Renal clear cancer cells regulate the differentiation of urine-derived stem cells to carcinoma-associated fibroblasts via RUNX3/TGF-β1 signaling axis.

Clear cell renal cell carcinoma (ccRCC), the most common pathological subtype of renal cancer, is one of the significant health concerns due to limited clinically effective treatments. Nevertheless, targeting carcinoma-associated fibroblasts in the tumor microenvironment has emerged as a promising innovative strategy for renal cancer therapy. Thus, this study is aimed to explore the role and molecular mechanism of urine-derived stem cells (USCs) in the progression and metastasis of ccRCC. Initially, wound-healing and transwell experiments were used to assess the migration and invasion abilities of the cells. Then, western blot analysis (WB) and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analyses were used to demonstrate the relevant protein and messenger RNA expression levels. Finally, hematoxylin-eosin and immunohistochemical stainings were performed to evaluate metastasis and protein expression in lung tumors. The coculture of USCs with the ccRCC cell lines significantly enhanced their migratory and invasive abilities. WB and qRT-PCR analyses exhibited that ccRCC cell lines significantly increased cell mobility markers transcriptional and protein levels in USCs. Finally, the in vivo investigations in nude mice showed that USCs promoted the proliferation and migration of ccRCC-based xenograft tumors. In summary, these findings demonstrated that USCs promoted ccRCC tumorigenesis and development in vivo and in vitro by regulating the Runt-related transcription factor 3/transforming growth factor-β1 signaling axis.