title: KLF15 negatively regulates estrogen-induced epithelial cell proliferation by inhibition of DNA replication licensing.
abstract: In the epithelial compartment of the uterus, estradiol-17β (E(2)) induces cell proliferation while progesterone (P(4)) inhibits this response and causes differentiation of the cells. In this study, we identified the mechanism whereby E(2) and P(4) reciprocally regulate the expression of minichromosome maintenance (MCM)-2, a protein that is an essential component of the hexameric MCM-2 to 7 complex required for DNA synthesis initiation. We show in the uterine epithelium that Kruppel-like transcription (KLF) factors, KLF 4 and 15, are inversely expressed; most importantly, they bind to the Mcm2 promoter under the regulation of E(2) and P(4)E(2), respectively. After P(4)E(2) exposure and in contrast to E(2) treated mice, the Mcm2 promoter displays increased histone 3 (H3) methylation and the recruitment of histone deacetylase 1 and 3 with the concomitant deacetylation of H3. This increased methylation and decreased acetylation is associated with an inhibition of RNA polymerase II binding, indicating an inactive Mcm2 promoter following P(4)E(2) treatment. Using transient transfection assays in the Ishikawa endometrial cell line, we demonstrate that Mcm2 promoter activity is hormonally stimulated by E(2) and that KLF15 inhibits this E(2) enhanced transcription. KLF15 expression also blocks Ishikawa cell proliferation through inhibition of MCM2 protein level. Importantly, in vivo expression of KLF15 in an estrogenized uterus mimics P(4)'s action by inhibiting E(2)-induced uterine epithelial MCM-2 expression and DNA synthesis. KLF15 is therefore a downstream physiological mediator of progesterone's cell cycle inhibitory action in the uterine epithelium.
authors.affiliation: Department of Developmental and Molecular Biology, Specialized Cooperative Center for the Study of Reproduction and Infertility Research, Albert Einstein College of Medicine, NY 10461, USA.
authors.forename: Sanhita
authors.initials: S
authors.lastname: Ray
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Pollard
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000818:Animals; D001943:Breast Neoplasms; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000187:drug effects / Q000502:physiology; D004261:DNA Replication / Q000187:drug effects / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004717:Endometrium / Q000166:cytology*; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D004958:Estradiol / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006657:Histones / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D064111:Minichromosome Maintenance Complex Component 2; D009687:Nuclear Proteins / Q000235:genetics; D010052:Ovariectomy; D061251:Primary Cell Culture; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000502:physiology; D012319:RNA Polymerase II / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D006657:Histones; C467418:Klf15 protein, mouse; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D011374:Progesterone; D004958:Estradiol; D012319:RNA Polymerase II; D064111:Minichromosome Maintenance Complex Component 2