Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
Oncol Rep. 2013 Jul;30(1):201-6. doi: 10.3892/or.2013.2456. Epub 2013 May 13.
Glioma is the leading cause of tumor-related mortality in the central nervous system. There is increasing evidence that the self-renewal capacity of cancer cells is critical for the initiation, growth and recurrence of tumors. OCT4 is a transcription factor that plays a key role in regulating the self-renewal ability of embryonic stem cells. DNA methylation is involved in the regulation of OCT4 expression during the development and differentiation of embryonic stem cells and neural stem cells. In the present study, we reported that OCT4 was highly expressed in primary gliomas and its expression levels increased in parallel with pathological grades. BSP analysis showed that the methylation levels of OCT4 gene promoter and exon were significantly reduced in comparison with the normal group and were negatively correlated with OCT4 gene expression in primary gliomas. In vitro, OCT4 gene expression was upregulated following treatment by a demethylation reagent in glioma cell lines. Our findings suggest that OCT4 is epigenetically regulated by DNA hypomethylation in primary gliomas, which may provide evidence for the role of DNA methylation in tumor and may present a new direction for developing more powerful strategies to treat glioma in the clinic.
脑胶质瘤是中枢神经系统肿瘤相关死亡的主要原因。越来越多的证据表明,癌细胞的自我更新能力对于肿瘤的发生、生长和复发至关重要。OCT4 是一种转录因子,在调控胚胎干细胞的自我更新能力方面发挥着关键作用。DNA 甲基化参与胚胎干细胞和神经干细胞发育分化过程中 OCT4 表达的调控。在本研究中,我们报道 OCT4 在原发性脑胶质瘤中高表达,其表达水平随病理分级平行升高。BSP 分析显示,与正常组相比,OCT4 基因启动子和外显子的甲基化水平显著降低,与原发性脑胶质瘤中 OCT4 基因表达呈负相关。体外实验中,去甲基化试剂处理后胶质瘤细胞系中 OCT4 基因表达上调。我们的研究结果表明,OCT4 在原发性脑胶质瘤中受 DNA 低甲基化的表观遗传调控,这可能为 DNA 甲基化在肿瘤中的作用提供证据,并为临床治疗脑胶质瘤提供更有力策略的新方向。