ERK参与裸鼠体内辛伐他汀诱导K562细胞凋亡的调控作用  

ERK was involved in the regulation of simvastatin-induced apoptosis of K562 cells in nude mice

作　　者：周定安[1] 黄文方[2] 刘华[2] 杨永长[2] 黄波[1] 胡琦[1] 

机构地区：[1]重庆医科大学检验系,重庆400016 [2]四川省医学科学院,四川省人民医院检验科,成都610072

出　　处：《肿瘤》2008年第1期17-20,共4页Tumor

基　　金：四川省卫生厅基金项目(编号:303005002061011)

摘　　要：目的:探讨辛伐他汀(simvastatin)作用于裸鼠体内K562细胞后Ras-MAPK信号转导通路胞外信号调节激酶(extra-cellular signal-regulated protein kinase,ERK)分子水平的变化,以说明ERK参与裸鼠体内辛伐他汀诱导K562细胞凋亡的调控作用。方法:体外培养慢性髓细胞白血病(CML)细胞株K562细胞,构建BALB/c-nu/nu裸鼠的K562细胞移植瘤模型。流式细胞术(FCM)检测对照组和两个辛伐他汀处理组的K562细胞周期变化,TUNEL法检测K562细胞晚期凋亡情况。采用RT-PCR检测K562细胞中Ras-MAPK信号通路N-Ras、ERK1 mRNA的差异表达。免疫组织化学标记葡聚糖聚合物(labbled dextran polymer,LDP)法检测P-ERK蛋白水平变化。结果:辛伐他汀能够明显抑制裸鼠K562移植瘤组织的增长,随着辛伐他汀剂量的增加,K562细胞移植瘤体积和质量明显减小(P<0.05,P<0.01)。每次注射0.05mg的辛伐他汀能够诱导裸鼠体内K562细胞发生明显的G0/G1期停滞,不同剂量的辛伐他汀能够诱导K562细胞发生明显的凋亡,并随剂量的增加,凋亡率逐渐增高(P<0.01);不同剂量的辛伐他汀能够引起N-Ras、ERK1 mRNA的表达下调(P<0.01)。与对照组相比,两个处理组的p-ERK蛋白分别出现表达下调(P=0.01,P<0.01)。结论:辛伐他汀在体内可能依赖Ras-MAPK信号转导通路ERK基因和蛋白水平的表达下调诱导K562细胞凋亡发生。Objective：To investigate the molecular change of extracellular signal-regulated protein kinase（ERK） in Ras-MAPK signaling pathway after K 562 cells in nude mice were treated with simvastatin to elucidate whether ERK is involved in the regulation of simvastatin-induced apoptosis of K 562 cells. Methods：K 562 cells, the chronic myeloid leukemia （CML） cell line, were cultured in vitro and used to establish the K 562 xenografted model in BALB/c-nu/nu mice. The cell cycle of K 562 cells of control and two treatment groups was detected by flow cytometry （FCM）. The advanced stage apoptotic change of K 562 cells induced by simvastatin was detected by TdT-mediated dUTP nick end labeling （TUNEL）. The differential expressions of N-Ras and ERK 1 mRNA in Ras-MAPK signaling pathway were detected by RT-PCR. The changes of p-ERK protein were measured by immunohistochemical LDP method. Resuits. Simvastatin markedly inhibited the growth of xenografted K 562 tumor in nude mice. The volume and weight of tumors were significantly reduced with the increase in the dosage of simvastatin （ P 〈 0.05, P 〈 0.01 ）. Injection of 0.05 mg simvastatin per time induced significant G0/G1 arrest of K 562 cells in nude mice. Apoptosis of K 562 cells of nude mice could be induced by simvastatin at different dosages and the apoptotic rate was elevated by increasing the dosage of simvastatin （P 〈 0.01 ）. The mRNA expressions of N-Ras and ERK 1 mRNA in K 562 cells were down-regulated by simvastatin at different dosages （P 〈 0.01 ）. Compared with the control group, the p-ERK protein expression was down-regulated in 2 simvastatin-treated groups （P = 0.01, P 〈 0.01 ） , respectively. Conclusion： Simvastatin depends on the Ras-MAPK signaling pathway. Downregulation of ERK mRNA and protein is involved in the induction of apoptosis of K 562 cells by simvastatin.

关 键 词：肿瘤 实验性 辛伐他汀 白血病 髓样 慢性 ERK 细胞凋亡 小鼠 近交BALB c 

分 类 号：R730.231[医药卫生—肿瘤] R733.72[医药卫生—临床医学]