目的：检测miR-129成熟体miR-129-5p在人脑胶质瘤组织中的表达特点，探讨人脑胶质瘤组织中miR-129-2表达异常是否与miR-129-2启动子甲基化有关。方法：收集湘雅医院神经外科2013年10-12月收治的胶质瘤患者肿瘤组织21例、脑外伤患者非肿瘤脑组织标本21例。Real-time PCR检测脑胶质瘤组织和非肿瘤脑组织、脑胶质瘤细胞株和正常脑胶质细胞株中miR-129-5p的表达；甲基化特异性PCR（methylation-specific PCR，MSP）检测胶质瘤组织中miR-129-2基因启动子甲基化的情况；亚硫酸氢盐硫化测序PCR（bisulfite-sequencing PCR，BSP）分析经甲基化转移酶抑制剂5-氮杂-2′-脱氧胞苷（5-aza-2′-deoxycitydine，5-Aza-dC）处理后的胶质瘤细胞miR-129-2基因启动子甲基化水平的变化，同时Real-time PCR检测miR-129-5p的表达变化。结果： miR-129-5p在人脑胶质瘤组织和细胞中表达显著低于非肿瘤脑组织和正常脑胶质细胞（P<005），胶质瘤组织中miR-129-2基因的启动子甲基化率显著高于正常脑组织（P<0.05），使用5-Aza-dC去甲基化处理脑胶质瘤细胞后miR-129-2基因的启动子甲基化程度降低、miR-129-5p表达显著升高（P<0.05）。结论： miR-129-5p在脑胶质瘤中显著低表达，miR-129-2启动子甲基化是导致其低表达的机制之一。

Objective:To explore the expression characteristics of miR-129-5p (matured miR-129) in human glioma tissues, and to investigate whether the abnormal expression of miR-129-5p in human glioma tissues is related to methylation of its promoter. Methods: Twenty one tumor tissue specimens and twenty one non-tumor tissue specimens were respectively collected from patients with glioma and patients with brain trauma, who underwent surgery in Department of Neurosurgery, Xiangya Hospital during October to December, 2013. Expressions of miR-129-5 in human glioma tissues, nontumor brain tissues, glioma cell lines and normal glial cell lines were measured with Real-time PCR.Promoter methylation of miR-129-2 gene in glioma tissues was examined by methylation-specific PCR (MSP). Changes of promoter methylation level of miR-129-2 gene in the glioma tissues after treatment of methylation transferase inhibitor 5-aza-2′-deoxycitydine (5-Aza-dC) were analyzed with bisulfite-sequencing PCR (BSP). Results: The expressions of miR-129-5p in human giloma tissues and cells were significantly lower than those in normal brain tissues and cells (P<0.05). The promoter methylation rates of miR-129-2 gene in glioma tissues were significantly higher than those in normal brain tissues (P<0.05). After treatment of demethylation with 5-Aza-dC, the promoter methylation of miR-129-2 gene decreased and the expression of miR-129-5p significantly increased (P<0.05). Conclusion: miR-129-5p is significantly down-expressed in human giloma, promoter methylation of miR-129-2 is one of the mechanisms which result in low expression of miR-129-2 in human glioma.

湖南省教育厅课题资助项目（No. 13C571）