Renal clear cell carcinoma-derived CXCL5 drives tumor-associated fibroblast formation and facilitates cancer progression.

BACKGROUND

Kidney renal clear cell carcinoma (KIRC, ccRCC) is one of the most common and aggressive subtypes of urinary system cancer. Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) exacerbate the malignant phenotype of KIRC. It is necessary to explore further how KIRC induces normal fibroblasts (NFs) into CAFs.

METHODS

The transcriptome data of KIRC was obtained from The Cancer Genome Atlas (TCGA), and the hub-genes and their corresponding functions in the co-expression module were obtained through differential analysis, enrichment analysis, and weighted correlation network analysis (WGCNA) analysis. RT-PCR, western-blot, and Elisa assays were used to detect the expression of CXCL5 (C-X-C Motif Chemokine Ligand 5) in KIRC cells and medium. Western-blot and immunofluorescence were used to demonstrate the transformation of NFs to CAF-like cells and relevant pathways. Human umbilical vein endothelial cells (huvec) were seeded within collagen gel to represent the neo-vascular network. Transwell, scrape, colony formation, and CCK-8 assays were performed to reveal the feedback effect of KIRC cells.

RESULTS

Bioinformatics analysis showed that CXCL5 was a core gene in differential expression genes (DEGs) and was associated with extracellular matrix (ECM), which was associated with CAFs. KIRC-derived CXCL5 promoted the conversion of NFs to CAF-like cells. It included morphological and corresponding molecular marker changes. Activation of the JAK/STAT3 pathway was involved in this process. Corresponding, CAFs cells could secrete vascular endothelial growth factor (VEGF), which induced angiogenesis. CXCL5 promoted KIRC invasion and proliferation.

CONCLUSIONS

Our research suggested that KIRC-derived CXCL5 could induce NFs to become CAFs-like cells that promote angiogenesis in the TME. The positive feedback of CXCL5 promoted its own invasive growth. The intercellular communication with CXCL5 as the core might be the critical node in the occurrence and development of KIRC.