AFP基因启动子区甲基化与其表达的关系

【目的】研究细胞系中AFP基因启动子甲基化模式与其基因表达的关系。【方法】应用RT-PCR方法检测人源HepG2、SMMC-7721肝癌细胞系和人成纤维细胞中AFP基因的表达,应用甲基化特异性聚合酶链反应（MS-PCR）法和亚硫酸氢盐-DNA测序法检测AFP基因启动子甲基化密度及特定位点的甲基化水平。【结果】HepG2细胞高表达AFP,AFP基因启动子非甲基化程度较高;SMMC-7721细胞低表达AFP,AFP基因启动子部分甲基化;正常细胞不表达AFP,AFP基因启动子甲基化程度很高;位于AFP全基因组序列-2494bp,-2431bp处的两个CG位点有可能作为肝癌的检测位点。【结论】AFP基因启动子甲基化程度与基因表达水平存在负相关,AFP基因沉默与其启动子甲基化有关,AFP基因启动子低甲基化可能是AFP高表达的分子机理。

Analysis on the methylation of the promoter of AFP gene and its expression

[Objective] To study the relationship between the methylation patterns of AFP gene promoter and the expression of AFP in cell lines. [Methods] AFP gene expression was detected in HepG2, SMMC-7721 and ribroblasts by RTPCR. The methy]ation status of the promoter CG sites of AFP gene was also investigated by means of MS-PCR and bisulrite-sequencing. [Results] Methylation of AFP gene was found at GC-box and not expressed in HepG2 cell lines, but unmethylatedand expressed in SMMC-7721 cell lines. [Conclusion] The methy]ation partterns of AFP gene promoter in HepG2, SMMC-7721 cell lines and fihroblasts are different, AFP gene silencing is associated with the promoter methyiation.