1. Terrein inhibits keratinocyte proliferation via ERK inactivation and G2/M cell cycle arrest.
- Author
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Kim DS, Lee HK, Park SH, Lee S, Ryoo IJ, Kim WG, Yoo ID, Na JI, Kwon SB, and Park KC
- Subjects
- Butadienes pharmacology, CDC2 Protein Kinase metabolism, Cell Cycle physiology, Cell Survival drug effects, Cells, Cultured, Cyclin B metabolism, Cyclin B1, Cyclin-Dependent Kinase Inhibitor p27 metabolism, Extracellular Signal-Regulated MAP Kinases antagonists & inhibitors, Extracellular Signal-Regulated MAP Kinases physiology, Flow Cytometry, Humans, Keratinocytes cytology, Keratinocytes physiology, Nitriles pharmacology, Phosphorylation, Protein Precursors metabolism, Signal Transduction physiology, Cell Cycle drug effects, Cell Proliferation drug effects, Cyclopentanes pharmacology, Extracellular Signal-Regulated MAP Kinases metabolism, Keratinocytes drug effects
- 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.
- Published
- 2008
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