title: Difference in extractability of estradiol- and tamoxifen-receptor complex in the nuclei from MCF-7 cells with Nonidet P-40.
abstract: The extraction of [3H]estradiol- and [3H]tamoxifen-receptor complex in the nuclei from MCF-7 cells with the nonionic detergent Nonidet P-40 has been studied. We found that there is a striking difference in the extractability of estradiol- and tamoxifen-receptor complex from nuclei with 0.5% Nonidet P-40. The nuclear bound estradiol-receptor complex is scarcely extractable with Nonidet P-40. In contrast, almost all of the nuclear bound tamoxifen-receptor complex is extractable. The nuclear [3H]tamoxifen-receptor complex extracted in the presence of Nonidet P-40 sediments in two peaks at 7 S and 5 S. The latter sedimentation rate is the same with that of the nuclear [3H]tamoxifen-receptor complex extracted with 0.4 M KCl. The nuclear [3H]estradiol-receptor complex extracted with 0.4 M KCl sediments at 4 S. The results suggest that interaction of tamoxifen-receptor complex with chromatin is different from that of estradiol-receptor complex.
mesh_terms: D001943:Breast Neoplasms / Q000032:analysis; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis; D005260:Female; D006801:Humans; D017830:Octoxynol; D011092:Polyethylene Glycols; D011955:Receptors, Drug; D011959:Receptors, Estradiol / Q000302:isolation & purification*; D011960:Receptors, Estrogen / Q000302:isolation & purification*; D013629:Tamoxifen / Q000302:isolation & purification*
chemical_list: D011955:Receptors, Drug; D011959:Receptors, Estradiol; D011960:Receptors, Estrogen; D013629:Tamoxifen; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40