, caspase-3 activity increased markedly and the cleavage of poly-(ADP-ribose) polymerase (PARP), lamin B, and DFF45 appeared. All of the apoptotic signals were suppressed by z-VAD fmk (a general inhibitor of caspase activities), whereas z-DEVD fmk, a selective inhibitor of caspase-3 activity, only induced partial reversion of the apoptotic effects. CONCLUSION: DADAG induced apoptosis in HL-60 cells by activating caspases. Caspases promoted apoptosis through the cleavage of substrates of PARP, lamin B, and DFF45.