title: Estrogenic and antiproliferative properties of genistein and other flavonoids in human breast cancer cells in vitro.
abstract: Experimental and epidemiologic studies support the view that soyfoods prevent cancer as well as diseases and symptoms associated with estrogen deficiency. Recent research suggests that the isoflavonoid genistein, a phytoestrogen found in abundance in soyfoods, may be one of the principal molecular components responsible for these health benefits. In this study we investigated the effects of a broad physiologically relevant concentration range of genistein on estrogen receptor (ER) binding, induction of the estrogen-regulated antigen pS2, and cell proliferation rate in ER(+) and ER(-) human breast cancer cells grown in vitro. Dose response to genistein was compared with that of estradiol, tamoxifen, and several other structurally similar iso- and bioflavonoids (e.g., equol, kaempferol, and quercetin). Our results revealed that genistein has potent estrogen agonist and cell growth-inhibitory actions over a physiologically achievable concentration range (10 nM-20 microM). Other flavonoids over the same concentration range were good estrogen agonists and poor cell growth inhibitors (equol) or poor estrogen agonists and potent growth inhibitors (kaempferol and quercetin). The growth-inhibitory actions of flavonoids were distinctly different from those of triphenyl antiestrogens like tamoxifen. In summary, our results reveal that genistein is unique among the flavonoids tested, in that it has potent estrogen agonist and cell growth-inhibitory actions over a physiologically relevant concentration range.
authors.affiliation: Aeron Biotechnology, Inc., San Leandro, CA 94577, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Zava
authors.forename: G
authors.initials: G
authors.lastname: Duwe
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology; D001940:Breast / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology* / Q000503:physiopathology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002839:Chromans / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000502:physiology; D060754:Equol; D004958:Estradiol / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology; D004968:Estrogens, Non-Steroidal / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005419:Flavonoids / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology*; D019833:Genistein; D006801:Humans; D007529:Isoflavones / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology*; D044949:Kaempferols; D048789:Phytoestrogens; D028321:Plant Preparations; D011485:Protein Binding; D011794:Quercetin / Q000031:analogs & derivatives / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000032:analysis / Q000378:metabolism; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: C007610:4',7-dihydroxy-3,4-dihydroisoflavone; D016588:Anticarcinogenic Agents; D002839:Chromans; D004273:DNA, Neoplasm; D004965:Estrogen Antagonists; D004968:Estrogens, Non-Steroidal; D005419:Flavonoids; D007529:Isoflavones; D044949:Kaempferols; D048789:Phytoestrogens; D028321:Plant Preparations; D011960:Receptors, Estrogen; D013629:Tamoxifen; C016601:afimoxifene; D004958:Estradiol; D060754:Equol; C006552:kaempferol; D011794:Quercetin; D019833:Genistein