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

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. 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. 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. 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.