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Chronic hepatitis C virus (HCV) infection is a worldwide threat to public health. Toll-like receptor 8 (TLR8) is critical for eliminating RNA viruses, and variation within the TLR8 gene may alter the function of TLR8 in response to HCV infection. Our previous study demonstrated that the TLR8-129G>C (rs3764879) and TLR8+1G>A (rs3764880) variants were in complete linkage disequilibrium, and that the frequency of TLR8-129C/+1A was significantly higher in male patients with HCV infection compared with the healthy controls. In the present study, we found that the promoter activity of TLR8-129G was higher than that of TLR8-129C in THP-1 cells. Moreover, TLR8-129G mRNA stability and competitive DNA-binding ability were significantly lower than that of TLR8-129C. To investigate the functional effects of TLR8 polymorphisms, we compared the nuclear factor- κB (NF- κB)-driven luciferase activity in HEK293 cells transfected with the TLR8 variants. TLR8+1A plasmids induced less NF- κB signalling than did those transfected with TLR8+1G after 20 μ m CL075 ( P = 0·011) stimulation. We also analysed the mRNA expression and cytokine production in whole blood and monocytes from people of various genotypes stimulated ex vivo by the interferon- γ and TLR7/8 agonist CL075, R848. TLR8 expression in CD14+ cells derived from volunteers with TLR8-129G/+1G was significantly higher than that derived from TLR8-129C /+1A, and interleukin-12p40 production was higher in volunteers with TLR8-129G/+1G after stimulation. The data indicate that variations in TLR8 genes may modulate immune responses during HCV infection. [ABSTRACT FROM AUTHOR]

Little is known about any consequences of swallowing tobacco-free betel-quid (TF-BQ) juice/remnants following chewing and its carcinogenic impact on the upper aerodigestive tract (UADT) to gastrointestinal tract (GIT). We investigated the neoplastic impact of TF-BQ on different anatomical locations along UADT and GIT, and differences according to their histological categories. We conducted a multicenter case-control study examining patients with 2,163 pathology-proven UADT and GIT cancers, comparing them with 2,250 control subjects. Generalized additive models, piecewise regression and polytomous logistic models were applied to identify possible dose-dependent structures and cancer risks. Contrary to nonsignificant GIT-adenocarcinoma risk (aOR = 0.9), TF-BQ users experienced a 1.7- to 16.2-fold higher risk of UADT-squamous cell carcinomas than nonusers, with the peak risk discovered in oral neoplasms. We separately observed a curvilinear and linear TF-BQ dose-risk relationship in oral/pharyngeal/esophageal and laryngeal cancers. Chewers of betel inflorescence were generally at a greater UADT cancer risk. A higher first-piecewise increased risk of esophageal cancer was recognized among areca-fluid swallowers than among nonswallowers (continuous aOR = 1.12 vs. 1.03). TF-BQ use accounted for 66.1-78.7% and 17.8-33.2% of the cases of oral/pharyngeal and esophageal/laryngeal cancers, respectively. However, a reduction from heavy TF-BQ consumption to low-to-moderate consumption only reduced 11.3-34.6% of etiologic fraction of oral/pharyngeal cancers. Alcohol supra-additively modified the risk of TF-BQ in determining the development of oral, pharyngeal and esophageal cancers. In conclusion, the interplay of TF-BQ and alcohol/tobacco use, combined with how chewing habit is practiced, influences carcinogenic consequences on anatomically diverse sites of UADT and GIT cancers, and histologically different types. [ABSTRACT FROM AUTHOR]

J Oral Pathol Med (2011) 40: 684-692 Background: Recognition of how risk factors affect the age when cancers are first diagnosed may help to establish more appropriate cancer screening and preventive strategies. Methods: To investigate the independent and synergistic effects of alcohol, tobacco-free betel-quid (TF-BQ), and cigarette use on diagnosis age and dissemination of upper aerodigestive tract squamous cell carcinoma (UADT-SCC), we recruited pathology-proven 1522 patients with UADT-SCC for study. Results: A 49-, 53-, 57-, and 62-year-old stepwise older median age at carcinoma diagnosis was, respectively, found among patients with oral, pharyngeal, esophageal, and laryngeal cancer. Oral cavity (53.2%) and larynx (11.6%) were separately the dominant and recessive sites where the UADT-SCC occurred. Although alcohol and tobacco bestowed increased risks of earlier tumor occurrence only for oral/pharyngeal and oral cancers, respectively, TF-BQ was consistently observed to confer elevated age-associated risks for each UADT-SCC [adjusted hazard ratio (aHR) = 1.6-2.3]. Alcohol and TF-BQ joint consumers experienced a stepwise increased cumulative risk (CR) of contracting carcinomas of the larynx (46.2%), esophagus (47.5%), pharynx (53.5%), and oral cavity (60.5-71.0%), with >68% of CRs found among drinkers who started chewing before age 20. Alcohol + Betel + Cigarette and Alcohol + Betel users exhibi-ted earlier diagnosis ages than non-users: 10 years ahead for oral cancer, 7, 17, and 12 years earlier for pharyngeal, esophageal, and laryngeal cancers. Noticeably, higher cumulative cancer risks regarding earlier tumor occurrence were correspondingly identified for these users aged 43, 49, 43, and 44 upward. Conclusions: Tobacco-free betel-quid, in conjunction with alcohol and/or tobacco consumption, impacts early cancer occurrence for specific UADT-SCC and influences tumor site incidence pattern of these neoplasms. [ABSTRACT FROM AUTHOR]