RESUMO
Consumption of green tea (GT) extracts or purified catechins has shown the ability to prevent oral and other cancers and inhibit cancer progression in rodent models, but the evidence for this in humans is mixed. Working with humans, we sought to understand the source of variable responses to GT by examining its effects on oral epithelium. Lingual epithelial RNA and lingual and gingival microbiota were measured before and after 4 weeks of exposure in tobacco smokers, whom are at high risk of oral cancer. GT consumption had on average inconsistent effects on miRNA expression in the oral epithelium. Only analysis that examined paired miRNAs, showing changed and coordinated expression with GT exposure, provided evidence for a GT effect on miRNAs, identifying miRNAs co-expressed with two hubs, miR-181a-5p and 301a-3p. An examination of the microbiome on cancer prone lingual mucosa, in contrast, showed clear shifts in the relative abundance of Streptococcus and Staphylococcus, and other genera after GT exposure. These data support the idea that tea consumption can consistently change oral bacteria in humans, which may affect carcinogenesis, but argue that GT effects on oral epithelial miRNA expression in humans vary between individuals.
Assuntos
Antioxidantes/administração & dosagem , MicroRNAs/genética , Mucosa Bucal/efeitos dos fármacos , Neoplasias Bucais/prevenção & controle , Chá/química , Adulto , Antioxidantes/química , Carcinogênese/efeitos dos fármacos , Catequina/administração & dosagem , Epitélio/efeitos dos fármacos , Epitélio/microbiologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Gengiva/microbiologia , Humanos , Masculino , MicroRNAs/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Microbiota/genética , Pessoa de Meia-Idade , Mucosa Bucal/microbiologia , Neoplasias Bucais/genética , Neoplasias Bucais/microbiologia , Fumantes , Staphylococcus/efeitos dos fármacos , Staphylococcus/patogenicidade , Streptococcus/efeitos dos fármacos , Streptococcus/patogenicidade , Adulto JovemRESUMO
Seventeen oral epidermoid carcinomas, three oral papillomas, and 17 normal gingival tissues were tested for the presence of human papillomavirus (HPV) types 6, 11, 16, and 18 sequences by Southern blot hybridization. Episomal HPV-16 sequences in various amounts were detected in 76.4% of the oral carcinomas and in all three cases of papilloma. However, only one of the 17 normal tissues was HPV positive with an unknown type. None of the samples contained HPV-6, -11, or -18 sequences. Examination of the habits of the patients showed that 59% of the patients were betel quid chewers and 82% were smokers. Thus, the concurrent incidence of HPV infection and betal quid chewing and/or smoking habits in oral carcinoma patients observed in Taiwan is consistent with the view that both viral and chemical factors may be involved in the process of carcinogenesis.