Competitive binding assay for estrogen receptor in monolayer culture: measure of receptor activation potency.
MCF-7 cells were incubated with [3H]estradiol, unlabeled estradiol and various estrogens or antiestrogens to measure their relative binding affinity (whole-cell assay). Comparison of the values with those previously established on uterine cytosol with a DCC assay revealed a good parallelism for both steroid and diphenolic diethylstilbestrol based estrogens. On the contrary, in the whole-cell assay, antiestrogens and weak estrogens of the triphenyl- and gem-diphenylethylene categories always displayed low values which were in the order of magnitude found with weak steroid estrogens. This property was not due to a reduction of binding capacity, nor to the presence in some compounds of an ethoxyaminoalkyl side-chain (source of antiestrogenicity). In view of all these data, it was concluded that the present test would provide an estimate of the ability of a given compound to transform the receptor in a form which interacts with genomic sites involved in the regulation of "estrogenic-induced products" ("activation").
D001667:Binding, Competitive; D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D002606:Charcoal; D055598:Chemical Phenomena; D002621:Chemistry; D003600:Cytosol / Q000378:metabolism; D003911:Dextrans; D004958:Estradiol / Q000378:metabolism; D004965:Estrogen Antagonists / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism; D005260:Female; D006801:Humans; D011960:Receptors, Estrogen / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014599:Uterus / Q000378:metabolism
D003911:Dextrans; D004965:Estrogen Antagonists; D004967:Estrogens; D011960:Receptors, Estrogen; D002606:Charcoal; D004958:Estradiol