Abstract
In the search for a breast cancer prevention strategy which would avoid undesirable effects of orally administered tamoxifen, the percutaneous administration of the highly active metabolite 4OHTamoxifen (4OHTam) has been proposed. Percutaneous 4OHTam penetrates the skin to reach breast tissues. It, thus, avoids the hepatic first pass effect, and offers an optimal local/systemic effect. However, trans-4OHTamoxifen can spontaneously isomerize into the cis-isomer, which may have estrogen agonist action. The aim of this study was to examine the effect of cis-4OHTam on normal human breast epithelial (HBE) cells in culture. Spontaneous isomerization of trans- into cis-4OHTam occurred within 24–48 h, but stabilized rapidly at a trans/ cis ratio of 70/30, whether in stock solution, culture medium or cultured cells. The cis-4OHTam did not stimulate HBE cell growth according to histometric cell counts and scanning electron microscopy analysis, but inhibited E 2-induced cell growth, albeit two to three times less than trans-4OHTam. In conclusion, spontaneous isomerization of trans- to cis-4-OHTam is limited and 4OHTam retains a marked antiestrogenic effect. It may prove to be a useful alternative to tamoxifen in breast cancer prevention, especially if administered percutaneously.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Steroid Biochemistry and Molecular Biology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
