钙结合蛋白S100A4通过TLR4/NF-κB信号通路调控胶质瘤细胞增殖、存活及迁移功能

Calcium-binding protein S100A4 regulates glioma cell proliferation,survival and migration functions through TLR4/NF-κB signaling pathway

目的:探索外源性钙结合蛋白S100A4对胶质瘤细胞增殖、存活及迁移功能的影响及机制。方法:利用UCSC数据库下载泛癌数据集,进行S100A4在泛癌中的表达及预后分析;从CGGA数据库中下载胶质瘤患者的转录组数据和临床数据,利用R软件进行分析S100A4表达在胶质瘤患者中的预后与进展;利用在线分析工具GEPIA与STRING进行胶质瘤患者的S100A4蛋白质网络互作分析。体外培养人胶质瘤细胞系(U87与U251),实验分为3组:PBS组、S100A4组、S100A4+TAK242组[瑞沙托维(TAK242)为Toll-样受体4(TLR4)特异性抑制剂]。流式细胞术检测胶质瘤细胞的增殖与凋亡;细胞划痕实验、Transwell实验及克隆形成实验检测U87与U251细胞的迁移及增殖能力;Western blot检测TLR4蛋白、NF-κB相关信号分子蛋白水平。结果:生物信息学结果显示,S100A4在多种肿瘤中显著上调(P<0.05),包括:胶质母细胞瘤(GBM)、低级胶质瘤(LGG)、胃癌(STAD)、肝细胞肝癌(LIHC)等,其中在GBM和LGG中预后较差。与低表达S1004的胶质瘤患者相比,高表达S100A4的胶质瘤患者生存期更短,WHO分级程度更高。此外,胶质瘤患者S100A4蛋白可能与膜联蛋白A2(ANXA2)、TLR4和晚期糖基化终末产物特异性受体(AGER)蛋白存在相互作用。细胞实验中,与PBS组相比,外源性S100A4处理后,胶质瘤U87和U251细胞增殖、迁移能力增强,TLR4、p-ERK1/2、p-p38、p-p65蛋白水平显著上调(P<0.05)。与S100A4组相比,S100A4+TAK242组胶质瘤细胞增殖、迁移能力减弱,TLR4、p-ERK1/2、p-p38、p-p65蛋白水平显著下调(P<0.05)。结论:S100A4可能通过TLR-4/NF-κB信号通路调控胶质瘤细胞增殖、迁移及存活功能。

Objective:To investigate the effects and mechanisms of exogenous calcium-binding protein S100A4 on proliferation,survival and migration functions of glioma cells.Methods:Pan-cancer dataset was downloaded from UCSC database for the analysis of S100A4 expression and prognosis in pan-cancer,and transcriptome and clinical data of glioma patients were downloaded from CGGA database.Prognosis and progression of S100A4 expression in glioma patients were analyzed by R software.S100A4 protein network interaction of glioma patients were addressed by online analytical tools GEPIA and STRING.Human glioma cell lines(U87 and U251)were cultured in vitro,and the experiment was divided into 3 groups:PBS group,S100A4 group and S100A4+TAK242 group[Resatorvid(TAK242)was a specific inhibitor of Toll-like receptors 4(TLR4)].Flow cytometry was used to detect proliferation and apoptosis of glioma cells.Wound healing assay,Transwell assay and clone formation assay were used to detect migration and proliferation ability of U87 and U251 cells,and Western blot was used to detect levels of TLR4 protein and NF-κB related signaling proteins.Results:Bioinformatics results showed that S100A4 was significantly upregulated in multiple tumours(P<0.05),which included glioblastoma(GBM),lower grade glioma(LGG),stomach adenocarcinoma(STAD),liver hepatocellular carcinoma(LIHC),etc,with poorer prognosis in GBM and LGG.Compared with glioma patients with low expression of S1004,high expression S100A4 in glioma patients had shorter survival and higher degree of WHO classification.In addition,S100A4 protein in glioma patients may interact with Annexin A2(ANXA2),TLR4 and advanced glycosylation end product-specific receptor(AGER)proteins.In cellular experiments,U87 and U251 cells showed enhanced proliferation and migration,and significantly up-regulated levels of TLR4,p-ERK1/2,p-p38 and p-p65 proteins after exogenous S100A4 treatment compared to PBS group(P<0.05),while glioma cells in S100A4+TAK242 group showed weaker proliferation and migration,and lower TLR4,p-p38 and p-p65 protein levels than those in S100A4 group,TLR4,p-ERK1/2,p-p38,p-p65 protein levels were significantly down-regulated(P<0.05).Conclusion:S100A4 may regulate function of glioma proliferation,migration and survival through TLR4/NF-κB signaling pathway.