前列腺癌组织中谷胱甘肽S-转移酶P1基因启动子区域甲基化序列分析

Promoter region methylation analysis of glutathione S-transferase p1 gene in prostate carcinoma

目的:研究前列腺癌(prostate carcinoma,PCa)组织中谷胱甘肽S-转移酶P1(glutathione S-transferase P1,GSTP1)基因启动子区域CpG岛甲基化状态,探索前列腺癌早期诊断的检测方法。方法:采用巢式甲基化特异性聚合酶链反应(nest methyla-tion-specific PCR,NMSP)和基因克隆测序的方法检测31例前列腺癌组织、18例前列腺增生(benign prostatic hyperplasia,BPH)组织和3例正常前列腺(normal prostate,NP)组织中GSTP1基因启动子区域CpG岛的甲基化状态。结果:NMSP结果显示在PCa、BPH以及NP组中甲基化阳性率分别为83%、0%和0%;测序结果中PCa与BPH、NP组CG位点甲基化发生率分别为96%、34%和37%(P<0.01),BPH和NP组无统计学差异(P>0.05)。联合NMSP筛查前列腺癌明显优于单纯前列腺特异性抗原(prostate-specific antigen,PSA)检测。结论:在前列腺癌组织中GSTP1基因启动子区域CpG岛呈现超甲基化的状态,应用NMSP方法对GSTP1基因进行甲基化检测具有高灵敏度和高特异性的特点,这有望成为新的前列腺癌早期筛选和诊断的检测方法。

Objective：To investigate the promoter region CpG island methylation status of glutathione S-transferase p1（GSTP1） gene in prostate carcinoma （PCa） tissues and to search for new molecular markers for the early diagnosis of PCa. Methods： The promoter region CpG island methylation status of 31 PCa, 18 benign prostatic hyperplasia tissues （BPH） and 3 normal prostate tissues （NP） were examined by nest methylation-specific PCR （NMSP） technique, cloning and sequencing. Results： NMSP showed that the methylation rates of PCa, BPH and NP tissues were 83 %,0%0and 0 %, respectively. The CG sites methylation rates of PCa, BPH and NP tissues were 96 %,34%and 37%, respectively as determined by cloning and sequencing （P〈 0. 01）, with no significant difference found between those of BPH and NP tissues（P〉 0.05）. A combination of NMSP and prostate-specific antigen （PSA） was better than PSA alone in screen of PCa. Conclusion.. CpG islands of promoter region of GSTP1 gene is hypermethylated in PCa tissues. NMSP is sensitive and specific in detection of GSTP1 methylation,which may serve as a new method for early screen of prostate carcinoma.