肺癌患者MPDZ基因异常甲基化的研究

目的:探讨肺癌组织以及相应的外周血浆和痰液中MPDZ基因异常甲基化的情况,以及其在肺癌诊断中的作用。方法:采用甲基化特异性PCR(MSP)方法检测49例肺癌组织、20例癌旁正常组织以及相应的外周血浆和痰液中MPDZ基因甲基化发生情况。结果:49例肺癌组织中MPDZ基因甲基化发生率为67%(33/49),癌旁正常组织中的MPDZ基因甲基化发生率为0(0/20)(P=0.00)。MPDZ基因甲基化检出率与临床分期相关(P=0.039),但与患者的年龄、性别、是否吸烟、肿瘤的分化程度以及肿瘤的病理分类无显著相关(P>0.05)。33例癌组织MPDZ基因发生了甲基化的肺癌患者相应血浆的DNA标本中有25例发生了甲基化,甲基化检出率为76%(25/33);痰液标本中有18例发生了甲基化,甲基化检出率为55%(18/33)。16例癌组织MPDZ基因未甲基化的肺癌患者其对应的血浆和痰液标本未检出该基因甲基化。提示痰液和血浆标本中MPDZ基因甲基化能较好地反映肿瘤组织中该基因的甲基化状况。结论:MPDZ基因在肺癌患者的癌组织中、血浆中及痰液中均有较高比例甲基化检出率,提示MPDZ基因甲基化可能在肺癌的诊断中具有一定的价值。

DNA hypermethylation status of MPDZ gene in lung cancer

OBJECTIVE: To study MPDZ gene hypermethylation in lung cancer tissue,peripheral plasma and sputum,and to explore its relationship with clinicopathologic features. METHODS: Methylation specific PCR was used to detect the methylation of MPDZ gene in 49 cases of lung cancer tissue,20 cases of normal tissue and corresponding blood plasma and sputum samples. RESULTS: The frequency of methylation of MPDZ gene promoter was 67%(33/49) in lung cancer tissues,but not in normal tissues 0(0/20)(P=0.00). The methylation of MPDZ gene was significantly correlated with clinic stages of lung cancer patients(P=0.039),but not correlated with patient's age,sex,smoking,tumor differentiation and pathological classification(P>0.05). In 33 patients with MPDZ hypermethylation in tumor tissue,the same aberrant methylation was detected in 25(76%) of the corresponding plasma and 18(55%) of sputum samples,whereas hypermethylation of MPDZ was not found in the sputum and plasma from the patients with MPDZ unmethylation in tumor sample. CONCLUSION: MPDZ gene has highly methylated in lung cancer tissue,corresponding blood plasma and sputum. The methylation of MPDZ gene may have a certain value in the diagnosis of lung cancer.