Activation of TRPV3 channels in bladder cancer cells stimulates ATP release.

Transient receptor potential vanilloid 3 (TRPV3) is a thermosensitive Ca(2+)-permeable ion channel that plays essential roles in epithelial barrier function. Although its expression and function have been well characterized in the skin and, to a lesser extent, in the gastrointestinal tract, its role in the urinary bladder has remained unexplored. In this study, TRPV3 was identified in human bladder cancer cell lines, and its functional activation was demonstrated, using a novel small-molecule agonist activator of TRPV3 channel 1 (AV3-1), discovered through medium-throughput screening. AV3-1 activated mouse and human TRPV3 channels with higher potency than known TRPV3 activators in Ca(2+) assays and electrophysiological recordings. TRPV3 activation in the KU-19-19 bladder cancer cells stimulated ATP release, which was abolished by pharmacological TRPV3 blockade, confirming target specificity. Cholesterol supplementation further enhanced TRPV3 activity in KU-19-19 cells, a finding of potential relevance given the known dysregulation of cholesterol metabolism in bladder cancer. These results provide the first evidence of functional TRPV3 expression in bladder cancer cells and suggest that TRPV3 may contribute to Ca(2+)- and cholesterol-dependent signaling pathways. Collectively, these findings support further investigation of TRPV3 as a potential pharmacological target and exploratory biomarker in urothelial carcinoma. SIGNIFICANCE STATEMENT: TRPV3 is an ion channel mainly found in the skin. This study has identified the small molecule AV3-1 as a novel TRPV3 activator. Using AV3-1, this study demonstrates TRPV3 expression in bladder cancer cells. TRPV3 activation in these cells triggers ATP release, a signal potentially promoting cancer progression.