title: Id2 gene-targeted crosstalk between Wnt and retinoid signaling regulates proliferation in human keratinocytes.
abstract: We investigated the effect of all-trans-retinoic acid (atRA) on proliferation in several human skin cell lines and found that antiproliferative potency of atRA correlated with the endogenous activity of canonical Wnt signaling. In HaCaT keratinocytes, we found that atRA significantly suppressed the expression of Id2, a member of the inhibitor of differentiation family of transcription factors that regulate cell growth and differentiation. However, no apparent change in the expression of other Wnt targets, like c-Myc or cyclin D1, was observed. Retinoid-induced Id2 gene suppression was associated with decreased levels of histone H3 and H4 acetylation and histone H3 Lys-4 methylation, and with recruitment of the LSD1 demethylase at the Wnt-response element (WRE) (TCF/LEF-binding site), in the Id2 gene promoter. None of such changes was detected at the WRE of c-Myc and cyclin D1 gene promoters. Inhibition of Id2 by short interfering RNA (siRNA) had a similar effect on the proliferation of HaCaT cells as exposure to atRA, whereas anti-beta-catenin siRNA significantly inhibited its antiproliferative effect. These data suggest that downregulation of Id2 gene expression through transcriptional convergence between Wnt and retinoid signaling pathways underlies the antiproliferative effect of retinoids in keratinocytes, and provide evidence of gene-targeted crosstalk between signaling pathways.
authors.affiliation: Department of Nuclear Signaling, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Memezawa
authors.forename: I
authors.initials: I
authors.lastname: Takada
authors.forename: K
authors.initials: K
authors.lastname: Takeyama
authors.forename: M
authors.initials: M
authors.lastname: Igarashi
authors.forename: S
authors.initials: S
authors.lastname: Ito
authors.forename: S
authors.initials: S
authors.lastname: Aiba
authors.forename: S
authors.initials: S
authors.lastname: Kato
authors.forename: A P
authors.initials: AP
authors.lastname: Kouzmenko
mesh_terms: D000107:Acetylation; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D019938:Cyclin D1 / Q000378:metabolism; D015536:Down-Regulation; D005786:Gene Expression Regulation; D056466:Histone Demethylases; D006657:Histones / Q000378:metabolism; D006801:Humans; D051797:Inhibitor of Differentiation Protein 2 / Q000037:antagonists & inhibitors / Q000235:genetics*; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020218:Response Elements; D012176:Retinoids / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*; D051153:Wnt Proteins / Q000378:metabolism*
chemical_list: D006657:Histones; C497450:ID2 protein, human; D051797:Inhibitor of Differentiation Protein 2; C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D012176:Retinoids; D051153:Wnt Proteins; D019938:Cyclin D1; D014212:Tretinoin; D056466:Histone Demethylases; C495195:KDM1A protein, human; D010089:Oxidoreductases, N-Demethylating