TMEM196基因在肺癌中的甲基化修饰与表达调控

目的:分析TMEM196基因在肺癌组织中的甲基化情况以及甲基化发生对TMEM196基因表达的影响。方法:采用MSP方法检测肺癌组织、癌旁正常对照组织及肺癌细胞株TMEM196基因甲基化率;用去甲基化药物5-氮-2'-脱氧胞苷(5-aza-dC)处理肺癌细胞后,采用RT-PCR法检测TMEM196 mRNA表达水平。 结果:肺癌组织中TMEM196基因甲基化发生率为57%(28/49),而正常对照组织中该基因甲基化发生率为0(0/20)。TMEM196基因甲基化与肿瘤的分化程度(P=0.012)和临床分期显著相关(P=0.007),而与患者的年龄、性别、吸烟以及肿瘤的病理分类无显著相关(P>0.05)。TMEM196基因在肺癌细胞株H1975和H1650中高甲基化且表达缺失,去甲基化药物(5-aza-dC)处理细胞后TMEM196 mRNA表达明显升高,说明TMEM196基因表达可能受甲基化调控。结论:TMEM196基因甲基化与肺癌的发生发展密切相关,推测该基因通过DNA甲基化失活参与了肿瘤的发生。

TMEM196 gene methylation and expression in lung cancer

OBJECTIVE:To analyzeTMEM196 gene methylation and expression in lung cancer.METHODS:Methylation-specific PCR was used to detect the DNA methylation status ofTMEM196 gene in normal and tumor tissues and cell lines. RT-PCR was used to analyze the expression ofTMEM196 gene in tumor cells and also in 5-aza-dC-treated tumor cells.RESULTS:The hypermethylation of TMEM196 was detected in lung cancer tissues (57%, 28/49),but not in normal tissues (0,0/20). Methylation ofTMEM196 gene was significantly correlated with tumor differentiation (P=0.012) and the clinical stages of lung cancer patients (P=0.007),but not correlated with the patient's age,sex, smoking,and pathological classification (P>0.05). TMEM196 showed hypermethylation and its expression decreased in lung cancer cell lines H1975 and H1650. After treatment with demethylation drug,expression ofTMEM196 gene increased significantly in these cell lines. CONCLUSION:The expression ofTMEM196 gene was inhibited through hypermethylation in lung cancer. This p rocess may play an important role in lung cancer.