活化Chk1引起的G_2/M期阻滞在调节K562/A02细胞耐药中的机制探讨  

Mechanism of G_2/M Blockage Triggered by Activated-Chk1 in Regulation of Drug-resistance in K562/A02 Cell Line

作　　者：王海燕[1] 张敏[2] 邹萍[2] 游泳[2] 郭静明[1] 唐晓琼[2] 赵智刚[2] 吴耀辉[2] 

机构地区：[1]三峡大学第一临床医学院,宜昌市中心人民医院血液科,宜昌443003 [2]华中科技大学同济医学院附属协和医院血液科,武汉430022

出　　处：《中国实验血液学杂志》2006年第6期1105-1109,共5页Journal of Experimental Hematology

摘　　要：本研究探讨活化的Chk1对白血病细胞周期及凋亡的影响,探究Chk1调控肿瘤细胞耐药的机制。以慢性粒细胞白血病细胞系K562及其耐药细胞系K562/A02(耐阿霉素)为研究对象,与阿霉素共孵育后,用流式细胞术检测细胞周期分布,RT-PCR检测Chk1mRNA表达水平,Westernblot检测转染前后Chk1磷酸化水平;靶向Chk1shRNA抑制细胞内Chk1的表达后,用流式细胞术检测阿霉素作用后细胞的凋亡情况。结果表明阿霉素致K562/A02细胞阻滞在G2/M期的细胞百分率为(54.12±0.57)%,显著高于K562细胞(36.99±1.28)%;Chk1mRNA表达水平在K562与K562/A02细胞间无显著差异;Chk1磷酸化水平在K562/A02细胞为0.79±0·56,在K562细胞为0.27±1·47,其差异有统计学意义。转染Chk1shRNA后,两株细胞的Chk1磷酸化水平显著下降。转染组K562、K562/A02细胞凋亡率分别是空载体转染组的1.30倍和3.84倍。结论Chk1的活化水平调控着K562/A02细胞对阿霉素的敏感性。The study was purposed to investigate the effect of phosphorylated-chk1 on cell cycle and apoptosis of human erythroleukemic cell line K562 and K562/A02, and to explore the mechanism of chk1 in regulation of drug-resistance of leukemia cells. After treatment with adrimycin for six hours, the cell cycle distribution was detected by flow cytometry; the Chk1 mRNA expression was detected by RT-PCR and the Chk1 phosphorylation level was detected by Western blot. Under the condition of down-regulation of Chk1mRNA expression in cells transfected with Chk1 short hairpin RNA, the cell apoptosis rates were detected by flow-cytometry following adrimycin. The results indicated that the pro- portion of K562/A02 cell line in Ga/M phase was （54.12 ± 0.57 ）% at 6 hours after drug treatment, significantly higher than that of K562 cell line （ 36.99 ± 1.28 ） %. No evident difference of the Chk1 mRNA expression was observed between K562 and K562/A02 cell lines, while elevated Chk1 phosphorylation following DNA damage induced by adriamycin was observed in the K562/A02 cell line （0.79 ± 0.56）, significantly higher than that in K562 cell line （0.27 ± 1.47）. The cell apoptosis rate of the Chk1 shRNA group in K562/A02 cell line was 3.84-fold of blank vector group, but that in K562 cell line was 1.30-fold of blank vector group. It is concluded that the increased chk1 activity that delay the progress of cell cycle are associated with cellular resistance to adrimycin in the K562/A02 cell line .

关 键 词：CHK1 G2/M期阻滞 K562细胞 K562/A02细胞 RNA干扰 白血病细胞耐药 

分 类 号：R733.7[医药卫生—肿瘤]