The induction of prostaglandin E2 production, interleukin-6 production, cell cycle arrest, and cytotoxicity in primary oral keratinocytes and KB cancer cells by areca nut ingredients is differentially regulated by MEK/ERK activation
Journal
Journal of Biological Chemistry
Journal Volume
279
Journal Issue
49
Pages
50676-50683
Date Issued
2004
Author(s)
Chang M.-C.
Wu H.-L.
Lee P.-H.
Hahn L.-J.
Abstract
There are about 200-600 million betel quid (BQ) chewers in the world. BQ chewing is one of the major risk factor of hepatocarcinoma, oropharyngeal, and esophagus cancers in Taiwan, India, and Southeast Asian countries. Thus, the precise molecular mechanisms deserve investigation. We used cultured primary keratinocytes and KB cells, RT-PCR, flow cytometry, Western blotting, and ELISA to evaluate whether alterations in early gene expression is crucial in the carcinogenic processes of BQ. We observed the induction of c-Fos mRNA expression in human gingival keratinocyte (GK) and KB carcinoma cells by areca nut (AN) extract and arecoline. A maximal increment in c-fos gene expression was shown at about 30 min after challenge. AN extract (100-800 μg/ml) and arecoline (0.1-0.8 mM) also stimulated ERK1/ERK2 phosphorylation with a maximal stimulation at 5-10 min of exposure. Pretreatment by U0126 (30 μM), a MEK inhibitor, markedly inhibited the c-Fos, cyclooxygenase-2 (COX-2), and IL-6 mRNA expression of the KB epithelial cells. In addition, U0126 and PD98059 (50 μM) also decreased AN extract- and arecoline-associated PGE2 and IL-6 production in GK and KB cells. However, U0126 by itself arrested the cells in G0/G1 phase, but was not able to prevent AN- and arecoline-induced cell death or apoptosis. In contrast, U0126 enhanced the AN-induced apoptosis of KB cells. AN ingredients thus play a significant role in the pathogenesis of oropharyngeal cancer by activation of MEK1/ERK/c-Fos pathway, which promotes keratinocyte inflammation, cell survival, and affects cell cycle progression.
SDGs
Other Subjects
Cells; Mastication; Tumors; Molecular mechanisms; Pathogenesis; Phosphorylation; Toxicity; 1,4 diamino 1,4 bis(2 aminophenylthio) 2,3 dicyanobutadiene; 2 (2 amino 3 methoxyphenyl)chromone; arecoline; cyclooxygenase 2; interleukin 6; messenger RNA; mitogen activated protein kinase 1; plant extract; prostaglandin E2; protein c fos; arecoline; cyclooxygenase 2; enzyme inhibitor; interleukin 6; isoenzyme; membrane protein; messenger RNA; mitogen activated protein kinase 1; mitogen activated protein kinase 3; mitogen activated protein kinase kinase 1; plant extract; prostaglandin E2; prostaglandin synthase; protein c fos; PTGS2 protein, human; apoptosis; article; betel nut; carcinogenesis; cell cycle G0 phase; cell cycle G1 phase; cell strain KB; concentration response; controlled study; cytokine production; cytotoxicity; dose time effect relation; enzyme activation; enzyme inhibition; enzyme linked immunosorbent assay; enzyme phosphorylation; flow cytometry; human; human cell; mitosis inhibition; mouth mucosa; oropharynx cancer; priority journal; prostaglandin synthesis; protein expression; regulatory mechanism; reverse transcription polymerase chain reaction; Western blotting; biosynthesis; cell culture; cell cycle; cell survival; dose response; gene expression regulation; inflammation; keratinocyte; kinetics; metabolism; mouth; mouth tumor; phosphorylation; plant; time; tumor cell line; upregulation; Areca catechu; Piper betel; Apoptosis; Areca; Arecoline; Blotting, Western; Cell Cycle; Cell Line, Tumor; Cell Survival; Cells, Cultured; Cyclooxygenase 2; Dinoprostone; Dose-Response Relationship, Drug; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; G0 Phase; G1 Phase; Gene Expression Regulation, Neoplastic; Humans; Inflammation; Interleukin-6; Isoenzymes; KB Cells; Keratinocytes; Kinetics; MAP Kinase Kinase 1; Membrane Proteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mouth; Mouth Neoplasms; Phosphorylation; Plant Components; Plant Extracts; Prostaglandin-Endoperoxide Synthases; Proto-Oncogene Proteins c-fos; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Up-Regulation
Type
journal article