Cx43基因转染胶质瘤细胞抑制细胞增殖与下调若干重要生长因子

摘要

This study was to evaluate the role of Connexin43 (Cx43) gene on the glioma cell proliferation and to explore its potential mechanism. Methods: Cx43cDNA was transfected into rat C6 glioma cells and human glioblastoma TJ905 cells deficient in endogenous Cx43 expression mediated by Lipofectamine. Cell proliferation was determined by MTT assay and average number of AgNORs (Argyrophlic nuclear organizer regions). Apoptosis was detected by TUNEL method and gap junction intercellular communication (GJIC) was evaluated with scrape loading and dye transfer method. The expression of some important growth factors and receptor relevant to the glioma development including IGF1, bFGF, PDGF, IGFBP3 and EGFR before and after transfection with CX43cDNA was compared by Western blot analyses and immunostaining. Results: Following the transfection with Cx43cDNA into glioma cells, cell proliferation was inhibited while the cell apoptosis was not increased, GJIC was significantly restored. The bFGF, PDGF, IGF1 and IGFBP3 expression of glioma cells were downregulated, whereas the expression of EGFR was not altered. Conclusion: Both the restoration of GJIC and downregulation of PDGF, bFGF, IGF1, IGFBP3 may contribute to the inhibitory effect of Cx43 on glioma cell proliferation. Cx43 can be the target for gene therapy of gliomas.%目的:研究连接蛋白43(Cx43)基因对胶质瘤细胞增殖的抑制作用及其可能的机制.方法:以脂质体介导,将Cx43cDNA转染于内源性Cx43表达缺失的鼠C6 胶质瘤细胞和人TJ905胶质母细胞瘤细胞.采用MTT法及 AgNORs(核仁组成区嗜银蛋白)平均数检测细胞增殖、 TUNEL法检测细胞凋亡、划痕标记染料示踪技术检测细胞间隙连接通讯(GJIC).应用Western 蛋白印迹及免疫组化法检测CX43cDNA转染细胞前后若干与胶质瘤发生密切相关的重要生长因子及受体表达,其中包括IGF1、bFGF、PDGF、IGFBP3、EGFR.结果:胶质瘤细胞转染Cx43cDNA后细胞增殖被抑制,细胞凋亡并未增加;GJIC明显恢复.BFGF、PDGF、IGF1、IGFBP3表达显著下调,但EGFR表达无变化.结论:Cx43基因对胶质瘤细胞增殖的抑制作用与GJIC 恢复以及bFGF,PDGF,IGF1,IGFBP3表达下调相关,CX43可望成为胶质瘤基因治疗的靶基因.