title: Estrogens and cell-cycle regulation in breast cancer.
abstract: Clinical and experimental data have established that the leading cause of sporadic female breast cancer is exposure to estrogens, predominantly 17beta-estradiol. Recent advances in the understanding of cell-cycle control mechanisms have been applied to outline the molecular mechanisms through which estrogens regulate the cell cycle in cultured breast cancer cells, in particular, in MCF-7 cells. Here, we discuss how estrogens exert control over several key G1 phase cell-cycle regulators, namely cyclin D1, Myc, Cdk2, Cdk4, Cdk inhibitors and Cdc25A. Although the molecular mechanisms underlying estrogenic regulation of G1 phase regulators are far from clear, current evidence indicates that estrogens might regulate several key molecules required for S phase entry, this regulation being independent of cell-cycle transit per se.
authors.affiliation: Dept of OB/GYN, Graduate School of Medicine, University of Tennessee, Knoxville, TN 37920, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Foster
authors.forename: D C
authors.initials: DC
authors.lastname: Henley
authors.forename: S
authors.initials: S
authors.lastname: Ahamed
authors.forename: J
authors.initials: J
authors.lastname: Wimalasena
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D042846:CDC2-CDC28 Kinases; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016213:Cyclins / Q000235:genetics / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000502:physiology*; D005260:Female; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D016213:Cyclins; D004967:Estrogens; D004958:Estradiol; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases