title: Genomic instability in non-neoplastic oral mucosa cells can predict risk during 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis.
abstract: 4-Nitroquinoline 1-oxide (4NQO)-induced rat tongue carcinogenesis is a useful model for studying oral squamous cell carcinoma. The aim of this study was to investigate the level of DNA damage induced by 4NQO in oral mucosa cells by the single cell gel (comet) assay. Male Wistar rats were distributed into three groups of 10 animals each and treated with 50 ppm 4NQO solution by drinking water for 4, 12 or 20 weeks. Ten animals were used as negative control. Statistically significant increase of DNA damage was observed in non-neoplastic oral cells at four weeks of 4NQO administration when compared with control (P < 0.05). The level of DNA damage was directly associated with the severity of histological changes. The results suggest that histologically normal tissue is able to harbor genetically unstable cells contributing to the initiation of oral carcinogenesis. Genomic instability appears to be associated with the risk and progression of oral cancer.
authors.affiliation: Departamento de Patologia, Núcleo de Avaliação Toxicogenética e Cancerígena, TOXICAN, Faculdade de Medicina de Botucatu, UNESP, Distrito de Rubião Jr s/n, 18618 000, SP, Brazil. ak92@hotmail.com
authors.forename: Daniel Araki
authors.initials: DA
authors.lastname: Ribeiro
authors.forename: Daisy Maria
authors.initials: DM
authors.lastname: Fávero Salvadori
authors.forename: Renata Nunes
authors.initials: RN
authors.lastname: da Silva
authors.forename: Bruno
authors.initials: B
authors.lastname: Ribeiro Darros
authors.forename: Mariangela Esther
authors.initials: ME
authors.lastname: Alencar Marques
mesh_terms: D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000473:pathology; D020552:Comet Assay / Q000379:methods; D004249:DNA Damage; D004273:DNA, Neoplasm / Q000235:genetics; D018450:Disease Progression; D042822:Genomic Instability; D008297:Male; D009061:Mouth Mucosa / Q000187:drug effects* / Q000473:pathology; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D014062:Tongue Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm; D015112:4-Nitroquinoline-1-oxide