胃癌RASSF1A基因启动子CpG岛甲基化与DNMT1表达的意义

目的探讨RAS相关区域家族1A（RASSF1A）基因启动子CpG岛甲基化和DNA甲基转移酶1（DN-MT1）的表达与胃癌发生的关系。方法运用甲基化特异性聚合酶链反应和免疫组织化学方法检测胃癌癌旁正常组织和癌组织RASSF1A基因启动子CpG岛甲基化发生率及DNMT1的表达情况。结果癌旁正常组织中RASSF1A基因启动子CpG岛甲基化发生率、DNMT1阳性表达率显著低于相应癌组织（P均〈0.01）。RASSF1A启动子CpG岛甲基化患者DNMT1阳性表达率与非甲基化患者比较无统计学差异（P〉0.05）。结论RASSF1A基因启动子区CpG岛甲基化和DNMT1的高表达可能与胃癌发生有一定关系。

Relationship between methylation of promoter of gene RASSF1A in gastric cancer and expression of DNMT1

Objective To analyze the methylation of promoter of gene RASSF1A and the expression of protein DNMT1 in gastric cancer tissue, further identify gene RASSF1A and protein DNMT1 and their relationship with gastric carcinogenesis. Methods Apply MSP and IHC to detect methylation of promoter of gene RASSF1A and the expression of protein DN- MT1 in adjacent normal tissue and cancer tissue of gastric cancer samples. Results The incidence rate of mythelation in CpG island and the positive rate of DNMT1 in adjacent normal tissue rate were far less than that of corresponding cancer tissues, and there was significant difference between them （ P 〈 0.01 ）. The positive rate of DNMT1 in methylation group was higher than that in un-methylation group, however, there was no significant difference between them （P 〉 0.05 ）. Conclusions The methylation of promoter area of RASSF1A and the expression of DNMT1 are recurrent event for gastric carcinogenesis, and maybe correlate with it.