河南林州地区贲门癌和癌旁组织中p16基因启动子甲基化及蛋白表达

目的探讨贲门癌变过程中p16基因启动子区甲基化和p16蛋白表达变化特征和规律及其相互关系。方法采用甲基化特异PCR（MSP）及免疫组化方法,检测林州地区32例贲门癌患者癌组织、癌旁不典型增生组织和正常组织p16基因启动子区甲基化状态及蛋白表达情况。结果p16基因在癌组织中表达缺失18例（56%）,不典型增生组织中表达缺失8例（73%）;26例（81%）癌组织、7例（64%）不典型增生组织和18例（67%）正常组织发生了p16基因启动子区的甲基化。贲门癌组织中p16基因甲基化与表达缺失一致率为56%。差异无统计学意义,P〉0.05。结论p16蛋白表达缺失可能是贲门癌变过程中的重要分子事件,p16基因启动子区甲基化可能是导致其蛋白表达缺失的机制之一。

Promoter hypermethylation and protein expression of p16 gene in gastric cardia adenocarcinoma and adjacent non-cancer tissues in Linzhou, Henan Province

OBJECTIVE: To characterize the p16 protein expression and promoter hypermethylation in gastric cardia carcinogenesis. METHODS: Immunohisto-chemistry and methylation specific PCR were used to detect p16 protien expression and p16 gene promoter methylation in adjacent non-cancer tissue, dysplasia tissue (DYS) and gastric cardia adenocarcinoma (GCA) from 32 patients with GCA, respectively. RESULTS: Aberrant expression rates of p16 protein were 18(56%) and 8(73%) in GCA and DYS tissues, respectively. The prevalence of p16 gene hypermethylation was 26(81%), 7(64%) and 18(67%) in GCA, DYS and normal tissues, respectively. The confordence rate of promotor methylation and expression dletion of p16 gene in GCA tissues was 56%, it did not have statistic difference in confordence, P>0.05. CONCLUSION: Aberrant expression of p16 is one of frequent molecular events in gastric cardia carcinogenesis and p16 hypermethylation may be one of mechanisms leading to p16 protein aberrant expression.