口腔鳞状细胞癌Runt相关转录因子3启动子区CpG岛甲基化状态的研究

Research on the promoter hypermethylation of runt-related transcription factor 3 in oral squamous cell carcinoma

目的研究口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)中Runt相关转录因子3(runt-relatedtranscription factor 3,RUNX3)基因启动子区的甲基化状态与其表达及病理参数之间的相关性。方法应用逆转录聚合酶链反应和免疫组织化学技术分析10例口腔正常黏膜组织和30例OSCC组织中RUNX3 mRNA和蛋白的表达;应用甲基化特异性聚合酶链反应分析10例口腔正常黏膜组织和30例OSCC组织及其相应癌旁组织中RUNX3基因启动子区CpG岛甲基化状态;分析RUNX3启动子区甲基化及表达与临床病理参数之间的关系。结果 30例OSCC组织中,73.3%(22/30)呈现mRNA以及蛋白表达下调或缺失。30例OSCC组织及对应癌旁组织中CpG岛甲基化检出率分别为70.0%(21/30)和55.3%(16/30),两者之间差异无统计学意义(P=0.184)。统计学分析表明RUNX3的表达与其启动子区CpG岛高甲基化呈显著负相关(P=0.001),但发现其甲基化状态与临床病例参数间的关系无统计学意义。结论 OSCC中RUNX3的表达下调或缺失是一种常发事件,启动子区CpG岛高甲基化是其主要的失活机制,且后者可以发生在癌变的早期阶段。

Objective To analyze the promoter hypermethylation of runt-related transcription factor 3（RUNX3） in oral squamous cell carcinoma（OSCC）.Methods RUNX3 mRNA and protein expression were examined in 10 normal oral mucosa and 30 OSCC tissues by RT-PCR analysis and immunohistochemistry assay;the promoter hypermethylation of RUNX3 was analyzed in 10 normal oral mucosa,30 OSCC tissues and their matched adjacent normal tissues by methylation-specific polymerase chain reaction（MSP）;Finally,the relationships between the promoter hypermethylation of RUNX3 with RUNX3 expression and the clinicopathological parameters were statistically analyzed.Results In 30 OSCC samples,73.3%（22/30） cases showed decreased or absent expression of RUNX3 mRNA and protein;The promoter hypermethylation of RUNX3 could be detected in 70%（21/30） OSCCs and 55.3%（16/30） corresponding adjacent normal tissues.RUNX3 mRNA and protein expression were all significantly correlated with the promoter hypermethylation of the gene（P=0.001）.Conclusion Downregulation of RUNX3 occurred frequently in OSCCs,which was mainly caused by the promoter hypermethylationand of the gene.The promoter hypermethylation could occur in the early stage in oral carcinogenesis.