title: The effect of resveratrol and its methylthio-derivatives on NF-κB and AP-1 signaling pathways in HaCaT keratinocytes.
abstract: BACKGROUND
  Resveratrol is a natural stilbene derivative whose chemopreventive activity has been well established. Our previous studies have shown that modification of the stilbene backbone with the methylthio group may influence selectivity and inhibitory potency toward P450 isozymes. The aim of this study was to further investigate the mechanism of their potential chemopreventive activity by evaluating the effect of two 4'-methylthio-trans-stilbene derivatives possessing one (3-M-4'-MTS; S2) and two (3,5-DM-4'-MTS; S5) additional methoxy groups on constitutive nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activation in immortalized human HaCaT keratinocytes.
  
  
  METHODS
  The synthesis of MTS was performed as described earlier. Translocation of NF-κB and AP-1 was evaluated by Western blot analysis. Binding of p65 (NF-κB) and c-Jun and c-Fos subunits (AP-1) to consensus oligonucleotide was assessed by ELISA. Real-time PCR and Western blot were used to evaluate COX-2 and iNOS expression.
  
  
  RESULTS
  We found differential modulation of signaling pathways depending on the stilbene structure after 24h of cells treatment. The S2 compound, in contrast to S5 and resveratrol, significantly reduced NF-κB activation by blocking the translocation of the p65 subunit to the nucleus, and decreasing IκB kinase activity. All compounds, but particularly S5, increased c-Jun binding to the AP-1 consensus sequence, while c-Fos binding was not affected.
  
  
  CONCLUSIONS
  We conclude that methylthiostilbenes differently modulate constitutive signal transduction pathways in HaCaT cells. These observations should be taken into account in designing new stilbene derivatives with potential chemopreventive activity.
authors.affiliation: Department of Pharmaceutical Biochemistry, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Szaefer
authors.affiliation: Department of Pharmaceutical Biochemistry, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Cichocki
authors.affiliation: Department of Pharmaceutical Biochemistry, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Violetta
authors.initials: V
authors.lastname: Krajka-Kuźniak
authors.affiliation: Department of Chemical Technology of Drugs, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Stefański
authors.affiliation: Department of Inorganic and Analytical Chemistry, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Sobiak
authors.affiliation: Department of Pharmaceutical Biochemistry, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Licznerska
authors.affiliation: Department of Pharmaceutical Biochemistry, Poznań University of Medical Sciences, Poznań, Poland. Electronic address: baerw@ump.edu.pl.
authors.forename: Wanda
authors.initials: W
authors.lastname: Baer-Dubowska
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D000077185:Resveratrol; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D016328:NF-kappa B; D016760:Proto-Oncogene Proteins c-fos; D013267:Stilbenes; D018808:Transcription Factor AP-1; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D000077185:Resveratrol
keywords: AP-1; Human HaCaT keratinocytes; Methylthiostilbenes; NF-κB; Resveratrol