title: Transcriptional repression of miR-34 family contributes to p63-mediated cell cycle progression in epidermal cells.
abstract: p63, a p53 family member, is highly expressed in the basal proliferative compartment of the epidermis and its expression has been correlated with the growth ability and regenerative capacity of keratinocytes. In this study we report a mechanism through which p63 maintains cell cycle progression by directly repressing miR-34a and miR-34c. In the absence of p63, increased levels of miR-34a and miR-34c were observed in primary keratinocytes and in embryonic skin, with concomitant G1-phase arrest and inhibition of the cell cycle regulators cyclin D1 and cyclin-dependent kinase 4 (Cdk4). p63 directly bound to p53-consensus sites in both miR-34a and miR-34c regulatory regions and inhibited their activity. Concomitant downregulation of miR-34a and miR-34c substantially restored cell cycle progression and expression of cyclin D1 and Cdk4. Our data indicate that specific miR-34 family members have a significant role downstream of p63 in controlling epidermal cell proliferation.
authors.affiliation: CEINGE Biotecnologie Avanzate, Napoli, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Antonini
authors.forename: Monia T
authors.initials: MT
authors.lastname: Russo
authors.forename: Laura
authors.initials: L
authors.lastname: De Rosa
authors.forename: Marisa
authors.initials: M
authors.lastname: Gorrese
authors.forename: Luigi
authors.initials: L
authors.lastname: Del Vecchio
authors.forename: Caterina
authors.initials: C
authors.lastname: Missero
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics / Q000378:metabolism; D000078404:Epidermal Cells; D004817:Epidermis / Q000196:embryology / Q000502:physiology; D016193:G1 Phase / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D035683:MicroRNAs / Q000235:genetics*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: C530105:Ccnd1 protein, mouse; D035683:MicroRNAs; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D015534:Trans-Activators; C486419:Trp63 protein, mouse; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1; C495902:Cdk4 protein, mouse; D051358:Cyclin-Dependent Kinase 4