肺癌微卫星不稳定性与错配修复基因缺陷的相关性研究  

Relationship between microsatellite instability and deficiency of DNA mismatch repair system in lung carcinoma

作　　者：李曼[1] 喻喆[1] 李英华[1] 张晶[1] 

机构地区：[1]大连医科大学附属第二医院肿瘤内科,116011

出　　处：《肿瘤研究与临床》2011年第4期227-229,共3页Cancer Research and Clinic

基　　金：大连市自然科学基金（2007E21SF216）;辽宁省教育厅科研项目（20060205）

摘　　要：目的通过对肺癌微卫星不稳定性（MSI）的分析与错配修复基因蛋白表达的检测，探讨肺癌发病的分子机制。方法从50例肺癌患者的正常肺组织、癌组织中提取DNA；SSCP法检测标本中MSI发生情况；免疫组织化学法检测错配修复基因hMLHl及hMSH2在肺癌中的表达情况。结果50例肺癌中微卫星高度不稳定（MSI-H）14例，低度不稳定（MSI-I）21例，稳定（MSS）15例，正常组织中未出现MSI，两者之间差异有统计学意义（P=0．000）；免疫组化结果显示hMLHl在MSI肺癌组织中常为缺失表达，表达率为74％（37／50）；hMSH2在MSI肺癌组织中也呈缺失表达，表达率为32％（16／50）；而在MSS肺癌组织中均显示hMLHl、hMSH2基因蛋白表达阳性。结论肺癌的发生可能存在MSI途径，而hMLH1、hMSH2的表达失活则可能导致MSI的发生，因此，MSI可作为肺癌诊断的指标之一。Objective To investigate the relationship between microsatellite instability （MSI） and mismatch repair gene （MMR） in lung carcinoma, and to analyze its action in lung carcinogenesis. Methods DNA was extracted from 50 cases of lung carcinoma and adjacent normal tissue. SSCP was used to detect MSI. lmmunohistochemistry was performed to measure the expression of hMLH1 and hMSH2 protein in lung carcinoma. Results Of the 50 cases of lung carcinoma,14 with high MSI, 21 with low MSI, and 15 with microsatellite stability, 0 with MSI in normal group （P = 0.000）. Lack of hMLH1 and hMLH2 staining was found in 37 of 50 （74 %） and 16 of 50 （32 %） lung carcinoma tissues with MSI, respectively; but both of hMLHI and hMSH2 positive staining was found in the lung carcinoma tissues with MSS. Conclusion MSI appears to he associated with lung carcinogenesis, and inactivation of either hMLH1 or hMSH2 may be responsible for MSI, suggesting that MSI may become one of diagnosis indexes of lung carcinoma.

关 键 词：DNA错配修复 微卫星不稳定性 肺肿瘤 

分 类 号：R734.2[医药卫生—肿瘤]