膀胱移行细胞癌组织中DcR1基因启动子区甲基化状态和蛋白表达相关性的分析

Correlation of Methylation in Promoter Region of Decoy Receptor 1 （DcR1） Gene and DcR1 Protein Expression in Transitional Cell Car- cinoma of the Bladder （TCCB）

目的检测膀胱移行细胞癌中DcR1基因启动子区甲基化状态，探讨其甲基化改变与蛋白表达关系。方法采用甲基化特异性PCR法（MSP法）检测膀胱移行细胞癌及正常膀胱粘膜组织中DcR1基因启动子区甲基化的水平。采用免疫组织化学染色法检测DcR1表达。结果37例膀胱移行细胞癌组织中．DcR1启动子区甲基化发生率为37．83％（14／37），正常膀胱粘膜组织未发现甲基化，有显著性差异（P〈0．01）。在不同分级，分期膀胱移行细胞癌组织中的差异无显著性。免疫组化显示：DcR1阳性表达率在正常组织中为100％，在肿瘤组织中为62．17％（23／37），与正常组织比较有显著性差异。14例异常甲基化的膀胱移行细胞癌组织中有11例未检测到DcR1的表达，而23例未甲基化膀胱移行细胞癌组织中有3例未检测到，二者比较有显著性差异（P〈0．01）。结论膀胱移行细胞癌组织中，DcR1基因启动子区甲基化与临床分期和病理分级无显著相关性。DcR1基因启动子区甲基化可能是其蛋白不表达的原因之一。

Objective To detect the methylation in the promoter region of decoy receptor 1 （ DcR1 ） gene in transitional cell carcinoma of the bladder （TCCB） and to examine the relationship between the aberrant methylaion of DcR1 gene and its protein expression. Methods Methylation specific PCR （MSP） was used to detect methylation in promoter region of DcR1 in TCCB and nor- mal bladder tissues. The protein expression of DcR1 was determined by immunohistochemistry. Results The incidences of methylation in promoter region of DcR1 gene of TCCB and normal bladder tissues were 37. 83% （14/37） and 0% （0/37）, respectively, and significant difference was found between the two groups （P 〈 0. 01）. There existed no correlation between the methyla- tion of DcRI and the stage or grade of TCCB. Immunohistochemical staining showed that the positive expression rate of DcR1 was 100% in the normal tissues and it was 62. 17% （23/37） in TCCB tis- sues. DcR1 protein expression was not be found in 11 out of the 14 methylated tumor tissues and 3 of the 23 unmethylated tumor tissues （P 〈 0. 01 ） . Conclusion The methylation in the promoter region of DcR1 is not correlated with the grade and stage of TCCB. But it may lead to the loss of DcR1 protein expression.