散发性肝外胆管癌中RASSF1A基因启动子甲基化状态的研究

Methylation status of RASSF1A gene promoter in sporadic extrahepatic cholangiocarcinoma

目的 检测肝外胆管癌组织中RASSF1A基因启动子甲基化及各CpG位点甲基化发生率。方法 采用甲基化特异性聚合酶链反应 (MS PCR)和半巢式PCR对RASSF1A基因启动子区域进行扩增 ,并对扩增产物克隆测序。结果 在全部 48例肝外胆管癌组织中 ,RASSF1A基因启动子区域存在CpG位点甲基化现象的共 2 8例 ,16个CpG位点甲基化平均发生率为 42 .45 % ,明显高于对照组 (χ2 =11.77,P <0 .0 1)。结论 RASSF1A基因启动子区域CpG岛甲基化是RASSF1A失活的主要机制 ,在肝外胆管癌的发生过程中发挥重要作用。

Objective To investigate the methylation status and frequency of CpGs islands in the promoter area of RASSF1A gene.Methods The methylation status was studied by methylation specific PCR (MS PCR) and semi nested PCR.The frequency of every CpGs island was analyzed using Bisufite Squencing.Results There were 28 samples which had hypermethylation status in all 48 samples of extrahepatic cholangiocarcinoma with the average methylation rate of all 16 CpGs sites in the promoter area being 42.45%,which was higher than in the contral group significantly ( χ 2 = 11.77, P < 0.01). Conclusion The hypermethylation of CpGs islands in the promoter area is the main mechanism in inactivation of RASSF1A gene,and may play an important role in the tumorigenesis of extrahepatic cholangiocarcinoma.