APC和CDKN2A基因甲基化定量分析对肝细胞癌的诊断价值

Clinical implications of quantitative methylation analysis of the adenomatous polyposis coli and cyclindependent kinase inhibitor 2A genes in hepatocellular carcinoma

目的:系统分析基因甲基化在肝癌发生中涉及的分子途径,从中选取代表性基因进一步分析其甲基化在细胞癌变过程中的生物学及临床意义.方法:对10年间关于肝癌基因甲基化相关文献进行数据发掘与功能分类,在其中2个与肝癌发生相关的生物途径中选取APC和CDKN2A基因,采用实时定量甲基化特异性PCR技术对46例成对肝癌与癌旁组织中基因的甲基化水平进行定量分析并评估其诊断价值.结果:生物信息学分析显示肝癌中发生甲基化的基因主要涉及Wnt/β-catenin、p16及p533个主要分子途径;甲基化分析表明CDKN2A基因在肝癌组织中甲基化水平极显著高于癌旁组织(P<0.0001),并且癌组织中甲基化程度在高龄患者中较高(P=0.0027);ROC曲线分析表明通过CDKN2A甲基化定量分析能够高效区分癌与非癌组织(AUC=0.8526).APC基因在癌与癌旁间总体甲基化水平无显著性差异(P=0.0656).结论:CDKN2A基因甲基化水平的升高在肝细胞癌变过程中可能具有重要作用,其甲基化水平的升高可作为一种鉴别癌与非癌组织的分子标志物.CDKN2A甲基化模式的特异性使其在肝癌早期筛查和诊断中具有一定的临床应用价值.

AIM： To investigate methylation-related molecular pathways associated with hepatocellular carcinogenesis and determine the clinical implications of representative genesinvolved in these pathways. METHODS： A PubMed search was performed to retrieve and analyze relevant publications during the past 10 years via literature mining. Related methylated genes were classif ied according to Gene Ontology criteria. The methylation of adenomatous polyposis coli （APC） and cyclindependent kinase inhibitor 2A （CDKN2A） genes was quantitatively determined in 46 paired tumor and adjacent non-tumor tissues by MethyLight assay. The methylation levels of the two genes were evaluated to determine their implications for diagnosis of hepatocellular carcinoma （HCC）. RESULTS： Bioinformatic analysis revealed that methylated genes were mainly involved in the Wnt/-catenin, p16 and p53 molecular pathways. The methylation level of CDKN2A was significantly higher in tumor tissues than in adjacent non-tumor tissues （P 〈 0.0001）. Moreover, the methylation level of CDKN2A was significantly higher in older patients than in younger ones （P = 0.0027）. Receiver operating characteristic （ROC） analysis demonstrated that CDKN2A methylation level could be used to distinguish neoplastic lesions from non-malignant tissues. CONCLUSION： Elevation of CDKN2A methylation level may play an important role in hepatocarcinogenesis. CDKN2A methylation level can serve as a biomarker for distinguishing tumor tissues from non-tumor tissues and be used for screening or diagnosis of HCC.