A trisubstituted pyrazole derivative reduces DMBA-induced mammary tumor growth in rats by inhibiting estrogen receptor-α expression.

Aberrant expression of estrogen receptor alpha (ER-α) is observed in many pathological complications like breast cancer, endometrial cancer, and in osteoporosis. ER-α plays a vital role in the initiation and progression of breast cancer and confers chemo and radioresistance to the cancer cells by upregulating expression of anti-apoptotic proteins. The synthetic pyrazole derivative 3-(1-(4-bromophenyl)-5-phenyl-1H-pyrazol-3-yl)pyridine (compound 5d) displays significant cytotoxicity against mammary carcinoma cells. Molecular docking studies revealed that compound 5d binds to ligand binding domain of (ER-α). In vivo studies were carried out to investigate ER-α expression by immunohistochemistry and quantitative RT-PCR, which revealed reduction of ER-α in tumor cells upon treatment with compound 5d indicating its ER-α antagonistic effect. Our study ascertains compound 5d as a potent inhibitor of mammary carcinoma cells.