title: [Cancer of the breast, mechanism of action of anti-estrogens].
abstract: Estrone sulfate (E1-S) is quantitatively the main estrogen in human breast cancer tissue. This sulfate is converted with a great yield into estradiol (E2) in different hormone-dependent mammary cancer cell lines (MCF-7, R-27, T-47D). In opposition, there is small or no conversion in the hormone-independent cell lines (MDA-231 and MDA-436). The anti-estrogen tamoxifen blocks the conversion of E1-S to E2 in the MCF-7 and R-27 lines but not in the T-47D cell line. A new anti-estrogen: ICI 164,384 is also very active to block this conversion. In conclusion, the most probable way of action of the antiestrogen in through the competitive binding to the estrogen receptor; however recent date suggests other possible pathways.
authors.affiliation: Equipe de Recherche du CNRS, n. UA-548, Fondation de Recherche en Hormonologie, Paris, France.
authors.forename: J R
authors.initials: JR
authors.lastname: Pasqualini
authors.forename: C
authors.initials: C
authors.lastname: Gelly
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002461:Cell Line, Transformed; D004958:Estradiol / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D004970:Estrone / Q000378:metabolism; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism*; D053284:Polyunsaturated Alkamides; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D053284:Polyunsaturated Alkamides; D013629:Tamoxifen; D004970:Estrone; D004958:Estradiol; C051781:ICI 164384
vernacular_title: Cancer du sein, mécanisme d'action des anti-oestrogènes.