中文摘要：

目的探讨胶质瘤中SLC22A18基因启动子甲基化与其表达的关系。方法选取上海交通大学医学院附属第三人民医院神经外科自2006年9月至2009年6月、武汉大学中南医院神经外科自2002年9月至2005年6月间手术切除的胶质瘤标本30例，另选10例行内减压术颅脑损伤患者的正常脑组织作为对照。采用甲基化特异性聚合酶链反应（MSP）检测标本中SLC22A18基因启动子甲基化的状态．RT—PCR和Western blotting分别检测SLC22A18 mRNA和蛋白的表达。体外培养胶质瘤U251细胞于含2μmol／L去甲基化药物5-aza-2-deoxycytidine的培养液（实验组）中，同时设普通培养液作对照，培养3、5、7d后进行细胞计数并应用Western blotting检测SLC22A18蛋白的表达。结果MSP检测结果显示15例胶质瘤组织出现甲基化．对照脑组织均表现出非甲基化；15例甲基化胶质瘤组织中SLC22A18mRNA、蛋白的表达明显低于对照脑组织。培养5、7d实验组U251细胞计数少于对照组，差异有统计学意义f氏0．05）。培养7dWestern blotting检测结果发现实验组细胞SLC22A18蛋白的表达明显高于对照组。结论观c22AJ8基因启动子甲基化导致其表达下调；去甲基化药物能恢复U251细胞SLC22A18的表达，并抑制U251细胞增殖。

英文摘要：

Objective To investigate the relationship between aberrant methylation of SLC22A 18 gene promoter and SLC22A18 expression in human glioma. Methods Thirty patients with glioma and 10 patients with craniocerebral injury performed decompression were chosen in our study; their tissue samples were prepared. Methylation-specific PCR （MSP） was used to detect the methylation status ofSLC22A18 gene promoter; and Western blotting and RT-PCR were employed to measure the protein and mRAN expressions of SLC22A18 in these tissue samples. U251 cells were cultured in vitro with demethylating agent 5-aza-2-deoxycytidine （experimental group, 2 p.moFL） and common medium （control group）, resepectively; the re-expression of SLC22A18 in U251 cells was measured by Western blotting and cell growth suppression induced by 5-aza-2-deoxycytidine was also observed 3, 5 and 7 d after the culture. Results The methlylation of SLC22A 18 gene promoter existed in glioma tissues of 15 patients （50%） but that did not exist in the tissues of patients with craniocerebral injury. The protein and mRAN expressions of SLC22A18 in the tissue samples of these 15 patients were significantly decreased as compared with those in patients with craniocerebral injury （P〈0.05）; cell counting of U251 cells in the experimental group on the 5th and 7th d of culture was significantly decreased as compared with that of those in the control group （P〈0.05）. On the 7th d of culture, Western blotting indicated that the protein b expression level of SLC22A18 in the experimental group was obviously higher than that in the control group. Conclusion The aberrant methylation of SLC22A 18 gene promoter plays a key role in down-regulating SLC22A18 expression, and demethylation agents can restore the SLC22A18 expression and suppress the growth of U251 cells.