Loss of tumour suppressor p16 expression in initial stages of oral oncogenesis.
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.
Vairaktaris
Eleftherios
E
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
Yapijakis
Christos
C
Psyrri
Amanda
A
Spyridonidou
Sofia
S
Yannopoulos
Athanasios
A
Lazaris
Andreas
A
Vassiliou
Stavros
S
Ferekidis
Eleftherios
E
Vylliotis
Antonis
A
Nkenke
Emeka
E
Patsouris
Efstratios
E
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*
D002273:Carcinogens; D019941:Cyclin-Dependent Kinase Inhibitor p16; D015127:9,10-Dimethyl-1,2-benzanthracene