单胺氧化酶抑制剂诱导胶质瘤细胞的体外分化

Effect of Monoamine Oxidase Inhibitor on the Differentiation of Malignant Glioma Cell

为研究单胺氧化酶抑制剂(TCP)对体外培养的人脑胶质瘤U251细胞的诱导分化作用,以不同浓度TCP单独或与100nmol/L组蛋白去乙酰化酶抑制剂(TSA)联合处理U251细胞。采用倒置显微镜观察细胞形态学变化;噻唑蓝(MTT)比色法检测细胞增殖变化;流式细胞仪检测细胞周期变化;Hoechst 33258染色显示细胞凋亡;Real-time PCR和Western印迹法检测分化相关基因mRNA和蛋白表达水平的改变。结果表明:TCP可诱导细胞突起增多且变细长,抑制细胞增殖,阻滞细胞周期于G1期,抑制全能性转录因子Oct4和Sox2的表达,上调分化标志基因胶质纤维酸性蛋白(GFAP)的表达,TCP联合TSA也诱导了GFAP的高表达。这些结果提示:TCP可诱导胶质瘤U251细胞分化,TSA对TCP诱导细胞分化有协同作用。

To investigate the effect of monoamine oxidase inhibitor tranylcypromine （TCP） on the differentiation of human U251 glioma cells, we treated U251 cells with TCP and/or 100 nmol/L histone deacetylase inhibitor trychos- tatin A （TSA）. The differentiation of U251 cells was observed with inverted microscopy. The cell proliferation and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Apoptosis was observed by Hoechst 33258 staining. The levels of differentiation-related genes were assessed by real-time PCR and Western blot- ting. TCP-induced differentiation was characterized by typical morphological changes, inhibition of cellular prolifera- tion, accumulation of cells in the G1 phase of the cell cycle, decreased expression of the pluripoteney transcription factors Oct4 and Sox2, and increased expression of glial fibrillary acid protein （GFAP）, The combination of TCP and TSA treatment also triggered an over-expression of GFAP. These findings suggest that TCP may induce differentiation of U251 glioma eells, and the differentiation process may be promoted by histone deaeetylase inhibitor TSA.