Tamoxifen tolerance and steroid receptors in a tumor model.
In a rat mammary adenocarcinoma model, prolonged exposure to the antiestrogen Tamoxifen results in a Tamoxifen-tolerant tumor cell line which is readily transplantable and grows under continuous oral intake of the drug. The solid tumor contains steroid receptors; however, the level of Tamoxifen needed for effective displacement of diethylstilbestrol cannot be achieved with therapeutical doses; resistance to Tamoxifen is not the result of diminished or absent estrogen receptors.
Kellen
J A
JA
Sunnybrook Medical Centre, University of Toronto, Ontario, Canada.
Sutherland
D J
DJ
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*; D013629:Tamoxifen / Q000494:pharmacology*
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen