结直肠癌原发灶和肝转移灶组织中蛋白质组差异表达及临床意义

目的探讨结直肠癌发生和肝转移相关蛋白及其与肝转移的关系。方法采用等电聚焦／SDS聚丙烯酰胺双向凝胶电泳法,对比分析结直肠癌原发灶、癌旁肠黏膜和肝转移灶中蛋白质组表达差异,经质谱分析、鉴定差异蛋白点;采用细胞转染方法,将差异蛋白基因导入到结直肠癌细胞,观察细胞生物学行为改变。结果结直肠癌原发灶、肝转移灶与正常肠黏膜蛋白质组分在PH7．0—9．5范围内有明显差别。分析13个差异蛋白点,其中2个蛋白点在癌原发灶组织中表达下调,5个蛋白点在原发灶组织中表达上调,6个蛋白点在肝转移组织中表达上调。经质谱鉴定,碳酸酐酶Ⅱ（CAⅡ）在癌组织中表达下调,磷酸甘油酸激酶Ⅰ、延胡索酸水合酶、醛缩酶A在原发灶中表达上调。精氨酸酶,谷胱甘肽S-转移酶A3在肝转移灶中表达上调。将碳酸酐酶ⅡcDNA克隆转染HR-8348细胞后,癌细胞侵袭、趋化运动能力及耐药性均明显减弱。结论结直肠癌原发灶和肝转移灶蛋白质组表达有显著差异,碳酸酐酶Ⅱ表达下调和精氨酸酶、谷胱甘肽S-转移酶A3增强表达可使结直肠癌细胞生物学行为发生改变并促进肝转移发生。

Proteome study of colorectal cancer genesis and hepatic metastasis

OBJECTIVE: To study differential proteins and their biological functions associated with colorectal cancer genesis and hepatic metastasis by proteomics and molecular biology techniques. METHODS: Isoelectric focusing/SDS acrylamide gel two-dimensional electrophoresis was used to analyse the expression of differential proteins from normal colorectal mucosa, primary cancer lesion and hepatic metastasis region. Liquid chromatography/mass spectrometry (LC-MS/MS) was used to identify the differential proteins. Transfection of colorectal cancer lovo cells was performed with the differential protein cDNA, and the changes of cell biological behavior was observed. RESULTS: Significant difference in protein expression was found on two-dimensional electrophoresis. Thirteen differential protein spots were analysed and identified. Human carbonic anhydrase II was detected in normal colorectal mucosa but not in primary cancer lesion and hepatic metastasisnegion. Phosphoglycerate kinase 1, fumarate hydratase and aldolase A were expressed in primary cancer. Expression of homo sapiens arginase and homo sapiens glutathione S-transferase A3 was found in hepatic metastasisnegion, but not in primary cancer lesion. After transfection with human carbonic anhydrase II cDNA, the lovo cells changed obviously with reduction in invasiveness, chemotaxy motor ability and tolerance. CONCLUSION: Differential expression of proteins was found between colorectal cancer genesis and hepatic metastasisnegion. No carbonic anhydrase II expression and enhanced expression of sapiens arginase and sapiens glutathione S-transferase A3 are related with biological behavior of colorectal cancer cell and facilitate hepatic metastasis.