CTHRC1基因在胃癌中ceRNA调控网络构建及免疫相关性分析

Construction of ceRNA regulatory network of CTHRC1 gene in gastric cancer and analysis of immune correlation

目的构建CTHRC1基因在胃癌中的ceRNA调控网络,并进行免疫相关性分析。方法利用TCGA数据库,下载胃癌患者肿瘤组织和癌旁组织全基因组测序信息和临床信息,通过R软件分析CTHRC1基因的表达与患者预后的临床相关性,同时进行多数据库和PCR实验进行相互验证。通过starBase数据库寻找与CTHRC1基因结合的靶向miRNA、lncRNA,从而筛选出对患者总体生存率有影响的关键miRNA和lncRNA,并构建ceRNA调控网络。对CTHRC1基因的表达情况与免疫细胞的浸润量、肿瘤微环境、甲基化、肿瘤干细胞指数等多组学的相关性进行探讨。构建CTHRC1基因的PPI网络,并进行基因通路富集分析。结果胃癌患者肿瘤组织中CTHRC1基因表达量明显高于正常组织,高表达CTHRC1基因组患者总体生存时间明显短于低表达组。Cox回归分析发现CTHRC1基因表达量是影响胃癌患者总体生存时间的独立危险因素。共筛选到3个关键miRNA(hsa-let-7g-5p、hsa-let-7f-5p、hsa-miR-30b-5p)和3个关键lncRNA(MIR99AHG、CARMN、PWAR5),构建了3条ceRNA网络图。CTHRC1基因高低表达组的胃癌患者,免疫细胞浸润量明显不同,且CTHRC1基因表达与免疫检查点基因表达均呈正相关。PPI网络发现CTHRC1基因与DVL3、DVL1、DVL2、ROR2、WNT3A、FZD5、FZD6基因表达明显具有相关性,相关系数>0.9。多组学分析发现,CTHRC1基因表达与肿瘤干细胞指数、肿瘤微环境、甲基化程度均具有统计学意义上的相关性。富集分析发现CTHRC1基因在多条通路上高富集。结论MIR99AHG/CARMN-hsa-let-7g-5p-CTHRC1和PWAR5-hsa-miR-30b-5p-CTHRC1组成的3条ceRNA网络中的基因,可能是影响胃癌患者预后的关键基因,且与免疫细胞具有明显的相关性。

Objective To construct the ceRNA regulatory network of CTHRC1 gene in gastric cancer,and analyze the immune correlation.Methods The whole genome sequencing and clinical information of gastric cancer patients were downloaded from TCGA database.The clinical correlation between CTHRC1 gene expression and prognosis was analyzed by R software.Multiple databases and PCR experiments were carried out to verify each other.Through the starBase database to find the targeted miRNA and lncRNA that bind to the CTHRC1 gene,so as to screen out the key miRNA and lncRNA that affect the overall survival rate of patients,and construct the ceRNA regulatory network.To explore the correlation between the expression of CTHRC1 gene and the infiltration of immune cells,tumor microenvironment,methylation,tumor stem cell index and so on.The PPI network of CTHRC1 gene was constructed and the gene pathway enrichment analysis was carried out.Results The expression of CTHRC1 gene in tumor tissues of patients with gastric cancer was significantly higher than that in normal tissues,and the overall survival time of patients with high expression of CTHRC1 gene was significantly shorter than that of patients with low expression.Cox regression analysis showed that CTHRC1 gene expression was an independent risk factor affecting the overall survival time of patients with gastric cancer.Three key miRNA(hsa-let-7g-5p,hsa-let-7f-5p,hsa-miR-30b-5p)and three key lncRNA(MIR99AHG,CARMN,PWAR5)were screened,and three ceRNA networks were constructed.In gastric cancer patients with different expression of CTHRC1 gene,the amount of immune cell infiltration was significantly different,and the expression of CTHRC1 gene was positively correlated with immune checkpoint gene.PPI network showed that there was a significant correlation between CTHRC1 gene and DVL3,DVL1,DVL2,ROR2,WNT3A,FZD5,FZD6 gene expressions,the correlation coefficient was>0.9.Correlation analysis showed that there was a statistically significant correlation between CTHRC1 gene expression and tumor stem cell index,tumor microenvironment and the degree of methylation.Enrichment analysis showed that CTHRC1 gene was highly enriched in multiple pathways.Conclusion The three ceRNA networks composed of MIR99AHG/CARMN-hsa-let-7g-5p-CTHRC1 and PWAR5-hsa-miR-30b-5p-CTHRC1 may be the key genes affecting the prognosis of patients with gastric cancer and have a significant correlation with immune cells.