中文摘要：

目的：检测4种人脑成胶质细胞瘤细胞株中成视网膜细胞瘤蛋白结合锌指结构基因1（retinoblastoma protein-interacting zinc finger gene1,RIZ1）基因启动子区的甲基化状态,进一步认识RIZ1在胶质瘤发病机制中的作用。方法：应用甲基化特异性PCR法（methylation specific PCR,MSP）检测4种人脑成胶质细胞瘤细胞株U87、U251、A172和T98中RIZ1基因启动子区的甲基化水平,其中U87细胞发生甲基化,被选为后续实验对象。RT-PCR检测U87细胞经5-Aza-CdR处理前后RIZ1 mRNA表达量的变化,MTT检测5-Aza-CdR对U87细胞生长增殖的影响。结果：4种人脑成胶质细胞瘤细胞株中U87和U251细胞中检测到RIZ1基因启动子区域发生甲基化;U87细胞经5-Aza-CdR处理后其RIZ1 mRNA的表达量上调;MTT法检测显示5-Aza-CdR能抑制U87的生长增殖,且与5-Aza-CdR的浓度和作用时间呈负相关。结论：RIZ1基因启动子高甲基化是人脑成胶质细胞瘤细胞株中RIZ1基因表达下调的重要机制。

英文摘要：

Objective： To investigate the methylation status in the promoter region of the retinoblastoma protein-interacting zinc finger1（ RIZ1） gene in four human glioblastoma（ GBM） cell lines as well as the influence of methyltransferase inhibitor 5-Aza-CdR on RIZ1 gene transcription and proliferation in GBM cells with a hypermethylated RIZ1 promoter. Methods： The methylation status in the promoter region of RIZ1 in four human GBM cell lines,U87,U251,A172 and T98,were analyzed by methylation-specific polymerase chain reaction. The cell line with RIZ1 promoter hypermethylation was treated with 5-Aza-Cdr. In the treated cells,RIZ1 mRNA was assessed by real-time PCR and viability by MTT assays. Results： Promoter methylation of the RIZ1 gene was detected in GBM cell lines U87 and U251. The abundance of RIZ1 mRNA was significantly increased in U87 after treatment with 5-Aza-CdR. Treatment of U87 cells with 5-Aza-CdR resulted in a time- and concentration-dependent proliferation inhibition. Conclusions： Promoter methylation may play an important role in the epigenetic silencing of RIZ1 gene expression in human GBM cells.