title: [Hormone-dependency of human breast cancer in in vitro clonogenic assay].
abstract: The in vitro clonogenic assay has been used to assess the biological effects of estradiol-17 beta (E 2) and an antiestrogen, tamoxifen (TAM) on human breast cancer, and the results were compared with the estrogen receptor status (ER). The sera used were treated with dextran-coated charcoal to avoid the modification effects of the endogenous hormones. There was a significant difference between ER (+) and ER (-) breast cancers in the incidence of cases in which the plating efficiency of cancers increased more than 50% over those of untreated control by adding 10(-8) M of E 2 (40.2% vs. 21.3%). TAM, 10(-6) M revealed a less than 50% colony formation of the control in 30.5% of ER (+) cancers, whereas only 13.0% of ER (-) cancers showed a response to TAM.
mesh_terms: D001943:Breast Neoplasms / Q000032:analysis*; D005260:Female; D006801:Humans; D009376:Neoplasms, Hormone-Dependent / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis*; D013629:Tamoxifen / Q000494:pharmacology; D014410:Tumor Stem Cell Assay
chemical_list: D011960:Receptors, Estrogen; D013629:Tamoxifen