转录因子XBP1S对人肝癌HepG2细胞增殖及凋亡的影响  

Effects of transcription factor XBP1S on cell proliferation and apoptosis of hepatoma HepG2 cells

作　　者：林建炜[1,2] 刘平[1] 向廷秀[3] 李祥柱[1] 赵文君[1] 郭风劲[1,2] 

机构地区：[1]重庆医科大学细胞生物学及遗传学教研室,重庆400016 [2]重庆医科大学分子医学与肿瘤研究中心,重庆400016 [3]重庆医科大学附属第一医院分子肿瘤及表观遗传学实验室,重庆400016

出　　处：《肿瘤》2011年第1期11-16,共6页Tumor

基　　金：国家自然科学基金资助项目(编号:31040019);教育部留学回国人员科研启动基金资助项目[编号:教外司留(2009)1590号]

摘　　要：目的:探讨人剪接型X盒结合蛋白1(X-box binding protein1spliced,XBP1S)对肝癌HepG2细胞增殖和凋亡的影响。方法:应用衣霉素(tunicamycin,Tm)和毒胡萝卜素(thapsigargin,Tg)建立HepG2细胞的内质网应激(endoplasmic reticulum stress,ERS)模型。将XBP1S真核表达载体pcDNA3.1(-)-XBP1S和靶向XBP1S的RNA干扰质粒pSUPER-XBP1S转染HepG2细胞,MTT法检测细胞的增殖能力,荧光显微镜下观察细胞的形态学变化,FCM法检测细胞凋亡率,Western印迹法检测caspase12的表达。结果:转染pSUPER-XBP1S可有效抑制细胞增殖,而转染pcDNA3.1(-)-XBP1S可促进细胞增殖。荧光显微镜下可见Tm处理组细胞出现细胞凋亡的形态学改变,进一步下调XBP1S的表达可使这一改变增强。对照组、Tm组、Tm+pSUPER-XBP1S转染组和Tm+pcDNA3.1(-)-XBP1S转染组细胞的凋亡率分别为5.21%、41.51%、52.15%和35.87%,差异有统计学意义(P<0.05)。HepG2细胞中caspase12的表达,Tm组高于对照组,Tm+pSUPER-XBP1S转染组高于Tm组,Tm+pcDNA3.1(-)-XBP1S转染组低于Tm组。结论:XBP1S可以促进肝癌HepG2细胞增殖,抑制或促进XBP1S表达可调节ERS介导的细胞凋亡。Objective： To study the effects of X-box binding protein 1 spliced （XBP1S） on cell proliferation and apoptosis of hepatoma HepG2 cells. Methods： The endoplasmic reticulum stress （ERS） model of HepG2 cells was constructed and induced by tunicamycin （Tm） and thapsigargin （Tg） . XBP1S eukaryotic expression vector pcDNA3.1 （-） -XBP1Sand targetXBP1S RNAinterference plasmid pSUPER- XBP1S were transfected into HepG2 cells. Cell proliferation was measured by MTT assay. The morphology changes of cells were observed under a fluorescence microscope. The apoptosis was detected by flow cytometry. The expression of caspase12 protein was determined by Western blotting. Results： The proliferation of HepG2 cells was inhibited after transfection with pSUPER-XBP1S, but that was improved after transfection with pcDNA3.1 （-） -XBP1S. The apoptotic morphologic changes were obvious in Tm- treated group, and this effect was enhanced by down-regulation of XBP1S expression. The apoptotic rates of cells in the control, Tm-treated, Tm plus pSUPER-XBP1S-transfected and Tm plus pcDNA3.1 （-） -XBP1S-transfected groups were 5.21%, 41.51%, 52.15% and 35.87%, respectively （P〈O.05） . The expression levels ofcaspase12 were gradually increased in the controI, Tm plus pcDNA3.1 （-） -XBP1S- transfected, Tm-treated and Tm plus pSUPER-XBP1S -transfected groups. Conclusion： XBP1S can improve the proliferation of HepG2 cells. Up- or down-regulation of XBP1S expression level maybe regulate ERS- mediated apoptosis of HepG2 cells.

关 键 词：肝肿瘤 X盒结合蛋白1 内质网应激 细胞增殖 细胞凋亡 细胞 HepG2 

分 类 号：R735.7[医药卫生—肿瘤]