PTEN基因甲基化及其表达与非小细胞肺癌侵袭转移的关系

The correlation between promoter region methylation as well as mRNA expression of PTEN gene and invasion as well as metastasis of non-small-cell lung cancer

目的观察非小细胞肺癌组织中第10号染色体缺失的张力蛋白同源的磷酸酶基因(phosphatase and tensin homology deleted on chromosome ten,PTEN)mRNA表达和启动子区甲基化状态变化,探讨其与肺癌临床病理特征的关系。方法采用RT-PCR和甲基化特异性PCR法(MSP)分析肺癌及相应癌旁肺组织中PTEN基因表达情况及其启动子区甲基化状态。结果肺癌组织中PTEN基因启动子区甲基化率为57.8%(48/83),明显高于癌旁肺组织的30.1%(25/83)(P<0.05)。肺癌组织中PTENmRNA的阳性率为32.5%(27/83),明显低于癌旁肺组织的55.4%(46/83)(P<0.05);PTEN基因启动子甲基化与mRNA的表达与NSCLC的分化程度、TNM分期、淋巴结转移及术后生存时间有明显关系,PTEN甲基化状态与mRNA表达呈负相关(P<0.05)。结论肺癌组织中PTEN基因失表达与其启动子区甲基化有关,这可能是肺癌发生发展以及转移的原因之一。

Objective To detect the mRNA expression and promoter region methylation of phosphatase and tensin homology deleted on chromosome ten （PTEN） in non-small cell lung cancer and to explore their relationship with clinicopathologieal characteristics. Methods The mRNA expression and promoter region methylation condition of PTEN were detected by RT-PCR and methylation- specific PCR （MSP） in lung cancer tissues and cancer adjacent tissues. Results The methylation rate was 57.8% （48/83） in PTEN gene promoter region of lung cancer tissues, which was significantly higher than that [30. 1% （25/83）] in cancer adjacent tissues （ P 〈 0.05 ）. The positive rate of expression of PTEN mRNA was 32.5 % （27/83） in lung cancer tissues, which was significantly lower than that [55.4% （46/83） ] in cancer adjacent tissues （ P 〈0.05）. The PTEN gene promoter methylation was closely correlated with mRNA expression, differentiation degree of NSCLC, TNM staging,lymph node metastasis and patient＇ s survival time after operation, and PTEN methylation state was negatively related to the expression of mRNA （ P 〈 0.05）. Conclusion The loss of PTEN mRNA expression is associated with methylation in promoter region, which may be one of causes of carcinogenesis and metastasis of lung cancer.