SM22蛋白在结肠癌组织中的表达

目的 通过比较结肠腺癌与正常结肠黏膜的蛋白质组表达差异,寻找结肠腺痛相关的蛋白质.方法 运用蛋白质组学技术,对8例结肠腺癌组织和8例正常结肠黏膜组织进行胶内差异双向电泳(2-D),选择差异表达超过2倍的蛋白质进行MALDI-TOF/TOF质谱分析和生物学信息分析,并对结肠癌组织中表达下调的蛋白SM22进行Western blot验证.结果 成功建立结肠腺癌和正常结肠黏膜的双向凝胶电泳图谱,结肠腺癌和正常黏膜组织凝胶电泳图谱中平均蛋白质斑点数分别为3289和3122,其中表达差异超过2倍的斑点共有22个,质谱分析和数据库检索共鉴定出14种蛋白质,包括keratin 8、S100A6、protein disulfide isomerase、SM22等.从功能分析,这些差异蛋白与癌细胞的发生、增殖、分化、转移等相关;SM22在结肠癌组织中的表达水平Western blot结果与电泳结果一致.结论 蛋白质组学能提示结肠腺癌与正常组织间的蛋白质表达差异,SM22在结肠癌组织中表达下降,可作为结肠癌组织的分子标记物.

Downregulation of SM22 protein expression in colon adenocarcinoma

Objective To investigate the cancer associated proteins in colon adenocaminoma by using proteomic technique.Methods Two-dimensional gel electrophoresis wag used to define patterns of protein expression in adenocarcinoma tissue from 8 patients with matched normal colonic mucosa.Proteins expressed differenfly of a 2-fold change were cut and analyzed bv MALDI-TOF/TOF mass spectrometry.Results Two-dimensional protein maps of adenocarcinoma and adenoma were gained successfully.Gel-analysis software identified an average of 3289 spots in adenocarcinoma.while 3122 in normal mucosa,and statistical filtering yielded 22 spots of a 2-fold change,14 of which were identified by using mass spectrometry,including keratin 8,S100A6,protein disulfide isomerase,SM22,etc.Functional analysis revealed that these proteins were associated with adenocarcinoma cellular oncogenesis,proliferation.differentiation,metastasis.etc.The expression level of SM22 in colon adenocarcinoma was validated by Westem blot.Conclusion Proteomic analysis can identify the proteins with variance of colon adenocarcinoma versus norinal colonic mucosa.Downregulation of SM22 might serve as a new biomarker of colon adenocarcinoma.