膀胱癌中eya4基因启动子区甲基化状态及其临床意义

The methylation status and clinical significance of the promoter of eya4 gene in bladder cancer

目的探讨膀胱癌细胞系和膀胱移行细胞癌组织中EYA转录共激活磷酸酶4(eya4)基因启动子区CpG岛甲基化状态及在临床病理特征中的意义。方法应用甲基化特异性聚合酶链反应(MSP)检测eya4基因在5株膀胱癌细胞系、1株膀胱永生化上皮细胞系和75例膀胱移行细胞癌组织及癌旁组织,并结合临床病理特征行统计学分析。结果eya4基因启动子区在5株膀胱癌细胞系中,有4株出现甲基化,其甲基化率为80%;在人正常膀胱细胞系中甲基化阴性。eya4在膀胱癌组织中的甲基化率为70.7%(53/75),显著高于癌旁组织(24%,18/75),差异有统计学意义(χ~2=32.760,P<0.01)。eya4基因启动子区CpG岛甲基化在临床病理特征中如单发膀胱肿瘤与多发膀胱肿瘤相比,直径≤3 cm的膀胱肿瘤与>3 cm的膀胱肿瘤相比,低级别膀胱肿瘤与高级别膀胱肿瘤相比,浅表性膀胱肿瘤与浸润性膀胱肿瘤相比,差异均有统计学意义(P<0.05),但与年龄和性别无关。结论基因eya4启动子区甲基化与膀胱癌的发生发展有关,可能作为膀胱移行细胞癌诊断的一个新的标志物。

Objective To explore the methylation status of the CpG island of eyes absent 4 （eya4） promoter and its significance of clinical pathological characteristics in bladder cancer. Methods The promoter methylation status of eya4 gene was examined by methylation specific PCR（MSP） in 5 bladder cancer cell lines and 75 cases of primary bladder transitional cell carcinoma. 1 bladder immortalized epithelial cell line and 75 cases of corresponding adja- cent tissues were selected as controls. Meanwhile, clinical pathological data of patients were investigated by statisti- cal analysis. Results The promoter of eya4 were detected in 4 cases of 5 bladder cancer cell lines where methyla- tion rate was 80%. While the methylation status was negtive in normal bladder epithelial cell line. The methyla-tion rate of eya4 gene was 70.7% in bladder cancer tissues（53/75） which was significantly more frequent than ad- jacent tissues（24%, 18/75 ）, and the dift^rence was significant （ X2 = 32. 760, P 〈 0.01 ）. The methylation status of the CpG island of eya4 promoter was correlated with the clinicopathological features such as tumor diameter, tumor single and mutiple, tumor grade and stage （ P 〈 0.05 ）. However, no association was detected between eya4 methylation and age and gender. Conclusion eya4 methylation status which is closely correlated with the occur- rence and development of primary bladder transitional cell carcinoma may be used as an independent diagnostic bio- marker for patients with different kind of bladder cancer.