TMEM196基因在肺癌中的甲基化修饰与表达调控

TMEM196 gene methylation and expression in lung cancer

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-d C)处理肺癌细胞后,采用RT-PCR法检测TMEM196 m RNA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-d C)处理细胞后TMEM196 m RNA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。

OBJECTIVE： To analyze TMEM196 gene methylation and expression in lung cancer. METHODS： Methylation-specific PCR was used to detect the DNA methylation status of TMEM196 gene in normal and tumor tissues and cell lines. RT-PCR was used to analyze the expression of TMEM196 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 of TMEM196 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 of TMEM196 gene increased significantly in these cell lines. CONCLUSION： The expression of TMEM196 gene was inhibited through hypermethylation in lung cancer. This process may play an important role in lung cancer.