摘要
目的研究P21蛋白和凋亡相关基因XIAP在美伐他汀诱导A549细胞凋亡中的作用及其分子机制。方法应用MTT法检测细胞系的增殖作用,流式细胞仪、透射电镜检测细胞周期和凋亡;用流式细胞术、Western blot和RT-PCR检测P21蛋白、XIAP蛋白及P21和XIAP mRNA的表达。结果美伐他汀呈剂量和时间依赖性对A549增殖产生抑制;并诱导A549细胞G0/G1期阻滞和凋亡。美伐他汀对P21 mRNA及P21总蛋白的表达无影响,但可使P21胞膜蛋白的表达下降。美伐他汀作用后XIAP mRNA及XIAP蛋白的表达均下降。加入甲羟戊酸可完全逆转美伐他汀的上述作用。结论美伐他汀通过甲羟戊酸途径抑制A549细胞增殖并诱导凋亡,使细胞周期进程阻滞于G0/G1期,XIAP参与美伐他汀诱导A549细胞凋亡的基因调控。美伐他汀靶向HMG-CoA还原酶,抑制P21蛋白异戊二烯化、阻止P21蛋白与细胞膜的结合,不影响P21总蛋白的表达。
Objective To investigate the role of P21 protein and XIAP on apoptosis-inducing effect by mevastatin against A549 cell line and its mechanisms. Methods The cells proliferation was detected by MTT assay. The cell cycle distribution and apoptosis induction were evaluated with flow cytometer and electron microscopy. The mRNA expression of P21 and XIAP was measured with reverse transcription-polymerase chain reaction. The protein expression of P21 and XIAP was tested with flow cytometer and Western Bolt respectively. Results Mevastatin inhibited A549 cell survival in a time-dependent and concentration-depended manner. Flow cytometry showed that mevastatin induced G0/G1 phase arrest and caused apoptosis. Mevastatin did not affect P21 expression at both mRNA and total protein level. Concomitantly, P21 protein localized on cellular membrane decreased. Both mRNA and protein expression in XIAP were down regulated by mevastatin. All these effects were reversed by mevalonate. Conclusion Mevastatin can inhibite proliferation, induce apoptosis and interfere with cell progression of A549 through mevalonate pathway. Its mechanisms are explained by decreasing the expression of XIAP mRNA and protern. Targeting HMG- CoA reductase, Mevastatin blocks the isoprenylation of P21 protein which affects its anchorage on the cellular membrane.
出处
《基础医学与临床》
CSCD
北大核心
2007年第9期1015-1020,共6页
Basic and Clinical Medicine
