Droloxifene is a non-steroidal selective estrogen receptor modulator (SERM) and derivative of tamoxifen .1 Droloxifene binds to the estrogen receptor (ER) in rabbit uterine homogenates (IC50 = 24 nM in a radioligand binding assay) and inhibits expression of an estrogen-dependent luciferase reporter induced by 17β-estradiol .2,3 It inhibits 17β-estradiol-stimulated growth of MCF-7, ZR-75-1, and T47D human breast cancer cells in a concentration-dependent manner.4 Droloxifene (10 mg/kg) increases wet uterine weight in mice.5
1.Robertson, J.F.R.Selective oestrogen receptor modulators/new antioestrogens: A clinical perspectiveCancer Treat. Rev.30(8)695-706(2004) 2.L?ser, R., Seibel, K., Roos, W., et al.In vivo and in vitro antiestrogenic action of 3-hydroxytamoxifen, tamoxifen and 4-hydroxytamoxifenEur. J. Cancer Clin. Oncol.21(8)985-990(1985) 3.Shen, E.S., Meade, E.H., Pérez, M.C., et al.Expression of functional estrogen receptors and galanin messenger ribonucleic acid in immortalized luteinizing hormone-releasing hormone neurons: Estrogenic control of galanin gene expressionEndocrinology139(3)939-948(1998) 4.Kawamura, I., Mizota, T., Lacey, E., et al.The estrogenic and antiestrogenic activities of droloxifene in human breast cancersJpn. J. Pharmacol.63(1)27-34(1993) 5.Greenberger, L.M., Annable, T., Collins, K.I., et al.A new antiestrogen, 2-(4-hydroxy-phenyl)-3-methyl-1-[4-(2-piperidin-1-yl-ethoxy)-benzyl]-1H-indol-5-ol hydrochloride (ERA-923), inhibits the growth of tamoxifen-sensitive and -resistant tumors and is devoid of uterotropic effects in mice and ratsClin. Cancer Res.7(10)3166-3177(2001)