食管鳞癌组织中TIG1基因甲基化及其mRNA表达的研究

 目的：探讨他扎罗汀诱导基因1（tazarotene-induced gene-1, TIG1）基因甲基化及表达与食管鳞癌发生、发展的关系。方法：采用甲基化特异性PCR检测43例食管鳞癌组织、20例癌旁组织和15例正常组织中TIG1基因甲基化状态；实时荧光定量PCR法法检测TIG1 mRNA的表达。结果：食管鳞癌组织TIG1基因启动子甲基化率为25.6%（11/43），癌旁组织5.0%（1/20），正常组织中未检测到其甲基化，差异有统计学意义（P<0.05）；其甲基化水平与患者性别、年龄、肿瘤生长部位和分化程度无关（P>0.05），但与患者TNM分期（P<0.01）及淋巴结转移（P<0.05）有关。鳞癌组织TIG1 mRNA显著低于癌旁组织（P<0.05）及正常组织（P<0.01），甲基化组织TIGI mRNA表达显著低于非甲基化组织（P<0.01）。结论：甲基化可能是食管鳞癌中TIG1基因失活的重要机制，与患者病理分期及淋巴结转移有关。

Methylation and mRNA expression of TIG1 gene in esophageal squamous-cell carcinoma tissues

AIM: To investigate the expression and promoter methylation of tazarotene-induced gene-1 (TIG1) in esophageal squamous-cell carcinoma (ESCC) tissues. METHODS: The methods of methylation-specific PCR and real-time fluorescence quantitative PCR were applied to examine the methylation and mRNA expression of TIG1, respectively, in 43 cases of ESCC tissues, 20 cases of paracancerous tissues and 15 cases of normal tissues. RESULTS: The frequency of promoter methylation of TIG1 gene in ESCC tissues was 25.6% (11/43), which was significantly higher than that in the paracancerous tissues (5.0%, 1/20) and normal tissues (0/20). The hypermethylation of TIG1 gene in these tissues had no correlation with sex, age and clinical stage of the patients. However, it was correlated with the pathological stage (P<0.01) and lymph node metastasis (P<0.05). The mRNA expression of TIG1 in ESCC tissues was significantly lower than that in paracancerous tissues (P<0.05) and normal tissues (P<0.01). However, the expression level of TIG1 mRNA in methylated tissues was significantly lower than that in unmethylated tissues (P<0.01). CONCLUSION:  Promoter methylation may be an important mechanism of TIG1 gene inactivation in ESCC, which was related to lymph node metastasis and TNM stage of esophageal carcinoma.