Comprehensive analysis of the role of CXCL family members in clear cell renal cell carcinoma

Abstract

Background: CXCLs are a group of low-molecular-weight growth factors secreted by cells, mainly through G protein-coupled receptors for signal transduction and induction of cell chemotactic motility. Their abnormal expression is linked to immune cell activity in cancer and tumor growth and progression. However, the differential expressions of CXCLs in ccRCC, prognostic prospects, and immune infiltration have not been clearly explored. Objective: This study aimed to analyze the expression profile of CXCL family members in clear cell renal cell carcinoma, its prognostic significance, and the correlation between CXCL family members and tumor immunity. Methods: The expression difference of CXCLs between ccRCC and normal renal tissues was analyzed by the TCGA database. The prognostic value of CXCLs in ccRCC was analyzed by the Kaplan-Meier Plotter. The copy number variation (CNV) of CXCLs in ccRCC was explored through the GSCA website. The cBioPortal online tool was used to screen out 355 co-expressed genes significantly related to CXCLs. The protein-protein interaction network of co-expressed genes was constructed using the STRING database, and the pathways that significantly enriched these genes were explored using Metascape. We then used the least absolute shrinkage and selection operator (LASSO) regression analysis to develop a predictive risk model for ccRCC patients. The relationship between CXCLs and tumor immune cell infiltration was analyzed. Finally, drugs interacting with CXCLs were analyzed using the DGIdb database. Results: It was observed that mRNA expression levels of CXCL-2,-3,-4,-5,-9,-10,-11,-13, and -16 in the tissue of KIRC were higher than normal KIRC tissue. In contrast, CXCL12 expression decreased. Furthermore, CXCL5,-9,-10,-11,-12, and -13 mRNA expression was significantly correlated with the clinical stage. In KIRC patients, elevated CXCL1,-2,-5, and -13 expression was associated with shorter overall survival, while elevated CXCL14 expression was associated with a better prognosis. Through LASSO regression analysis, we obtained a 5-gene prognostic signature. This prognostic feature is associated with the infiltration of multiple immune cells. Conclusion: In this study, we evaluated the expression levels of CXCL genes in KIRC and their prognostic potential in KIRC. CXCL-5,-9,-10,-11,-12, and -13 may be associated with ccRCC progression, and CXCL-1,-2,-5,-13, and -14 may be potential prognostic markers.