胶质瘤IDH1基因突变与胶质瘤干细胞相关基因表达的相关性研究

Correlation between mutations of glioma isocitrate dehydrogenase 1 gene and expression of glioma stem cell-related gene

目的研究原发性、原位复发性胶质瘤中异柠檬酸脱氢酶1（IDHI）基因突变情况，分析胶质瘤干细胞相关基因的变化情况与IDH1基因突变的相关性。方法选取新疆自治区人民医院神经外科自2010年8月至2011年8月间手术切除并经病理证实的人脑胶质瘤标本43例．其中原发30例，复发13例，应用PCR检测标本中IDH1基因多态性，流式细胞术检测肿瘤组织中CD133、nestin的表达。结果基因测序显示原发胶质瘤中17例（56．67％1发生IDHl突变，复发胶质瘤中13例（53．85％）发生IDH1突变，突变类型均为R132H型。流式细胞仪检测显示原发、复发胶质瘤标本中nestin、CD133的阳性表达率与肿瘤的病理分级均成正相关关系（P〈0．05）。伴IDH1突变的胶质瘤标本nestin、CD133阳性表达率较IDH1野生型胶质瘤增多，差异有统计学意义（P〈0．05）。与原发肿瘤比较，复发肿瘤中nestin、CD133阳性细胞表达率明显增高，差异有统计学意义（P〈0．05）。结论IDHl突变在原发、复发性胶质瘤中发生频率均很高．可上调干细胞相关基因Nestin和CD133 的表达。复发肿瘤中升高的干细胞相关基因与肿瘤发生及复发密切相关。

Objective To study the distribution of isocitrate dehydrogenase （IDH1） gene mutations in primary and recurrent gliomas, and their correlation with expression of glioma stem cell-related gene. Methods Forty-three human glioma specimens, collected during the resection in our hospital from August 2010 to August 2011 and confirmed by pathology, were chosen, including 30 having primary gliomas and 13 having recurrent gliomas. The polymorphisms of 1DH1 gene were detected by real-time quantitative PCR; the protein expression levels of nestin and CD133 were measured by flow cytometry. Results Gene sequencing indicated that 1DH1 gene mutations were observed in 17 specimens having primary gliomas （56.67%） and 7 specimens having recurrent gliomas （53.85%）; and the mutation appeared as R132H type. The expressions of CD133-positive cells and nestin-positive cells had significantly positive correlation with the grade of glioma malignancy in both primary and recurrent glioma groups （P〈0.05）. And the proportion of CD133-positive cells and nestin-positive cells of primary and recurrent glioma groups having mutations was obviously higher than that of cells of primary and recurrent glioma groups with IDH1 wild type （P〈0.05）. As compared with those in primary gliomas, the expressions of CD133-positive and nestin-positive cells in recurrent gliomas were significantly increased （P〈0.05）. Conclusion IDH1 gene mutations occur frequently in primary and recurrent gliomas; IDH1 gene mutations have significant correlation with increased expression of nestin and CD133; and the increment of glioma stem cell-related gene has a close relation with tumorigenesis and tumor recurrence.