Impact of eugenol and isoeugenol on AhR translocation, target gene expression, and proliferation in human HaCaT keratinocytes.
The phenolic derivatives eugenol and isoeugenol, which are naturally found in essential oils of different spices, are commonly used as fragrances. Recently data demonstrated that growth suppression produced by these substances occurs in keratinocytes and that the effects may be mediated via aryl hydrocarbon receptor (AhR) interactions. In this study the effects of eugenol and isoeugenol were determined on intracellular localization of AhR, AhR target gene expression, AhR-dependent cell cycle regulation, and proliferation in HaCaT cells. Both compounds produced a rapid and marked translocation of AhR into the nucleus, induced the expression of the AhR target genes cytochrome P-450 1A1 (CYP1A1) and AhR repressor (AhRR), and inhibited proliferation of HaCaT cells. Among the G(1) phase cell cycle-related proteins, levels of the retinoblastoma protein (RB), which is known to interact with AhR, and levels of the cyclin dependent kinase (CDK) 6 were reduced by eugenol and isoeugenol, whereas steady-state levels of CDK2 and CDK4 remained unaffected. Protein levels of CDK inhibitor (CKI) p27(KIP1), known to be modulated in an AhR-dependent manner, were increased after treatment with both substances. In conclusion, data show that the antiproliferative properties of eugenol and isoeugenol in HaCaT cells are mediated through AhR, and thereby the molecular mechanisms of action in these cells were identified for the first time in this study.
Department of Environmental Toxicology, University of Trier, Trier, Germany.
Michaela
M
Kalmes
Brunhilde
B
Blömeke
D000963:Antimetabolites; D015153:Blotting, Western; D001973:Bromodeoxyuridine; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D005054:Eugenol / Q000031:analogs & derivatives* / Q000494:pharmacology; D016193:G1 Phase / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000187:drug effects*; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018336:Receptors, Aryl Hydrocarbon / Q000187:drug effects* / Q000235:genetics; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D016196:S Phase / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013778:Tetrazolium Salts
C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D000963:Antimetabolites; D018797:Cell Cycle Proteins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D013778:Tetrazolium Salts; D005054:Eugenol; C036643:isoeugenol; D019363:Cytochrome P-450 CYP1A1; D001973:Bromodeoxyuridine