title: Terrein inhibits keratinocyte proliferation via ERK inactivation and G2/M cell cycle arrest.
abstract: Terrein, a fungal metabolite, has been recently shown to have a strong antiproliferative effect on skin equivalents. In the present study, we further investigated the effects of terrein on the possible signalling pathways involved in the growth inhibition of human epidermal keratinocytes by examining the regulations of extracellular signal-regulated protein kinase (ERK) and of the Akt pathway by terrein. It was observed that ERK was inactivated by terrein and that keratinocyte proliferation was inhibited, whereas Akt was unaffected. The inhibition of the ERK pathway by U0126 (a specific ERK inhibitor) also had a dose-dependent antiproliferative effect on human keratinocytes. These results indicate that ERK inhibition is involved in keratinocyte growth inhibition by terrein. Moreover, flow cytometric analysis showed that terrein inhibits DNA synthesis, as evidenced by a reduction in the S phase and an increase in the G2/M phase of the cell cycle. Thus, we next examined changes in the expressions of G2/M cell cycle-related proteins. Terrein was found to downregulate cyclin B1 and Cdc2 without Cdc2 phosphorylation, but upregulated p27(KIP1) (p27), a known inhibitor of cyclin-dependent kinase. These results suggest that terrein reduces human keratinocyte proliferation by inhibiting ERK and by decreasing the expressions of cyclin B1 and Cdc2 complex.
authors.affiliation: Department of Biochemistry, College of Medicine, Chung-Ang University, Republic of Korea.
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Seo-Hyoung
authors.initials: SH
authors.lastname: Park
authors.forename: Sangku
authors.initials: S
authors.lastname: Lee
authors.forename: In-Ja
authors.initials: IJ
authors.lastname: Ryoo
authors.forename: Won-Gon
authors.initials: WG
authors.lastname: Kim
authors.forename: Ick-Dong
authors.initials: ID
authors.lastname: Yoo
authors.forename: Jung-Im
authors.initials: JI
authors.lastname: Na
authors.forename: Sun-Bang
authors.initials: SB
authors.lastname: Kwon
authors.forename: Kyoung-Chan
authors.initials: KC
authors.lastname: Park
mesh_terms: D002070:Butadienes / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009570:Nitriles / Q000494:pharmacology; D010766:Phosphorylation; D011498:Protein Precursors / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
chemical_list: D002070:Butadienes; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D003517:Cyclopentanes; D009570:Nitriles; D011498:Protein Precursors; C113580:U 0126; D050760:Cyclin-Dependent Kinase Inhibitor p27; C439087:terrein; C032253:involucrin; D016203:CDC2 Protein Kinase; D048049:Extracellular Signal-Regulated MAP Kinases