Up-regulation of estrogen receptors by nonsteroidal antiestrogens in human breast cancer.
Development of resistance to hormonal therapy in breast cancer is frequently associated with a decline or loss of cellular estrogen receptors. Agents which up-regulate the receptor may reduce the incidence of hormonal resistance. Antiestrogens at concentrations ranging from 0.1 to 1 microM produced a 2- to 4-fold increase of estrogen receptors in MCF-7 and T-47D breast cancer cells. This increase, which occurred as early as 3 h and was sustained throughout the 4 days of continuous exposure to tamoxifen, was primarily due to an enhancement in receptor synthesis.
Kiang
D T
DT
Department of Medicine, University of Minnesota Medical School, Minneapolis 55455.
Kollander
R E
RE
Thomas
T
T
Kennedy
B J
BJ
D001943:Breast Neoplasms / Q000032:analysis / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D011960:Receptors, Estrogen / Q000032:analysis / Q000096:biosynthesis*; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013997:Time Factors
D011960:Receptors, Estrogen; D013629:Tamoxifen; C016601:afimoxifene; D003513:Cycloheximide