title: Areca nut components affect COX-2, cyclin B1/cdc25C and keratin expression, PGE2 production in keratinocyte is related to reactive oxygen species, CYP1A1, Src, EGFR and Ras signaling.
abstract: OBJECTIVE
  Chewing of betel quid (BQ) increases the risk of oral cancer and oral submucous fibrosis (OSF), possibly by BQ-induced toxicity and induction of inflammatory response in oral mucosa.
  
  
  METHODS
  Primary gingival keratinocytes (GK cells) were exposed to areca nut (AN) components with/without inhibitors. Cytotoxicity was measured by 3-(4,5-dimethyl- thiazol- 2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. mRNA and protein expression was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. PGE2/PGF2α production was measured by enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Areca nut extract (ANE) stimulated PGE2/PGF2α production, and upregulated the expression of cyclooxygenase-2 (COX-2), cytochrome P450 1A1 (CYP1A1) and hemeoxygenase-1 (HO-1), but inhibited expression of keratin 5/14, cyclinB1 and cdc25C in GK cells. ANE also activated epidermal growth factor receptor (EGFR), Src and Ras signaling pathways. ANE-induced COX-2, keratin 5, keratin 14 and cdc25C expression as well as PGE2 production were differentially regulated by α-naphthoflavone (a CYP 1A1/1A2 inhibitor), PD153035 (EGFR inhibitor), pp2 (Src inhibitor), and manumycin A (a Ras inhibitor). ANE-induced PGE2 production was suppressed by piper betle leaf (PBL) extract and hydroxychavicol (two major BQ components), dicoumarol (a
  Quinone Oxidoreductase--NQO1 inhibitor) and curcumin. ANE-induced cytotoxicity was inhibited by catalase and enhanced by dicoumarol, suggesting that AN components may contribute to the pathogenesis of OSF and oral cancer via induction of aberrant differentiation, cytotoxicity, COX-2 expression, and PGE2/PGF2α production.
  
  
  CONCLUSIONS
  CYP4501A1, reactive oxygen species (ROS), EGFR, Src and Ras signaling pathways could all play a role in ANE-induced pathogenesis of oral cancer. Addition of PBL into BQ and curcumin consumption could inhibit the ANE-induced inflammatory response.
authors: Team of Biomedical Science, Chang-Gung University of Science and Technology, Kwei-Shan, Taoyuan, Taiwan.
authors: Mei-Chi
authors: MC
authors: Chang
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Yi-Jane
authors: YJ
authors: Chen
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Hsiao-Hua
authors: HH
authors: Chang
authors: Department of Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors: Chiu-Po
authors: CP
authors: Chan
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Chien-Yang
authors: CY
authors: Yeh
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Yin-Lin
authors: YL
authors: Wang
authors: Team of Biomedical Science, Chang-Gung University of Science and Technology, Kwei-Shan, Taoyuan, Taiwan.
authors: Ru-Hsiu
authors: RH
authors: Cheng
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Liang-Jiunn
authors: LJ
authors: Hahn
authors: Laboratory of Pharmacology, Toxicology and Chemical Carcinogenesis, School of Dentistry and Department of Dentistry, National Taiwan University Hospital; and National Taiwan University Medical College, Taipei, Taiwan.
authors: Jiiang-Huei
authors: JH
authors: Jeng
mesh_terms: D001114:Areca / Q000737:chemistry*; D002478:Cells, Cultured; D003474:Curcumin / Q000494:pharmacology; D056744:Cyclin B1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D001728:Dicumarol / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis; D066246:ErbB Receptors / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects*; D005881:Gingiva / Q000473:pathology; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D007633:Keratins / Q000235:genetics / Q000378:metabolism; D010936:Plant Extracts / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: C534699:CCNB1 protein, human; D056744:Cyclin B1; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D007633:Keratins; D001728:Dicumarol; C569463:CYP1A1 protein, human; D019363:Cytochrome P-450 CYP1A1; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; D019061:src-Family Kinases; C517009:CDC25C protein, human; D020687:cdc25 Phosphatases; D018631:ras Proteins; D003474:Curcumin; D015232:Dinoprostone