Antiestrogen action in mammary cancer and in fetal cells.
The present data confirm the very complicity of the response of antiestrogen when this compound is studied in different experimental conditions. The new and potent antiestrogen ICI 164,384, which is considered as a full antagonist in most models studied, concerning the progesterone receptor in the isolated cells of the uterus and vagina of guinea-pig acts as a real agonist. However, this compound antagonizes cell proliferation, progesterone receptor, and decreases the concentration of estradiol in different hormone-dependent mammary cancer cell lines. Another interesting aspect is the response of the antiestrogen 4-hydroxytamoxifen which in isolated cells of very close tissues such as the uterus and vagina is an antagonist for the former and agonist for the latter concerning the progesterone receptor. In conclusion, the present data added new information in the complicity of the mechanism of action of antiestrogens, but using new models interesting possibilities are opened to understand their responses and their mechanism.
Pasqualini
J R
JR
C.N.R.S. Steroid Hormone Research Unit, Foundation for Hormone Research, Paris, France.
Giambiagi
N
N
Gelly
C
C
Chetrite
G
G
D000818:Animals; D002478:Cells, Cultured; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology*; D005260:Female; D005333:Fetus / Q000166:cytology / Q000187:drug effects; D006168:Guinea Pigs; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D053284:Polyunsaturated Alkamides; D014407:Tumor Cells, Cultured; D014599:Uterus / Q000196:embryology; D014621:Vagina / Q000196:embryology
D004965:Estrogen Antagonists; D053284:Polyunsaturated Alkamides; D004958:Estradiol; C051781:ICI 164384