E2F-1在胃腺癌细胞内质网应激反应中对Mcl-1的调控作用  

Regulation of Mcl-1 by E2F-1 in endoplasmic reticulum stress in gastric adenocarcinoma cells

作　　者：王丽[1] 侯丽丽[1] 吴亚欧[1] 桂丽[1] 张旭东[1] 张林杰[1] 

机构地区：[1]安徽医科大学免疫学教研室,合肥230032

出　　处：《安徽医科大学学报》2011年第4期332-336,共5页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金(编号:30572118);安徽省自然科学基金(编号:070413077)

摘　　要：目的探讨Mcl-1在胃腺癌细胞对内质网应激诱导细胞凋亡耐受中的作用,以及内质网应激状态下E2F-1调控Mcl-1的机制。方法采用PI单染法测定细胞凋亡率;Western blot检测GRP78、Mcl-1、Bcl-2、E2F-1蛋白变化;实时荧光定量PCR检测Mcl-1 mRNA水平变化;转染pcDNA-E2F-1-Flag质粒使细胞高表达E2F-1。结果胃腺癌细胞对衣霉素(TM)诱导的内质网应激性凋亡相对不敏感,这与Mcl-1在蛋白水平和mRNA水平的上调有关。Mcl-1的转录抑制因子E2F-1在TM诱导细胞后表达下调。在内质网应激状态下的胃腺癌细胞中高表达E2F-1可以减弱Mcl-1的上调。结论内质网应激反应引起Mcl-1上调可能在胃腺癌细胞对内质网应激诱导的凋亡耐受中起重要作用;转录因子E2F-1下调可能参与调控Mcl-1的表达。Objective To explore the role of Mcl-1 in resistance of gastric adenocarcinoma cells to endoplasmic reticulum（ER） stress-induced apoptosis and the mechanism of regulation of Mcl-1 by E2F-1 in the cells under ER stress.Methods Apoptosis was measured by flow cytometry using propidium iodide staining.Western blot was used to detect expression levels of various proteins including GRP78,Mcl-1,Bcl-2 and E2F-1.The expression of Mcl-1 at mRNA level was monitored by quantitative RT-PCR.cDNA（pcDNA-E2F-1-Flag）transfection was employed to over-express E2F-1 in cells.Results Gastric adenocarcinoma cells were in general resistant to apoptosis induced by the ER-stress inducer tunicymicin（TM） which was associated with up-regulation of Mcl-1 in protein and mRNA levels.Intriguingly,the transcription factor E2F-1 known to repress transcription of Mcl-1 was decreased by exposure to TM.Over-expression of E2F-1 attenuated up-regulation of Mcl-1 in gastric adenocarcinoma cells under ER stress.Conclusion Up-regulation of Mcl-1 may play a role in resistance of gastric adenocarcinoma cells to ER stress-induced apoptosis.This is,at least in part,due to down-regulation of E2F-1 in the cells upon ER stress.

关 键 词：胃肿瘤 腺癌 E2F1转录因子 内质网 衣霉素 细胞凋亡 转染 

分 类 号：R735.2[医药卫生—肿瘤] R392.25[医药卫生—临床医学]