基于生物信息学探讨IFIH1和SAMD9L在胶质母细胞瘤抗肿瘤免疫中的作用

The role of IFIH1 and SAMD9L in anti-tumor immunity of glioblastoma based on bioinformatics

目的通过生物信息学数据库筛选及分析,并结合临床验证,探讨胶质母细胞瘤(GBM)的基因表达变化及其可能的作用机制。方法在GEO数据库检索GBM基因数据集,通过GEO2R在线工具处理,将各数据集的基因进行韦恩图分析,筛选出差异基因(DEGs)。利用String网站构建DEGs蛋白互作(PPI)网络图,并进行功能富集分析;采用Cytoscape软件MCODE插件识别PPI网络中的关键模块、CytoHubba插件筛选PPI网络中的Hub基因。在GEPIA网站观察Hub基因的表达水平及其对生存率的影响。以2017年6月至2019年12月经手术切除且病理证实的GBM患者40例为研究组,15例正常人为对照组。采用ELISA法检测两组血清干扰素β(IFN-β)、趋化因子C-X-C配体10(CXCL10)、干扰素诱导蛋白44样(IFI44L)和肿瘤坏死因子-α(TNF-α)含量;采用实时荧光定量PCR测定GBM组织及瘤周正常组织中的基因表达水平,并对其进行相关性分析。结果纳入GSE2223、GSE4290及GSE15824三个数据集,筛选出83个DEGs。共识别出8个Hub基因,其中IFIH1和SAMD9L对患者生存率有潜在影响,且两者呈正相关(r=0.86,P<0.001)。GBM患者血清IFN-β、CXCL10、IFI44L和TNF-α含量均高于对照组(P<0.001)。GBM组织中SAMD9L表达量明显高于瘤周正常组织(6.00±2.98 vs.1.06±0.49,P<0.001),IFIH1表达量亦明显高于瘤周正常组织(4.05±1.90 vs.1.01±0.57,P<0.001),且GBM组织中IFIH1和SAMD9L表达量呈正相关(r=0.663,P<0.001);IFIH1、SAMD9L基因表达与血清IFN-β、CXCL10、IFI44L含量均呈正相关(P均<0.05)。IFIH1、SAMD9L高表达组的中位OS分别为16.5个月、17个月,均低于低表达组(P<0.05)。结论GBM患者IFIH1和SAMD9L基因表达上调且存在相关性,并降低了生存率;两者与机体抗肿瘤免疫系统激活密切相关,可能是免疫治疗GBM的新靶点。

Objective To explore the gene expression changes of glioblastoma(GBM)and its possible mechanism by screening and analyzing of bioinformatics database,combined with clinical verification.Methods The GBM gene datasets was searched in the GEO database,processed by the GEO2R online tool,and the genes in each dataset were analyzed by the Venn diagram to select the differential genes(DEGs).The String website was used to construct a DEGs protein interaction(PPI)network and perform function enrichment analysis.The plug-in MCODE of Cytoscape software was used to identify the notable modules in the PPI network,and the CytoHubba plug-in to screen the Hub genes in the PPI network.The expression level of Hub gene and its effect on survival rate were observed on the GEPIA website.From June 2017 to December 2019,40 patients with GBM who were surgically removed and pathologically confirmed were selected as the study group,and 15 normal people as the control group.ELISA method was used to detect the levels of serum interferonβ(IFN-β),chemokine C-X-C ligand 10(CXCL10),interferon inducible 44 like(IFI44L)and tumor necrosis factor-α(TNF-α).The real-time fluorescent quantitative PCR method was used to determine gene expression levels in GBM tissues and normal tissues around tumors,and the correlation between them was performed.Results GSE2223,GSE4290 and GSE15824 gene datasets were included,and 83 DEGs were screened out.A total of 8 Hub genes were identified,in which the IFIH1 and SAMD9L have potential effects on the survival rate of patients,and there was a positive correlation between them(r=0.86,P<0.001).The levels of serum IFN-β,CXCL10,IFI44L and TNF-αin GBM patients were higher than the control group(all P<0.001).The expression of SAMD9L in GBM tissues was significantly higher than that of normal tissues around the tumor(6.00±2.98 vs.1.06±0.49,P<0.001),and the expression of IFIH1 was also significantly higher than that of normal tissues around the tumor(4.05±1.90 vs.1.01±0.57,P<0.001),and the expression of IFIH1 and SAMD9L in GBM tissues are positively correlated(r=0.663,P<0.001).IFIH1 and SAMD9L gene expressions were positively correlated with serum IFN-βand CXCL10 levels(all P<0.05).The median overall survival(OS)of high expression group of IFIH1 and SAMD9L were 16.5 months and 17 months respectively,which were lower than those of low expression group(P<0.05).Conclusion The expressions of IFIH1 and SAMD9L genes in GBM patients were up-regulated,and there was a correlation between them.Up-regulation of their expressions can reduce the survival rate of GBM patients.They are closely related to the activation of the body s anti-tumor immune system,and may be new targets for immunotherapy of GBM.