胃癌肝转移相关基因的克隆鉴定

Identification of hepatic metastasis-related genes in gastric cancer

目的克隆胃癌肝转移的相关基因。方法将标本分成有肝转移和无肝转移的胃癌原发灶两组,每组9例。提取组织总RNA,反转录成cDNA,将RT-PCR的扩增产物在PAGE测序胶上电泳,经EB染色分离两组差异表达的基因片段,TA克隆差异片段后进行测序,用GenBank BLAST软件进行同源性分析。将其中获得的1个与人内源性逆转录病毒基因片段做为标志物,用RT-PCR检测其在肝转移胃癌、无肝转移胃癌组织中的表达。结果有肝转移与无肝转移胃癌组织之间存在明显的基因表达差异,差异明显的10个基因片段均呈高表达。与人内源性逆转录病毒同源的基因片段在有肝转移胃癌组织中有7例表达,在无肝转移胃癌组织中有2例表达(P=0．007)。结论肝转移以胃癌癌基因突变为主,人内源性逆转录病毒基因片段在有肝转移胃癌组织中的表达高于无肝转移胃癌组织。

Objective To identify liver metastasis-related genes in gastric cancer. Methods Total RNA were extracted from cancer tissues in 9 patients with liver metastasis and in 9 without. After cDNA were synthesized by MMLV and anchored-primer, PCR were amplified using anchored-primers and random primers. The differential fragments coming from different PCR products were displayed in PAGE and TA cloned. After DNA sequencing, the data were BLAST in GenBank database for homology analysis. Results There were differential expression patterns among gastric cancers with or without hepatic metastasis. All the 10 differential gene fragments detected in gastric cancer tissues were on high expression. The gene fragments homologous with HERV nearly were more significantly expressed in the samples with liver metastasis （7/9） than the samples without liver metastasis （2/9）. Conclusions Most liver metastasis are from mutation of gastric oncogene. HERV gene expression was higher in the gastric cancer tissues in patients with liver metastasis than that without metastasis.