大肠癌发生和肝转移的蛋白质组学研究

目的 利用蛋白质组研究技术分离、鉴定大肠癌肝转移相关蛋白。方法 用等电聚焦／SDS聚丙烯酰胺双向凝胶电泳对比分析12例大肠癌患者原发灶、癌旁肠黏膜和肝转移灶中疏水蛋白表达差异,经肽质量指纹谱分析、鉴定差异蛋白点。结果 双向电泳图像对比分析表明,正常结直肠黏膜组织、癌原发灶和肝转移灶中蛋白质表达有显著差异。对9个差异表达蛋白点分析鉴定,钙调蛋白联合体、核糖核酸酶-6-前体蛋白以及XP-040720蛋白在正常肠黏膜表达,但在癌原发灶和肝转移组织中表达缺失。前阿朴脂蛋白在正常肠黏膜、癌原发灶及肝转移灶中呈递增表达。β-珠蛋白在肝转移灶和正常肠黏膜中表达,而在癌原发灶中表达缺失。Cdc42蛋白在肝转移灶中特异表达。差异蛋白点C4、N7和N9肽指纹谱与已知蛋白同源性低,为候选大肠癌发生和肝转移相关新蛋白。结论 钙调蛋白联合体、核糖核酸酶-6-前体蛋白、α-甘露糖苷酶Ⅰ表达缺失与大肠癌发生和肝转移有关;前阿朴脂蛋白增强表达与大肠癌发生和肝转移有关;Cdc42蛋白、β-珠蛋白表达与肝转移有关。

Proteome study of colorectal cancer genesis and hepatic metastasis

OBJECTIVE: To study differential expression proteins associated with colorectal cancer genesis and hepatic metastasis with proteomic techniques. METHODS: Using isoelectric focusing/SDS acrylamide gel two-dimensional electrophoresis to analyse differential expression protein spots among normal colorectal mucosa, primary cancer lesion and hepatic metastasis. Peptide mass fingerprinting was used to identify the differential proteins. RESULTS: Significant differences of protein expression were found on two-dimensional electrophoresis. Nine differential protein spots were analysed and identified. Calmodulin, ribonuclease 6 precursor and protein XP_040720 (mannosidase-alpha) were detected in normal colorectal mucosa, but lost in primary cancer lesion and hepatic metastasis. Proapolipoprotein was expressed progressively from normal mucosa to primary cancer and hepatic metastasis. Expression of beta-globin was found in normal mucosa and hepatic metastasis, but not in primary cancer lesion. Cdc42 was a differential expression protein in hepatic metastasis. Peptide mass fingerprints of differential protein spot C4, M7 and M9 had low homology with database proteins, they were candidates of associated proteins with colorectal cancer genesis and hepatic metastasis. CONCLUSION: Loss of calmodulin, ribonuclease 6 precursor and mannosidase-alpha expression are associated with colorectal cancer genesis. Enhancement expression of proapolipoprotein is related with colorectal genesis and hepatic metastasis. Cdc42 and beta-globin are associated proteins with hepatic metastasis of colorectal cancer.