The Significance Of NR3C2 Expression And Its Effect On Prognosis In Colorectal Cancer: A Study Based On TCGA Database

Objective:Colorectal cancer（CRC）is one of the common gastrointestinal malignancies with high morbidity and mortality worldwide.Although the level of CRC diagnosis gets great development,but the early diagnostic rate and prognosis is still poor.Domestic and foreign researches show that NR3C2 is associated with multiple tumors and therefore this research mainly explores the significance of NR3C2 expression and the effect of its expression on prognosis in CRC and it can provide new ideas for potential pathogenesis,treatment strategies and related therapeutic targets,as well as to guide molecular mechanism research on CRC.Methods:NR3C2 expression files and corresponding clinical data of CRC were downloaded from TCGA database.R software was used to analyze the difference of NR3C2 expression in colorectal tumor tissues and normal tissues,and the Wilcoxon and Kruskal-Wallis signed rank test was applied to analyze correlation between NR3C2 expression with clinical characteristics of CRC patients.Kaplan-Meier method was used to analyze relationship between NR3C2 expression with prognosis of CRC patients.The influence of NR3C2 expression on overall survival time of CRC patients was researched by COX univariate and multivariate analysis.GSEA enrichment analyzed the signal pathways that NR3C2 may participate.The correlation between NR3C2 and tumor microenvironment（TME）was evaluated by the ESTIMATE algorithm and spearman correlation coefficient,and further cibersort algorithm was used to analyze the relationship between NR3C2 expression and infiltration immune cells of CRC tissues.The co-expression genes and immune checkpoint genes of NR3C2 was predicted according to pearson correlation coefficient,and a molecular interaction network map of regulating NR3C2 was constructed by GCBI database.Results:Downloaded from TCGA database and screened according to inclusion criteria,the gene expression data with 37 colorectal normal tissue samples and 374 tumor tissue samples（including corresponding clinical data of CRC patients）were retained and further analyzed.The NR3C2 average expression was higher in 37 normal colorectal tissue samples than in 374 tumor tissue samples(P=2.8×10^-23),of which 27matching samples from the same patient was also higher in normal tissues(P=4.2×10^-10).The NR3C2 expression level was negatively correlated with distant metastasis（P=0.007）,lymph node metastasis（P=0.001）and TNM staging（P=0.006）and NR3C2 expression level in colorectal adenocarcinoma was higher than in rectal adenocarcinoma.Kaplan-Meier survival analysis found that 5 year survival rate of CRC patients was higher in the high NR3C2 expression group than in the low NR3C2 expression group among 374 colorectal cancer patients group(P=2.807×10^-4),266colon cancer patients subgroup（P=0.005）and 108 rectal cancer patients subgroup（P=0.011）.Univariate COX analysis showed that age（P=0.006,HR=2.100,95%CI=1.237-3.546）,TNM staging（P<0.001,HR=3.241,95%CI=2.357-4.457）,depth of tumor infiltration（P<0.001,HR=3.410,95%CI=2.060-5.646）,distantmetastasis（P<0.001,HR=7.477,95%CI=4.490-12.450）,lymph node metastasis（P<0.001,HR=2.368,95%CI=1.757-3.192）and NR3C2 expression level（P<0.001,HR=0.709,95%CI=0.590-0.851）were significantly correlated with the overall survival of CRC patients,and there was no statistical significance for gender and pathological type.Multivariate analysis showed that age（P<0.001,HR=3.455,95%CI=1.594-6.107）and NR3C2 expression level（P=0.005,HR=0.765,95%CI=0.636-0.921）were significantly correlated with overall survival of CRC patients,and were independent prognostic factors for CRC patients.GSEA analysis suggested that the high NR3C2 expression group may activate six signaling pathways including cell apoptosis,o-glycan biosynthesis,GnRH signaling pathway,T cell receptor signaling pathway,B cell receptor signaling pathway and natural killer cell mediated cytotoxicity signaling pathway and may inhibit two signaling pathways including ribosome and RNA polymerase.The correlation analysis between NR3C2 and TME showed that the expression of NR3C2 was positively correlated with the immune score of TME,with a correlation coefficient of 0.12,but not with the stromal score.The correlation between NR3C2 expression and infiltration immune cell in colon cancer tissues found that the proportion of naive B cells,CD8+T cells,CD4+memory T cells,macrophage M1 and mast cells in the high NR3C2 expression sample group was higher than that in the low expression sample group,but the proportion of macrophage M0 was lower.Gene co-expression analysis suggested that NR3C2 expression was significantly positively correlated with 648 genes（including SLC4A4,KLF4,AHCYL2,UGP2 and BCAS1,etc.）and negatively correlated with 16 genes（including RTKN,SMYD5,METTL1,MRGBP and MTHFD1L,etc.）（R>0.5,P<0.05）,among which 21 were positively correlated and 3 were negatively correlated to co-express immune checkpoint genes.According to the GCBI database showed that human 6 miRNAs（including miR-944,miR-148b-3p,miR-335-5p,miR-124-3p,miR-135a-5p,miR-19b-3p）,53 lncRNAs（including TEX41,TARID,PTCSC2,etc.）,27 interacting proteins,including（UBC,TCS22D3,STUB1,etc.）and 15 genes（including SGK1,SCNN1G and SCNN1B,etc.）may be involved in the regulation of NR3C2.Conclusion:In colorectal tumors,the expression of NR3C2 in normal tissues is higher,which is related to distant metastasis,lymph node metastasis,TNM stage and pathological classification of patients.In addition,the five years survival rate of patients in the NR3C2 high expression group is higher,which is an independent prognostic factor for colorectal cancer patients and may become an important prognostic biomarker.NR3C2 acts as an tumor suppressor gene in colorectal tumor and may inhibit colorectal tumor growth through cell apoptosis,o-glycan biosynthesis,fatty acid metabolism,GnRH signaling pathway,T cell receptor signaling pathway,B cell receptor signaling pathway,natural killer cell mediated cytotoxicity signaling pathway,ribosome and RNA polymerase signaling pathway.NR3C2 may be involved in the immune process,and regulate colorectal tumor immune microenvironment（TIME）,and positively correlate with the immune score,and may recruit of B cells naive B cells,CD8+T cells,CD4+memory T cells,macrophages M1,mast cells and macrophages M0 to increase the anti-tumor immunity.NR3C2expression was significantly positively correlated with 648 genes,and negatively correlated with 16 genes,which may play cancer suppressor gene effect in tumors.Among them,21 positive correlations and 3 negative correlations co-expressed the immune checkpoint gene,which can guide the immunotherapy of patients with high and low NR3C2 expression in colorectal cancer.Various miRNAs,lncRNAs,genes and proteins may be interactive with the regulation of NR3C2,which can provide ideas for further research.