title: p53 and p21WAF1/CIP1 overexpression at the invasive front of lower lip squamous cell carcinoma.
abstract: 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).
authors.affiliation: School of Dentistry, Pontifical Catholic University of Minas Gerais, Belo Horizonte, MG, Brazil. martinhohorta@pucminas.br
authors.forename: Martinho Campolina Rebello
authors.initials: MC
authors.lastname: Horta
authors.forename: Luis Alpino Prandini
authors.initials: LA
authors.lastname: de Assis
authors.forename: Antonio Francisco
authors.initials: AF
authors.lastname: de Souza
authors.forename: Vera Cavalcanti
authors.initials: VC
authors.lastname: de Araújo
authors.forename: Ricardo Santiago
authors.initials: RS
authors.lastname: Gomez
authors.forename: Maria Cássia Ferreira
authors.initials: MC
authors.lastname: Aguiar
mesh_terms: 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
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D004268:DNA-Binding Proteins; C478985:PDRG1 protein, human