IEX-1蛋白在胃癌中的表达及其意义

Expression of IEX-1 protein in gastric carcinoma and its effect on apoptosis and proliferation of human gastric cancer cells

目的揭示即刻早期反应X-1(IEX-1)蛋白在胃癌组织及细胞系中的表达,探讨其对人胃癌细胞凋亡和增殖的影响。方法采用免疫组织化学法检测100例胃镜活检标本中IEX-1蛋白的表达,用实时荧光定量聚合酶链反应和Western blot检测人正常胃黏膜细胞GES-1和胃癌细胞MKN28中IEX-1基因和蛋白的表达,同时转染IEX-1的过表达质粒pc DNA3-FLAG-IEX-1和干扰质粒p LL3.7-si-IEX-1,分别采用流式细胞术及四甲基偶氮唑盐比色法检测IEX-1对细胞周期、凋亡及增殖的影响。结果胃癌组织中IEX-1蛋白表达水平高于正常胃组织和慢性胃炎组织(P<0.05),且随着病情进展,IEX-1表达水平有逐渐升高的趋势。相对于人正常胃黏膜细胞GES-1,胃癌细胞MKN28中IEX-1基因和蛋白表达更高(P<0.05)。与对照组相比,IEX-1蛋白表达增高后S期细胞比例升高,G2期细胞比例降低,细胞增殖率升高,凋亡减少(P<0.05),而干扰IEX-1蛋白表达后,G1期细胞升高,G2期细胞比例下降,细胞增殖率下降,细胞凋亡增加(P<0.05)。结论 IEX-1蛋白在胃癌组织中呈高表达,在人胃癌细胞中上调IEX-1蛋白能促进细胞增殖,发挥抗凋亡能力,干扰IEX-1蛋白表达能阻滞细胞周期进程,并诱导凋亡。

Objective To reveal the expression of IEX-1protein in gastric cancer tissues and cell lines,and investigate the effect of IEX-1on the proliferation and apoptosis of human gastric cancer cells.MethodsImmunohistochemistry was used to detect IEX-1protein expression in100samples of gastric mucosal biopsy.gene and protein expressions were detected by fluorescence qRT-PCR and Western Blot respectively innormal gastric mucosa GES-1cells and gastric cancer MKN28cells.pcDNA3-FLAG-IEX-1plasmid andpLL3.7-si-IEX-1plasmid were transfected into MKN28cells respectively,and then cell cycle,apoptosis andproliferation were detected by flow cytometry and MTT assay.Results The expression of IEX-1protein in thegastric cancer tissues was higher than that in the normal gastric tissues and the chronic gastritis tissues(<0.05),and the expression level of IEX-1was gradually increased with the progress of the disease.Theexpressions of gene and protein in the gastric cancer MKN28cells were higher than those in thenormal gastric mucosal GES-1cells(<0.05).Compared with the control group,the increased expression ofIEX-1protein could increase the proportion of the cells in S phase,decrease the proportion of the cells inG2phase,increase the rate of cell proliferation,and decrease apoptosis(<0.05).After the expression ofIEX-1protein was interfered,the percentage of G1phase cells increased,that of G2phase cells decreased,the rate of cell proliferation decreased,apoptosis increased(<0.05).Conclusions IEX-1protein is highlyexpressed in gastric cancer tissues.Up-regulation of IEX-1protein expression can promote the proliferation of human gastric cancer cells and play an anti-apoptotic role.Interfering with the expression of IEX-1proteincould block cell cycle progression and induce apoptosis.