p53 and p21WAF1/CIP1 overexpression at the invasive front of lower lip squamous cell carcinoma.
BACKGROUND
Lower lip squamous cell carcinoma (LLSCC) is an oral cancer that has distinct epidemiology and etiopathogenesis. Although risk factors for this neoplasia are acknowledged, few studies have investigated the molecular basis of its development and behavior.


METHODS
Expression of p53 and p21(WAF1/CIP1) was examined by immunohistochemistry of archived tissue from 21 specimens of LLSCC. Differences in this expression between the whole tumor (WT) and the invasive front (IF) as well as correlation between p53 and p21(WAF1/CIP1) expression were analyzed.


RESULTS
p53 and p21(WAF1/CIP1) were overexpressed at the IF of LLSCC. The expression of both proteins was higher at IF than at WT. No correlation was observed between p53 and p21(WAF1/CIP1) expression.


CONCLUSIONS
Our results indicate that p53 and p21(WAF1/CIP1) overexpression is important in LLSCC pathogenesis, reinforce that IF is the most important area for tumor behavior, and support that p53-independent mechanisms should be involved in the expression of p21(WAF1/CIP1).
Horta
Martinho Campolina Rebello
MC
School of Dentistry, Pontifical Catholic University of Minas Gerais, Belo Horizonte, MG, Brazil. martinhohorta@pucminas.br
de Assis
Luis Alpino Prandini
LA
de Souza
Antonio Francisco
AF
de Araújo
Vera Cavalcanti
VC
Gomez
Ricardo Santiago
RS
Aguiar
Maria Cássia Ferreira
MC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000201:enzymology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis*; D004268:DNA-Binding Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008048:Lip Neoplasms / Q000737:chemistry* / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
D050759:Cyclin-Dependent Kinase Inhibitor p21; D004268:DNA-Binding Proteins; C478985:PDRG1 protein, human