title: Regulation of progesterone receptor mRNA by oestradiol and antioestrogens in breast cancer cell lines.
abstract: The induction of progesterone receptor mRNA by oestradiol and antioestrogens has been characterised in the MCF-7 breast cancer cell line. Progesterone receptor mRNA was induced more than 100-fold by oestradiol. The induction was half-maximal in the presence of 10(-10) M oestradiol and maximum levels were reached after 24 h treatment. Progesterone receptor mRNA was induced to 10% of the oestrogen-induced level by tamoxifen and its metabolite 4'-hydroxytamoxifen. The increase was half-maximal in the presence of 5 X 10(-8) M tamoxifen or 5 X 10(-10) M 4'-hydroxytamoxifen. In contrast, neither the benzothiophene antioestrogen LY117018 nor the 7 alpha-alkyl steroidal antioestrogen ICI 164,384 had any effect on progesterone receptor mRNA. The progesterone receptor mRNA was also induced by oestrogen in a T47D subline and in two other oestrogen-responsive breast cancer cell lines (ZR-75, EFM-19). Tamoxifen was a partial oestrogen for progesterone receptor mRNA induction in each of these cell lines. The large induction of the progesterone receptor mRNA by oestrogen in all 4 breast cancer cell lines supports the contention that the progesterone receptor may be a good predictive marker of hormonal response in human breast cancer.
authors.affiliation: University Department of Pathology, Royal Victoria Infirmary, Newcastle upon Tyne, U.K.
authors.forename: F E
authors.initials: FE
authors.lastname: May
authors.forename: M D
authors.initials: MD
authors.lastname: Johnson
authors.forename: L R
authors.initials: LR
authors.lastname: Wiseman
authors.forename: A E
authors.initials: AE
authors.lastname: Wakeling
authors.forename: P
authors.initials: P
authors.lastname: Kastner
authors.forename: B R
authors.initials: BR
authors.lastname: Westley
mesh_terms: D000818:Animals; D001345:Autoradiography; D015152:Blotting, Northern; D004591:Electrophoresis, Polyacrylamide Gel; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D008325:Mammary Neoplasms, Experimental / Q000503:physiopathology; D053284:Polyunsaturated Alkamides; D011759:Pyrrolidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000502:physiology*; D011980:Receptors, Progesterone / Q000187:drug effects / Q000502:physiology*; D013629:Tamoxifen / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D004965:Estrogen Antagonists; D053284:Polyunsaturated Alkamides; D011759:Pyrrolidines; D012333:RNA, Messenger; D011980:Receptors, Progesterone; D013876:Thiophenes; D013629:Tamoxifen; D004958:Estradiol; C025430:LY 117018; C051781:ICI 164384