Su Xing, Liu Xiaojiang, Ni Lanchun, Shi Wei, Zhu Hui, Shi Jinlong, Chen Jian, Gu Zhikai, Gao Yilu, Lan Qing, Huang Qingfeng
Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
Department of Neurosurgery, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China.
Oncol Rep. 2016 Sep;36(3):1277-84. doi: 10.3892/or.2016.4917. Epub 2016 Jul 7.
Glioblastomas are understood to evolve from brain glioma stem cells (BGSCs), and yet the biology underlying this model of tumorigenesis is largely unknown. Paired box 3 protein (Pax3) is a member of the paired box (Pax) family of transcription factors that is normally expressed during embryonic development, but has recently been implicated in tumorigenesis. The present study demonstrated that Pax3 is differentially expressed in U87MG human glioma cell, BGSC and normal 1800 human astrocyte lines. Herein, we identified that the glial fibrillary acidic protein (GFAP), a major intermediate filament protein of mature astrocytes, is directly downregulated during the differentiation of BGSCs via the binding of Pax3 to the promoter region of GFAP. Moreover, siRNA silencing of Pax3 arrested BGSC differentiation, while overexpression of Pax3 promoted the differentiation in BGSCs. Furthermore, we studied the cell proliferation, invasion, apoptosis, differentiation and expression of Pax3 and GFAP in Pax3 siRNA-knockdown and Pax3-overexpressing BGSC models by CCK-8, Transwell migration, flow cytometry and western blot assays. The results indicate that Pax3 regulates GFAP expression, and that Pax3 may contribute to the evolution of BGSCs towards malignancy.
胶质母细胞瘤被认为是由脑胶质瘤干细胞（BGSCs）演变而来的，然而这种肿瘤发生模型背后的生物学机制在很大程度上尚不清楚。配对盒3蛋白（Pax3）是配对盒（Pax）转录因子家族的成员，通常在胚胎发育过程中表达，但最近被认为与肿瘤发生有关。本研究表明，Pax3在U87MG人胶质瘤细胞、BGSCs和正常1800人星形胶质细胞系中差异表达。在此，我们发现胶质纤维酸性蛋白（GFAP）是成熟星形胶质细胞的主要中间丝蛋白，在BGSCs分化过程中，通过Pax3与GFAP启动子区域的结合而直接下调。此外，Pax3的siRNA沉默阻止了BGSCs的分化，而Pax3的过表达促进了BGSCs的分化。此外，我们通过CCK-8、Transwell迁移、流式细胞术和蛋白质印迹分析，研究了Pax3 siRNA敲低和Pax3过表达的BGSC模型中细胞增殖、侵袭、凋亡、分化以及Pax3和GFAP的表达。结果表明，Pax3调节GFAP的表达，并且Pax3可能有助于BGSCs向恶性发展。
