Pan-cancer analysis of CXCR4 carcinogenesis in human tumors

BACKGROUND: C-X-C chemokine receptor 4 (CXCR4) is a specific receptor of stromal cell-derived factor-1, also known as CXCL12. The interaction between CXCL12 and its receptor CXCR4 can activate various signaling pathways, including gene expression, cell proliferation, migration, tumorigenesis, angiogenesis, etc. Although there is evidence to support the association between CXCR4 and some cancers, there is no pan-cancer analysis. To fill this gap, we analyzed the role of CXCR4 in cancer-based on The Cancer Genome Atlas (TCGA). METHODS: We used TCGA, Genotype-Tissue Expression (GTEx) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases to analyze the expression, variation and phosphorylation of CXCR4 in different cancers. At the same time, we also carried out Kyoto Encyclopedia of Genes (KEGG) and Gene Ontology (GO) enrichment analysis. RESULTS: We found that CXCR4 expression was significantly increased in bladder urothelial carcinoma (BLCA) and other cancers, and CXCR4 expression in BLCA, cervical squamous cell carcinoma (CESC) and other cancers was related to tumor stage. CXCR4 expression was positively correlated with tumor-associated fibroblasts in BLCA, breast adenocarcinoma (BRCA), CESC and other cancers. GO analysis showed that CXCR4-related genes were mainly enriched in biological processes (BPs) and cellular components (CCs). KEGG analysis showed that CXCR4 was mainly involved in “chemokine signaling pathway”, “natural killer cell-mediated cytotoxicity”, and “JAK-STAT signaling pathway”. CONCLUSIONS: The expression of CXCR4 in different cancers has different effects on the prognosis of patients and the infiltration of immune cells.