肝癌细胞蛋白质组在DTT诱导内质网应激条件下的表达

Proteomic profiling of human hepatocellular carcinoma SMMC-7721 cells under endoplasmic reticulum stress induced with dithiothreitol

目的:研究内质网应激条件下肝癌细胞SMMC-7721蛋白质组的表达,为人类肝细胞癌的诊治提供新的靶点.方法:培养肝癌细胞株SMMC-7721,随机分为两组,即实验组和对照组.实验组加入二硫苏糖醇(DTT,2.5mmol/L),对照组加入等量的培养基,裂解细胞,提取全细胞蛋白.双向电泳(2-DE)分离,Image Master2D Platinum软件进行差异表达蛋白质组分析,基质辅助激光解吸附离子化飞行时间质谱(MALDI-TOF-MS)鉴定蛋白质.结果:实验组肝癌细胞SMMC-7721的2-DE图谱上共检出蛋白质斑点(844±46)个,对照组共检出蛋白质斑点(1015±63)个,对照组与实验组自动匹配配对(593±23)对,匹配率约71%左右,绝大多数蛋白集中于pH5.2-6.5,相对分子质量15000-80000Da;获得组间标准化总灰度值(%Vol)相差2倍及以上的蛋白斑点3个,通过MALDI-TOF-MS分析鉴定了3个差异蛋白质点,分别是:fem-1同源蛋白B、细胞周期素A1、增殖诱导蛋白44.结论:鉴定的3个肝癌细胞株SMMC-7721在内质网应激下表达改变的蛋白质,其功能涉及细胞增殖、细胞凋亡以及细胞周期等,具有潜在的作为肝癌诊断、预后标记物或治疗靶点的意义.

AIM：To explore new therapy targets for human hepatocellular carcinoma by proteomic profiling of human hepatocellular carcinoma SMMC-7721 cells under endoplasmic reticulum stress.METHODS：Cultured SMMC-7721 cells were divided into two groups：experimental group and control group.The experimental group was treated with dithiothreitol（DTT,2.5 mmol/L）,while the control group was treated with equal volume of culture medium.After treatment,total cell proteins were prepared and resolved by two-dimensional electrophoresis（2-DE）.The two-dimensional electrophoresis maps for the two groups of cells were analyzed using ImageMaster 2D Platinum software.Proteins that showed obvious expression alteration in the experimental group were identified by matrixassisted laser desorption ionization time-offlight mass spectrometry（MALDI-TOF-MS）.RESULTS：There were 844±46 protein spots in the 2-DE map for the experimental group and 1 015±63 protein spots for the control group.There were 593±23 pairs of matched protein spots between the two groups,and the matching rate was about 71%.Most of the proteins have an isoelectric point at pH5.2-6.5 and a molecular weight of 15 000-80 000 Da.Three protein spots showed 2-fold or greater differential expression between the two groups and were identified by MALDI-TOF-MS.They were protein fem-1 homolog B,cyclin A1,and proliferation-inducing protein 44.CONCLUSION：Three differentially expressed proteins in SMMC-7721 cells under endoplasmic reticulum stress were identified and may be useful molecular targets for the diagnosis and treatment of hepatocellular carcinoma.