LMX1A基因启动子在胃癌中的异常甲基化研究

摘要

目的 研究LMX1A基因启动子在胃癌细胞中的甲基化状态.方法 运用甲基化特异聚合酶链反应(MSP)法检测30例原发胃癌和癌旁组织中LMX1A基因的甲基化水平.甲基化修饰后亚硫酸盐测序聚合酶链反应 (BSP)分析胃癌细胞MKN45细胞LMX1A基因启动子CpG岛甲基化状态.提取细胞RNA,通过实时定量聚合酶链反应(PCR)检测LMX1A基因 mRNA在不同浓度的DNA甲基化酶抑制剂5′-杂氮-2′-脱氧胞嘧啶(5-aza-dC)处理MKN45细胞后,LMX1A基因 mRNA的改变情况.结果 原发性胃癌的甲基化异常检出率是33%(10/30).LMX1A基因在MKN45细胞中存在高甲基化状态,MKN45细胞经5-aza-dC处理后LMX1A基因 mRNA表达明显上调.结论 LMX1A基因在原发性胃癌中存在甲基化异常,说明LMX1A基因甲基化异常可能参与胃癌的发生.%Objective To detect the methylation status of LMX1A promoter in gastric cancer cells. Methods Thirty primary gastric cancer tissues and corresponding normal tissues were detected by methylation-specific PCR (MSP) method. Methylation status of LMX1A promoter in CRC cell line MKN45 was examined by bisulfite-sequencing PCR (BSP). Expression of LMX1A in MKN45 or cells treated with increasing mount of demethylation agent, 5-aza-dC, was identified by RT-PCR. Results Aberrant methylation in primary gastric cancer was 33% (10/30). Hypermethyla-tion of LMX1A was observed in MKN45 cells. Decreased LMX1A mRNA can be restored in MKN45 after treatment with 5-aza-dC. Conclusions The frequent aberant methylation of LMX1A is observed in primary gastric cancer tissues, and decreased LMX1A in MKN45 cells is significantly correlated with promoter hypermethylation, suggesting that promoter hypermethylation of LMX1A may play an important role in tumorigenesis of gastric cancer.