POLR2J作为低级别胶质瘤预后标志物的可能性及其作用机制的生物信息学分析

Bioinformatics analysis of POLR2J as a prognostic marker for low-grade gliomas and its mechanism of action

目的 通过生物信息学方法分析POLR2J(RNA polymeraseⅡsubunit J,POLR2J)基因的表达水平与低级别胶质瘤(lower-grade glioma,LGG)患者预后之间的关系,并预测其作用机制。方法 利用癌症基因组图谱(The Cancer Genome Atlas,TCGA)、基因型组织表达(Genotypic Tissue Expression,GTEX)、中国胶质瘤基因组图谱(Chinese Glioma Genome Atlas,CGGA)、人类蛋白质和图谱(Human Proteins And Atlas,HPA)、临床蛋白质组学肿瘤分析协会(Clinical Proteomics Tumor Analysis Association,CPTAC)、肿瘤免疫单细胞中心(Tumor Immune Single Cell Center,TISCH2)等数据库分析POLR2J在泛癌、泛细胞、单细胞层面的基因表达和蛋白水平,使用免疫印迹分析POLR2J基因在LGG癌细胞系中的表达情况;GSE68848验证POLR2J在LGG中的表达量;使用R语言分析POLR2J与临床指标和生存预后的关系;使用TIP数据库分析POLR2J与肿瘤免疫微环境之间的关系,使用0Metascape进行功能注释分析,应用sparkle数据库分析POLR2J对LGG免疫治疗的预测效果。结果 POLR2J在LGG中高表达,POLR2J的表达量与LGG患者的不良预后正相关,受试者工作特征曲线(receiver operating characteristics curve,ROC)和COX回归分析证明POLR2J是LGG的独立预后因子;POLR2J高表达的LGG患者免疫浸润更复杂,免疫通路的激活程度也更高,也拥有更高的肿瘤突变负荷(tumor mutation burden,TMB)和基因组拷贝数变异;通路富集分析显示,POLR2J高表达的LGG患者的蛋白质代谢、氧化应激、缺氧调控、细胞迁徙等通路被显著激活。POLR2J高表达的LGG患者能够更好地响应免疫治疗。结论 LGG中高表达的POLR2J是患者预后生存的危险因素,其表达与缺氧和免疫浸润密切正相关。

Objective To analyze the relationship between the expression level of POLR2J(RNA Polymerase ⅡSubunit J,POLR2J) gene and the prognosis of low-grade glioma(LGG) patients using bioinformatics methods,and predict its mechanism of action.Methods The gene and protein expression of POLR2J at the pan cancer,pan cell,and single cell levels was analyzed using databases such as The Cancer Genome Atlas(TCGA),Genotypic Tissue Expression(GTEX),Chinese Glioma Genome Atlas(CGGA),Human Proteins and Atlas(HPA),Clinical Proteomics Tumor Analysis Association(CPTAC) and Tumor Immune Single Cell Center(TISCH2).Western blotting was used to analyze the expression of genes in LGG cancer cell lines;GSE68848 was used to verify the expression level of POLR2J in LGG;The R language is used to analyze the relationship between POLR2J and clinical indicators and survival prognosis;The TIP database was used to analyze the relationship between POLR2J and the tumor immune microenvironment;0Metascape is used for functional annotation analysis;The Sparkle database was used to analyze the predictive effect of POLR2J on LGG immunotherapy.Results POLR2J was highly expressed in LGG,and its expression level was positively correlated with poor prognosis in LGG patients.Receiver operating characteristic curve(ROC) and COX regression analysis confirmed that POLR2J is an independent prognostic factor for LGG;LGG patients with high expression of POLR2J have more complex immune infiltration,higher activation of immune pathways,and higher tumor mutation burden(TMB) and genomic copy number variability;Pathway enrichment analysis showed that protein metabolism,oxidative stress,hypoxia regulation,and cell migration pathways were significantly activated in LGG patients with high expression of POLR2J.LGG patients with high expression of the POLR2J gene were better able to respond to immunotherapy.Conclusion The high expression of POLR2J in LGG is a risk factor for patient prognosis and survival,and its expression is closely positively correlated with hypoxia and immune infiltration.