前列腺癌相关基因PAX5启动子甲基化的临床意义

目的：探讨PAX5基因启动子甲基化作为前列腺癌生物标志物的临床价值。 方法：采用Real time RT-PCR检测前列腺细胞系（RWPE-1、LNCaP、PC-3、DU145）中PAX5 mRNA的表达，甲基化特异性PCR(MSP)法分析4株前列腺细胞的甲基化状态；去甲基化药物处理后，Real time RT-PCR法检测肿瘤细胞PAX5基因mRNA表达； Real time MSP法检测64例前列腺癌患者、22例前列腺增生患者与47例健康体检者血清中PAX5基因启动子甲基化水平，并统计分析血清PAX5基因启动子甲基化水平与临床病理参数的相关性；运用ROC曲线分析PAX5基因启动子甲基化在前列腺癌诊断中的价值。结果：Real time RT-PCR结果显示，与正常前列腺上皮细胞RWPE-1相比，PAX5 mRNA在3株前列腺癌细胞中均表达下调；LNCaP、PC-3、DU145前列腺癌细胞均可检测到PAX5基因启动子甲基化，而正常前列腺上皮细胞RWPE-1不存在PAX5基因启动子甲基化；去甲基化药物可恢复PAX5基因mRNA表达；Real time MSP结果显示，前列腺癌患者的血清PAX5基因启动子甲基化水平显著高于前列腺增生患者和健康体检者；前列腺癌患者的血清PAX5基因启动子甲基化率与Gleason评分和TNM分期有关；ROC结果显示PAX5基因的诊断价值优于PSA。结论：本研究结果提示启动子甲基化是前列腺癌细胞中PAX5基因表达下调的主要原因，血清PAX5启动子甲基化是一种潜在的前列腺癌诊断标志物。

Clinical significance of promoter methylation of prostate cancer related gene PAX5

Objective: To investigate the clinical value of PAX5 promoter methylation as a biomarker of prostate cancer. Methods: The expression of PAX5 mRNA in prostate cell lines (RWPE-1, LNCaP, PC-3, DU145) was detected by real time RT-PCR. Methylation-specific PCR (MSP) was used to analyze the methylation status of four prostate cells Real-time RT-PCR was used to detect the expression of PAX5 mRNA in tumor cells. Real time MSP was used to detect the expression of PAX5 gene in 64 cases of prostate cancer, 22 cases of benign prostatic hyperplasia and 47 healthy controls. The methylation level of PAX5 gene promoter in the serum of patients with prostate cancer was analyzed by ROC curve. The methylation level of PAX5 gene promoter in the serum of patients with prostate cancer was analyzed statistically. Results: Real time RT-PCR showed that PAX5 mRNA was down-regulated in three prostate cancer cells compared with normal prostate epithelial cell RWPE-1; PAX5 gene promoter was detected in LNCaP, PC-3 and DU145 prostate cancer cells Methylation of PAX5 gene promoter in normal prostate epithelial cell RWPE-1; the expression of PAX5 gene mRNA was restored by demethylation drug; Real time MSP result showed that the serum PAX5 gene promoter of prostate cancer patient Methylation level of PAX5 gene promoter was significantly higher than that of benign prostatic hyperplasia patients and healthy subjects. The methylation rate of PAX5 gene promoter was correlated with Gleason score and TNM staging; ROC results showed that the diagnostic value of PAX5 gene was superior to that of PSA. Conclusion: The methylation status of PAX5 gene in prostate cancer cells is the main reason for the down-regulation of PAX5 gene expression. Methylation of PAX5 promoter is a potential marker for diagnosis and prognosis of prostate cancer.