Transient receptor potential vanilloid type 4 channels mediate bladder cancer cell proliferation, migration, and chemoresistance.

Bladder cancer (BLCA) is the second most common urologic cancer in the United States and worldwide and mostly affects the aging population. Despite several ongoing clinical trials, treatment paradigms for BLCA have not changed significantly. Here, we investigated the expression of transient receptor potential vanilloid type 4 (TRPV4) in patients with BLCA and its role in calcium influx, cell proliferation, and migration using normal human urothelial cells and BLCA cells. Bioinformatic analysis of the University of Alabama at Birmingham Cancer Data Analysis Portal and cBioPortal databases revealed that TRPV4 expression is significantly higher in human BLCA tissues than in normal adjacent tissues. Furthermore, TRPV4 expression was markedly elevated in early-stage BLCA and upregulated in muscle-invasive bladder cancer tissues. TRPV4 is expressed in both normal urothelial (SV-HUC-1) and BLCA (T-24) cells, and functional assays demonstrated enhanced TRPV4-mediated calcium influx in T-24 compared with SV-HUC-1 cells. T-24 cells exhibited higher spreading on extracellular matrix gels with increasing stiffness (0.2, 8, and 50 kPa) and exhibited a migratory phenotype compared to SV-HUC-1 cells. Pharmacological inhibition of TRPV4 significantly reduced proliferation and migration in T-24 cells but had minimal effects on normal cells. Finally, treatment with cisplatin significantly reduced TRPV4 protein levels and TRPV4-mediated calcium influx in chemosensitive UM-UC-3 cells but remained unchanged in chemoresistant T-24 cells, suggesting a potential role of TRPV4 in chemoresistance. In conclusion, TRPV4 may contribute to BLCA progression by regulating cell proliferation and migration and may impart resistance to chemotherapy. Targeting TRPV4 could present a novel therapeutic approach for managing BLCA progression and overcoming chemoresistance. SIGNIFICANCE STATEMENT: This study identified transient receptor potential vanilloid type 4 (TRPV4) as a critical driver of bladder cancer (BLCA) progression. TRPV4 gene expression is elevated in both early-stage and muscle-invasive BLCA tissues. Importantly, TRPV4 inhibition selectively reduces BLCA growth and motility. Furthermore, TRPV4 is downregulated by cisplatin in chemosensitive but not chemoresistant BLCA cells, underscoring its key role in bladder cancer chemoresistance. These findings position TRPV4 as a therapeutic target for enhancing BLCA treatment and overcoming drug resistance.