目的：探讨肝癌细胞中NFAT2基因启动子CpG岛甲基化状态及与其mRNA表达的关系。方法：用重硫酸盐测序法检测肝癌组织与癌旁组织及不同肝细胞系与正常肝细胞中NFAT2启动子甲基化状态，用qRT-PCR检测肝癌组织与癌旁组织NFAT2 mRNA表达，并分析肝癌组织NFAT2启动子甲基化与mRNA水平的相关性。结果：肝癌组织中NFAT2基因CpG岛甲基化率明显高于癌旁组织（33.0% vs. 21.6%，P=0.003）；人肝癌细胞系HuH7、HepG2、Hep3B中NFAT2基因CpG岛甲基化率分别为34.8%、40.4%、37.0%，均明显高于人正常肝细胞系L02中NFAT2基因CpG岛甲基化率（16.2%）（均P<0.05）。肝癌组织NFAT2 mRNA相对表达量明显低于与癌旁组织（0.000 602 4 vs. 0.001 469，P<0.05），肝癌组织中NFAT2 mRNA水平与其启动子甲基化程度呈明显负相关（r=-0.661，P=0.027）。结论：肝癌细胞中NFAT2基因表达下调可能与其启动子区CpG岛高甲基化状态有关。
Relationship between promoter methylation and mRNA expression of NFAT2 gene in hepatocellular carcinoma cells
Objective: To investigate the methylation status of CpG islands in the promoter region of NFAT2 gene and its relation with the NFAT2 mRNA expression in hepatocellular carcinoma (HCC) cells. Methods: The methylation status of CpG islands in the promoter region of NFAT2 in HCC and the tumor-adjacent tissues as well as in different HCC cell lines and normal hepatic cells was examined by bisulfite-sequencing PCR. NFAT2 mRNA expression in HCC and the adjacent tissues was determined by qRT-PCR, and the correlation between NFAT2 promoter methylation and its mRNA expression was analyzed. Results: The CpG island methylation rate of NFAT2 gene in HCC tissue was significantly higher than that in tumor-adjacent tissues (33.0% vs. 21.6%, P=0.003); the CpG island methylation rate of NFAT2 gene in HCC cell line HuH7, HepG2 and Hep3B was 34.8%, 40.4% and 37.0% respectively, which were all significantly higher than that in human normal hepatic cell L02 (16.2%) (all P<0.05). The NFAT2 mRNA expression in HCC tissue was significantly lower than that in tumor-adjacent tissues (0.000 602 4 vs. 0.001 469, P<0.05), and there was a negative correlation between the NFAT2 mRNA level and the degree of NFAT2 promoter methylation (r=–0.661, P=0.027). Conclusion: Down-regulated NFAT2 gene expression is probably associated with hypermethylation of CpG islands in its promoter region in HCC cells.