STI571诱导K562细胞凋亡机制研究

The mechanism of STI571 inducing apoptosis of K562 cells

目的 研究格列卫 (Glivec ,STI5 71)诱导P2 10BCR/ABL(+)K5 6 2细胞凋亡机制。方法 采用Annexin Ⅴ /PI双染实验、DNA的PI染色、碘化二己基恶碳菁 (DiOC6 [3])染色、2 ,7 二氯荧光素二乙酸酯 (DCFH DA)染色及DNALadder等方法测定凋亡细胞。利用Westernblot实验分析K5 6 2细胞蛋白酪氨酸磷酸化水平 ,测定Bcl XL、caspase 3蛋白的表达并分别测定线粒体及胞浆部分的细胞色素C(cytoC)蛋白。结果 STI5 71可诱导K5 6 2细胞凋亡 ,出现DNA亚二倍体凋亡峰及DNALadder,线粒体跨膜电位及活性氧物质降低 ,P2 10BCR/ABL酪氨酸磷酸化水平降低 ,Bcl XL、蛋白减少 ,caspase 3蛋白前体活化降解出相对分子质量为 2 0× 10 3 亚单位 ,胞浆部分出现cytoC ,同时线粒体cytoC减少。结论 STI5 71可迅速使P2 10BCR/ABL酪氨酸磷酸化水平下降 ,线粒体cytoC胞浆转位介导的信号通路是STI5 71诱导K5 6 2细胞凋亡的途径之一 ,STI5

Objective To investigate the mechanism of STI571 inducing apoptosis of K562 cells which express P210 BCR/ABL . Methods Apoptosis was analyzed by Annexin V/PI, DioC6 staining, DCFH DA staining, DNA PI staining and DNA ladder. Western blot was used to analyse mitochondrial and cytosolic cyto C, Bcl X L,caspase 3, actin protein and the level of tyrosine phosphorylation. Results After exposure to STI571, K562 cells were induced to apoptosis. Tyrosine phosphorylation level of P210 BCR/ABL and Bcl X L was decreased. Caspase 3 was activated and there was an cytosolic accumulation of cyto C. Conclusion STI571 could rapidly decrease the tyrosine phosphorylation level of P210 BCR/ABL . The signal pathway mediated by the cytosolic translocation of mitochondrial cyto C was one of the mechanisms that STI571 inducing apoptosis. STI571 was an effective gene targeting therapeutic agent.