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

AimsChewing 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.MethodsPrimary 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.ResultsAreca 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 NAD(P)H: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/PGF2αproduction.ConclusionsCYP4501A1, 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.

Protein expression of CYP1A1, CYP1B1, ALDH1A1, and ALDH2 in young patients with oral squamous cell carcinoma

“…The aberrant growth, differentiation, and inflammation of gingival keratinocytes induced by these pathways may contribute to the pathogenesis of oral submucous fibrosis and OSCC. 18 In the present study, CYP1A1 was only expressed in peripheral cells of the invasive front near blood vessels and nerve fibres, suggesting that this enzyme contributes to tumour aggressiveness in both groups.…”

Cytotoxicity and transformation of C3H10T1/2 cells induced by areca nut components

“…productions that are potential tumor promoters. 7,12,21,30,31 Prostaglandin and ROS have been demonstrated to promote the transformation of carcinogen and radiation-treated C3H10T1/2 cells. 32,33 Moreover, we found that ANE markedly stimulated the transformation of C3H10T1/2 cells, especially in the presence of the tumor promoter, TPA.…”

Prevalence of Oral Submucous Fibrosis and Periodontal Health Status in Patients Chewing Gutka From Bihar Region

“…The areca nut component of betel quid plays a major role in the pathogenesis of oral submucous fibrosis. [10,11,12,13] In a 2004 study, a clear dose-dependent relationship was observed for both frequency and duration of chewing areca nut (without tobacco) in the development of oral submucous fibrosis. [14] Smoking and alcohol consumption alone, habits common to areca nut chewers, have been found to have no effect in the development of oral submucous fibrosis, [15] but their addition to areca nut chewing can be a risk for oral submucous fibrosis.…”