胃癌组织中p16基因甲基化与其蛋白表达的相关性及临床意义

Correlation of p16 gene methylation with protein expression in gastric cancer and its clinical significance

目的:探讨胃癌组织中p16基因甲基化与其蛋白表达的相关性及临床意义。方法:应用甲基化特异性PCR(methylation specific PCR,MSP)和免疫组织化学法分别检测28例胃癌和相应癌旁组织中p16基因启动子区CpG岛甲基化和p16蛋白的表达情况,并分析其与临床病理参数间的关系。结果:胃癌组织中p16基因甲基化率明显高于其相应的癌旁组织(P<0.01),并与胃癌的分化程度、浸润深度及淋巴结转移有关(P<0.05);p16蛋白在胃癌组织中的阳性表达率显著低于相应的癌旁组织(P<0.01);胃癌组织中p16基因甲基化与p16蛋白的表达之间呈负相关(r=-0.544,P=0.003)。结论:p16基因启动子区甲基化导致的基因沉默可能与胃癌的发生和发展密切相关。

Objective：To investigate the correlation of p16 gene methylation with protein expression in gastric cancer and its clinical significance.Methods：Methylation-specific polymerase chain reaction（MSP）was used to detected the CpG island methylation in promoter region of p16 gene in 28 gastric cancer tissues and corresponding adjacent tissues.The expression of p16 protein was examined by immunohistochemistry in these tissues.The relationship between the methylation status of p16 CpG island and clinical pathological parameters was analyzed.Results：The rate of methylation of p16 gene in gastric cancer tissues was higher than that in corresponding adjacent gastric tissues（P〈0.01）.The methylation of p16 gene correlated with differentiation,depth of invation and lymph node metastasis（P〈0.05）.The positive expression rate of p16 protein in gastric cancer tissues was lower than that in corresponding adjacent gastric tissues（P〈0.01）.Methylation of p16 gene was negatively related with expression of p16 protein in gastric cancer tissues（r=-0.544,P=0.003）.Conclusion：Gene silencing induced by promoter methylation of p16 gene has a close relationship with the tumorigenesis and development of gastric cancer.