Anti-mitogenic and apoptotic effects of 5-HT1B receptor antagonist on HT29 colorectal cancer cell line.

PURPOSE: There is lack of evidence about impact of 5-HT receptors on colorectal cancers. The current study was designed to investigate the role of serotonin and its receptors in colorectal cancer cell line and tissues. METHODS: In cell cultures, we investigated the effects of 5-HT and 5-HT(1A,1B,1D) agonists and antagonists on proliferation of HT29 cells. We also tested apoptosis for the receptor antagonists. The expression of 5-HT1(A,B,D) receptor subtypes was examined by immunohistochemistry and western blotting. RESULTS: Our data indicated that 5-HT(1B) receptor was fully expressed in HT29 cell line and tumor tissues. MTT proliferation assay also revealed that serotonin and CP93129 dihydrochloride, a selective 5-HT(1B) receptor agonist, stimulated growth of HT29 cells. Further, SB224289 hydrochloride (that is a selective 5-HT(1B) receptor antagonist) had anti-proliferative and apoptotic effects on HT29 cells. CONCLUSIONS: The findings of this study provide evidence for the potential role of 5-HT(1B) receptor in colorectal cancer. Further investigation is required to explore the effect of receptor antagonists on the prevention, prognosis and treatment of patients with colorectal cancer.