胃癌组织中Runx3基因启动子甲基化及其蛋白的表达

目的探讨胃癌组织中Runx3基因启动子甲基化与其蛋白表达的相关性，并分析Runx3基因异常甲基化与胃癌临床病理因素的关系。方法分别采用甲基化特异性聚合酶链反应技术及免疫组织化学方法检测40例胃癌及其配对正常胃黏膜组织中Runx3基因启动子区的甲基化状态和Runx3蛋白表达。结果胃癌组织中Runx3基因启动子区甲基化发生频率（55．0％）明显高于正常胃黏膜组织（12．5％）（P〈0．01）；胃癌组织中Runx3蛋白表达阳性率（37．5％）明显低于正常胃黏膜组织（100％）（P〈0．05）；Runx3基因甲基化与肿瘤的组织分化程度、淋巴结转移数目及TNM分期密切相关（P〈0．05，P〈0．01）。结论启动子区高甲基化是胃癌组织中Runx3基因表达失活的主要机制，有望成为胃癌分子诊断和病期评估的标志之一。

Promoter methylation and expression of Runx3 gene in gastric cancer

OBJECTIVE: To analyze the relationships among the aberrant methylation of Runx3 gene promoter, the Runx3 protein expression and clinicopathological features in gastric cancer. METHODS: Methylation specific PCR was used to measure the promoter methylation status of Runx3 gene in tumor and the adjacent normal mucosal tissues from 40 patients with gastric cancer. Protein expression of Runx3 was measured by immunohistochemistry. RESULTS: The frequency of promoter methylaion of Runx3 gene in gastric cancer tissue(55.0%) was significantly higher compared to the adjacent normal tissues (12.5%)(P<0.01). The positive rate of protein expression of Runx3 in gastric cancer tissue(37.5%) was significantly lower compared to the adjacent normal tissues (100%). There was marked association between hypermethylaion and negative protein expression (P<0.05). The frequency of Runx3 promoter methylaion was associated with histological type, N grade, and tumor stage. CONCLUSION: The promoter hypermethylation is a main mechanism of reduced or loss expression of Runx3 gene, which may provide molecular diagnosis and stage evaluation of gastric cancer.