The effect of serotonin and serotonin antagonists on bladder cancer cell proliferation

OBJECTIVE To investigate the role of serotonin (5‐hydroxytryptamine, 5HT) and its antagonists in the proliferation of high‐grade bladder cancer cells (HT1376), as high‐grade bladder cancer has a rapid rate of progression, invasion and recurrence, and 5HT antagonists inhibit the growth of the prostate cancer cell line (PC3). MATERIALS AND METHODS HT1376 (human grade III transitional cell carcinoma) cells were incubated with either 5HT or 5HT antagonists (5HT1A, 5HT1B, 5HT1D, 5HT2, 5HT3 and 5HT4). After 72 h, cell viability was assessed using the crystal violet assay. The presence of 5HT receptor subtypes on HT1376 cells and sections of human bladder cancer tissue was determined by immunohistochemistry and Western blot analysis. RESULTS 5HT caused a dose‐dependent increase in the proliferation of HT1376 cells. The maximum increase in cell proliferation (12%; 12 samples, P