(Z)-4-Hydroxytamoxifen

4-Hydroxytamoxifen (4-OHT) is a metabolite of the antiestrogen tamoxifen in humans and other mammals. Both the Z (trans) and E (cis) 4-OHT isomers exhibit antiestrogenic properties in immature rats. Studies on the structure-function relationships of fixed ring systems have revealed that the trans isomer is a potent antiestrogen, while the cis isomer is relatively weaker (about 100 times less potent) as an antiestrogen in T47D breast cancer cells in vitro. 4-OHT binds to estrogen receptors (ER) and estrogen-related receptors (ERR), exerting both estrogenic and anti-estrogenic effects. This compound is a cell-permeable, selective estrogen receptor modulator (SERM). Compared to tamoxifen and its other metabolites, 4-OHT demonstrates a higher affinity for binding to estrogen receptors, resulting in 50 to 100-fold greater potency in inhibiting cell proliferation in normal human breast cells and breast cancer cell lines in culture. Moreover, 4-OHT has been found effective in inhibiting the growth of these cells in the absence of estrogen when cell proliferation was induced by insulin or epidermal growth factor.

(Z)-4-Hydroxytamoxifen has been used:

• as a media supplement to study the cell viability by WST-1 Assay
• for inducing deletion of transforming growth factor-β (TGF-β gene in mice
• to induce Cre recombinase activity in vitro.

This compound is featured on the Nuclear Receptors (Steroids) page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

This compound was developed by AstraZeneca. To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here.