Analysis Of IL-33 Expression In Colorectal Cancer And Its Clinical Significance Based On Public Database

Objectives:This study aims to analyze the expression of interleukin-33 in colorectal cancer and its clinical significance by mining the gene expression,patient clinical information and other relevant data in public databases and immunohistochemical staining of CRC.Methods:1、analyze the difference of IL-33 expression in CRC and normal colorectal tissues by using Oncomine database;2、analyze the difference of IL-33 expression in tissues of different CRC subgroups patients;3、Use the clinical information and IL-33 RNA expression data of CRC patients in the TCGA database to analyze the correlation between high and low IL-33 expression and clinicopathological characteristics of patients;4、Use the Survival information and IL-33 RNA expression data of CRC patients in TCGA database for survival analysis and Kaplan-Meier prognostic model;5、Construct a prognostic nomogram model for predicting the prognosis of patients with colorectal cancer by using TCGA database and verify its accuracy;6、Analyse the correlation between the expression of IL-33and the level of infiltration of 6 immune cells in CRC by using the TIMER database;7、Analyse the Correlation of IL-33 and immune checkpoint molecules of CRC by using the TCGA database;8、Analyse the IL-33 co-expressed genes in CRC by using Linked Omics database;9、Analyse the IL-33 protein expression levels in CRC and paracancerous tissues by immunohistochemical experiments.Results:1、Oncomine database analysis revealed that IL-33 was significantly overexpressed in CRC tissues(P<0.05).2、Ualcan database analysis revealed IL-33 was significantly overexpressed in CRC tissues in different subgroups of patients(P<0.05).3、TCGA database revealed that the IL-33 expression and age(X~2=0.849,P=0.357),gender(X~2=1.022,P=0.312),depth of infiltration(X~2=0.063,P=0.802),lymphatic metastasis(X~2=1.808,P=0.179),distant metastasis(X~2=0.107,P=0.744),TNM stage(X~2=2.092,P=0.148)of CRC patients were not statistically correlated.4、TCGA database revealed that IL-33 expression was significantly and positively associated with overall survival in CRC patients(p=0.0084).5、COX multi-factor model shows showed that age and TNM stage of CRC patients were independent risk factors for their prognosis,and the C index of nomogram model was0.723,The predicted values in the calibration curve are highly consistent with the actual observed values,which could accurately predict the one-year survival rate of CRC patients;6、TIMER database analysis revealed that IL-33 expression was significantly positively correlated with B cells(r=0.141,P<0.01)and CD8~+T cells(r=0.237,P<0.001)in colon cancer,tumor purity(r=-0.251,P<0.01)and CD4~+T cells(r=-0.232,P<0.01)were significantly negatively correlated with CD8~+T cells(r=0.242,P<0.01)in rectal cancer,and significantly positively correlated with CD8~+T cells(r=0.242,P<0.01)in rectal cancer.7、IL-33 expression was significantly correlated with the expression of immune checkpoint SIGLEC15 molecules in CRC(p<0.001),;8、Linked Omics database analysis revealed that 903 of the differentially expressed genes of IL-33 and CRC genes were significantly positively correlated and 470 genes were significantly negatively correlated(p<0.05,false discovery rate FDR<0.01),with the top three positively correlated genes being EPB41L2(r=0.42,p=7.04E-18),TMEM71(r=0.42,p=1.00E-17),PTPRD(r=0.39,p=5.11E-15),and the top three negatively correlated genes were TMEM51(r=-0.33,p=5.84E-11),RHBDF2(r=-0.31,p=3.89E-10),and COBL(r=-0.31,p=1.02E-09).GO analysis showed that the co-expressed genes of IL-33 were mainly enriched in biological processes such as mitochondrial gene expression,NADH dehydrogenase complex assembly,tricarboxylic acid metabolism,nucleoside triphosphate metabolism,etc.KEGG analysis showed that the co-expressed genes of IL-33 were mainly enriched in processes such as citric acid cycle、ribosome、PPAR signaling pathway、drug metabolism、cytokine-cytokine receptor interaction,etc.processes.9、IL-33 protein was mainly expressed in the nuclei of CRC.In 20 pairs of sections of CRC and its paracancerous tissues,the positive IL-33 staining rate was 60%and 0%,respectively,and the expression of IL-33 in CRC tissues was stronger than that in paraneoplastic tissues.Conclusions:IL-33 was significantly overexpressed in CRC.IL-33 expression was significantly and positively associated with overall survival in CRC patients,nomogram model can accurately predicts one-year survival in CRC patients.IL-33 is associated with immune infiltration of B cells,CD4~+T cells,and CD8~+T cells in CRC and may thus affect the prognosis of CRC patients.expression of IL-33 was significantly positively correlated with immune checkpoint SIGLEC15 molecule.GO and KEGG analysis showed that IL-33may be involved in mitochondrial gene expression、NADH dehydrogenase complex assembly、tricarboxylic acid metabolism、nucleoside triphosphate metabolism,citric acid cycle、ribosomes、PPAR signaling pathway、drug metabolism、PPAR signaling pathway、cytokine-cytokine receptor interaction and other processes、play a role in CRC progression and metastasis.