摘要
目的探讨胶质瘤组织中富含半胱氨酸的酸性分泌性糖蛋白(SPARC)基因甲基化状态和mRNA表达水平及两者相关性。方法2008年3月至2011年12月收集98例胶质瘤组织标本和98例正常脑组织标本(颅脑损伤患者术中切取)以及胶质瘤细胞系LN229,提取DNA和RNA,利用甲基化特异性聚合酶链反应(MSP)检测SPARC基因甲基化状态;利用实时荧光定量PCR检测SPARC基因mRNA表达水平。结果胶质瘤细胞系LN229中SPARC基因呈高度甲基化,其mRNA表达水平极低;去甲基化处理后,mRNA表达水平明显升高(P<0.01)。胶质瘤组织中SPARC基因甲基化率(70.4%,69/98)明显高于正常脑组织(21.4%,21/98;P<0.01),但其mRNA表达水平明显低于正常脑组织(P<0.01)。而且随着胶质瘤级别的增加,胶质瘤组织中SPARC基因甲基化率明显呈升高(P<0.05),但其mRNA表达水平却明显降低(P<0.01)。伴有SPARC基因甲基化的胶质瘤组织SPARC基因mRNA表达水平明显低于非甲基化胶质瘤组织(P<0.01)。然而,伴有SPARC基因启动子甲基化的胶质瘤患者生存期与非甲基化患者无统计学差异(P>0.05)。结论胶质瘤组织中SPARC基因呈高甲基化状态,其mRNA呈低水平表达;SPARC基因mRNA表达水平受其甲基化的影响;SPARC基因高甲基化可能与胶质瘤的发生相关。
Objective To explore the methylation of SPARC gene promoter and the expression level of the SPARC mRNA in malignant glioma and relationship between them. Methods The LN229 cells were cultured in DMEM with 10% fetal bovine serum for 24 hours and then treated with 5-aza-2＂-deoxytidine （5-Aza-CdR） or without. Five days later, LN229 cells were harvested. Ninety eight glioma samples （WHO grade Ⅰ , 16 cases; Ⅱ 21; Ⅲ, 32 and Ⅳ, 29） and 98 samples of normal brain tissues from 98 patients with traumatic brain injury were collected for isolating DNA and mRNA. The mRNA expression level was detected by quantitative PCR and the methylation of SPARC gene promoter was detected by methylation-specific PCR in all the samples and LN229 cells. Results There were high methylation rate of SPARC gene promoter and very low expression level of SPARC gene in LN229 cells. After 5-Aza-CdR treatment, methylation of SPARC gene promoter significantly decreased and the expression level of SPARC gene significantly increased （P〈0.01）. The methylation rate （70.4%, 69/98） of SPARC gene promoter in the glioma tissues was significantly higher than that （21.4%, 21/98） in the normal brain tissues （P〈0.01）. But the expression level of SPARC mRNA was significantly lower in the glioma tissues than that in the normal brain tissues （P〈0.01）. The methylation rate of SPARC gene promoter in the glioma tissues was significantly positively correlated with the grade of the glioma （P〈0.05）. However, there were no significant difference in the survival time between the glioma with methylation of SPARC gene promoter patients and those without methylation of SPARC gene promoter （P〉0.05）. Conclusions The high methylation of SPARC gene promoter may be one cause of SPARC mRNA expression down-regulation in the gliomas and may play an important role in the pathogenesis of the glioma, but it can not be served as a prognostic predictor in patient with glioma.
出处
《中国临床神经外科杂志》
2013年第7期418-421,共4页
Chinese Journal of Clinical Neurosurgery
