Prognosis And Mechanism Prediction Of The SARS-CoV-2 Receptor ACE2 And TMPRSS2 In Renal Cancer Patients

Background and objective: Since December 2019,the respiratory disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has exploded globally.At present,coronavirus disease 2019(COVID-19)caused by the virus still posed a serious threats and challenges to public health and life.As of late March 2022,the number of confirmed COVID-19 cases in the world has exceeded 470 million,and 6.1 million deaths.Among them,COVID-19 patients are often more seriously ill with multiple underlying diseases,such as cancer,cardiovascular disease,diabetes and chronic kidney disease.It is urgent to find factors that affect the prognosis of COVID-19 patients with underlying diseases.Angiotensin converting enzyme 2(ACE2)and transmembrane protease serine 2(TMPRSS2)were major receptor for SARS-CoV-2,which had been proven to be highly expressed in kidney,intestine,lung and other tissues.In addition to the lungs,the kidneys have been shown to be one of the target organs for SARS-CoV-2 infection,suggesting that ACE2 and TMPRSS2 may be key prognostic factors in renal cancer patients.However,their functions in renal cancer are unclear.Therefore,it is necessary to explore the expression levels and prognostic value of ACE2 and TMPRSS2 in renal cancer,and the m RNA expression changes of ACE2 and TMPRSS2 after SARS-CoV infection to provide reference for clinical diagnosis and treatment in renal cancer with SARS-CoV-2infected.Methods:(1)ACE2 and TMPRSS2 expression in human tissues was download from University California of Santa Cruz(UCSC Xena)for 31 human normal tissues;The gene expression data and clinical information of renal cancer patients were extracted from the Cancer Genome Atlas(TCGA)database.Differential expression analysis was performed by R version 3.6.3 to identify the differentially expression of ACE2 and TMPRSS2 in KIRC and KIRP.(2)Using the Human Protein Atlas(HPA)and Image pro software to calculate the protein levels of ACE2 and TMPRSS2 in renal cancer;To explore the m RNA expression regulation mechanism of ACE2 and TMPRSS2,we used UALCAN cancer database and Gene Set Cancer Analysis(GSCA)to analyze DNA methylation levels and copy number changes of ACE2 and TMPRSS2.(3)Univariate and multivariate Cox regression analysis was performed to analyze the risk factors of overall survival in patients with renal cancer.and the survival curves and receiver operating characteristic(ROC)curves were plotted to evaluate their prognostic ability.The nomogram package was used to established a best predictive model for the prognosis of renal cancer patients.(4)Potential mechanism of ACE2 was explored by the gene sets enrichment analysis(GSEA),a method to determine whether members of a previously defined gene set are correlated with the phenotypic class distinction;Weighted gene co-expression network analysis(WGCNA)was used to assess the co-expression of genes with ACE2 in KIRC and KIRP,and the network of them were visualized using Cytoscape v3.7.2.(5)The correlation between ACE2 levels and immune cell markers was evaluated using Pearson’s correlation;A total of 265 small molecules or drugs were obtained from the Genomics of Drug Sensitivity in Cancer(GDSC)database.Spearman’s coefficient was used to analyze the correlation between gene expression and drug sensitivity.(6)The gene expression data of ACE2 and TMPRSS2 in coronavirus(SARS-CoV)infection samples were obtained from the Gene Expression Omnibus(GEO)to analyze the expression changes of ACE2 and TMPRSS2 after SARS-CoV infection.Results:(1)ACE2 and TMPRSS2 were widely distributed in human normal tissues,such as in the small intestine,heart,stomach,pancreas and testis,especially their expression levels were both high in the kidney.(2)The m RNA and protein expression levels of ACE2 were both significantly up-regulated in KIRC and KIRP,while the m RNA and protein expression levels of TMPRSS2 were significantly down-regulated in KIRC and KIRP;Moreover,their m RNA expression were regulated by DNA methylation.(3)KIRC or KIRP patients with lower ACE2 expression showed poor overall survival,and the expression levels of ACE2 were lower in advanced TNM stages.In contrast,TMPRSS2 expression was not significantly associated with overall survival.Based on the clinical risk factors of the overall survival,we integrated ACE2 and overall survivalrelated factors to construct a nomogram,which showed a good predictive ability.(4)GSEA analysis results showed that enriched gene sets were closely correlated with metabolic pathways in both KIRC and KIRP,most of which were upregulated in ACE2high-expression group,inducing glycolysis and gluconeogenesis,peroxisomes,fatty acid metabolism and lipogenesis etc.;WGCNA screened 7 co-expressed genes that had strong correlation with ACE2 in KIRC and KIRP.These genes were also related to the modulation of metabolism and membrane transport in the body,and their expression levels were associated with the survival of renal cancer patients.(5)The correlation analysis of ACE2 and immune infiltration showed that ACE2 had a negative correlation with immune cell markers in KIRC and KIRP,including CD79 A and CD9 in B cells,PTGS2 in M1 macrophages,BCL6 in follicular helper T cells,and STAT5 B and TGFB in regulatory T cells;Drug sensitivity and gene expression profiling data of cancer cell lines in the GDSC database were integrated and found that low ACE2 expression was associated with the drug resistance of epidermal growth factor receptor tyrosine kinase inhibitors(Gefitinib,Afatinib).(6)In the SARS-CoV infection model,the expression of ACE2 was significantly down-regulated in the infected group,while the expression of TMPRSS2 had no significant change.Conclusion: Lower ACE2 expression was significantly associated with the poor prognosis of renal cancer patients,and it can promote the disease progression of renal cancer patients by affecting metabolism,immune pathways and drug sensitivity.ACE2 plays a more crucial role in the diagnosis and prognosis of renal cancer patients.Coronavirus can lead to the downregulation of ACE2,suggesting that renal cancer patients with COVID-19 may have more severe disease development and poor prognosis than ordinary infected patients.Attention should be paid to the evaluation and monitoring of ACE2 expression,metabolic and immune-related indicators.