甲硫腺苷磷酸化酶基因在非小细胞肺癌中的转录表达及临床意义

Expression and clinical significance of methylthioadenosine phosphorylase gene in patients with non-small cell lung cancer

目的 探讨甲硫腺苷磷酸化酶 (MTAP)基因在非小细胞肺癌中的转录表达变化情况及其临床意义。方法 采用逆转录聚合酶链反应 (RT PCR)方法检测了 15例新鲜肺癌标本及相应癌旁组织中MTAPmRNA的表达情况。同时运用Western印迹法检测了MTAP蛋白质的表达情况。结果 MTAP在 73 3% ( 11/ 15 )的肿瘤标本中不表达或转录水平降低 ,而MTAP在癌旁对照组织中的表达率却高达 93 3% ( 14 / 15 ) ;对于 11例RT PCR分析认定低表达或不表达的样本 ,再通过Western印迹方法进一步验证 ,发现与RT PCR结果一致。另外 ,MTAP在肺腺癌和鳞癌中低表达现象差异无显著意义 ,但在中 /低分化肺癌中的低表达与高分化癌相比增高 ,差异有显著意义。

Objective To investigate the change of expression of methylthioadenosine phosphorylase (MTAP) gene in patients with non small cell lung cancer and its clinical significance.Methods Thirty fresh samples of cancer with adjacent tissues were collected from 15 patients with lung cancer, 12 males and 8 females, aged 53 6 (38～72), 8 with squamous cell carcinoma and 7 with adenocarcinoma. The expressions of MTAP mRNA and of its protein were analyzed by RT PCR and Western blotting.Results In 11 out of the 15 tumor samples (73 3%) MTAP mRNA was not expressed or expressed only after the additional 5 circulations. However, the MTAP mRNA expression rate was 93 3% (14/15) in the adjacent tissues. The result in the 11 samples with none or low MTAP mRNA expression was confirmed by Western blot analysis. The low expression rates were not significantly different between lung adenocarcinoma and squamous cell carcinoma. But the low expression rate of MTAP in intermediate and poorly differentiated lung cancer was significantly higher than that in well differentiated cancer. Conclusion The low expression or loss of MTAP gene may be relevant closely to the differentiation degree in lung cancer.