title: Loss of tumour suppressor p16 expression in initial stages of oral oncogenesis.
abstract: BACKGROUND
  The p16 tumour suppressor gene is known to be involved in regulation of the cell cycle. p16 expression in sequential histological stages of oral squamous cell carcinoma (OSCC) formation was investigated using an experimental model of induced oral carcinogenesis in Syrian golden hamsters.
  
  
  METHODS
  Thirty-seven animals were divided into one control group (N = 7) and three experimental groups (N = 10 each) which were treated with a carcinogen and sacrificed at 10, 14 and 19 weeks after treatment. Tumour sections were studied immunohistochemically using monoclonal antibodies against p16 protein.
  
  
  RESULTS
  p16 was found significantly increased in hyperplasia, sharply decreased in dysplasia and in the subsequent stages of oral carcinogenesis.
  
  
  CONCLUSIONS
  Inactivation of p16 occurs at the early stage of oral mucosal dysplasia in the multistep process of oral tumourigenesis. Therefore, p16 may be considered as a useful prognostic marker for the progression of oral cancer.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Athens Medical School, Vas. Sofias 93 and Dim. Soutsou 1, Athens 11521, Greece. lvairakt@med.uoa.gr
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Vairaktaris
authors.forename: Christos
authors.initials: C
authors.lastname: Yapijakis
authors.forename: Amanda
authors.initials: A
authors.lastname: Psyrri
authors.forename: Sofia
authors.initials: S
authors.lastname: Spyridonidou
authors.forename: Athanasios
authors.initials: A
authors.lastname: Yannopoulos
authors.forename: Andreas
authors.initials: A
authors.lastname: Lazaris
authors.forename: Stavros
authors.initials: S
authors.lastname: Vassiliou
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Ferekidis
authors.forename: Antonis
authors.initials: A
authors.lastname: Vylliotis
authors.forename: Emeka
authors.initials: E
authors.lastname: Nkenke
authors.forename: Efstratios
authors.initials: E
authors.lastname: Patsouris
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D002273:Carcinogens; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006224:Cricetinae; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D020868:Gene Silencing; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*
chemical_list: D002273:Carcinogens; D019941:Cyclin-Dependent Kinase Inhibitor p16; D015127:9,10-Dimethyl-1,2-benzanthracene