title: Insulin-like growth factor binding protein-3 gene methylation and protein expression in gastric adenocarcinoma.
abstract: OBJECTIVE
  The aim of this study was to evaluate IGFBP-3 protein expression, its correlation with gene promoter methylation pattern in gastric carcinogenesis and with clinicopathological characteristics.
  
  
  METHODS
  Forty-three normal gastric mucosa and 94 adenocarcinoma samples were investigated through methylation specific PCR, after bisulfite modification. Immunohistochemistry was analyzed using peroxidase in 54 gastric cancer and 20 normal gastric mucosa samples.
  
  
  RESULTS
  IGFBP-3 expression was higher in tumor samples than in normal mucosa (p<0.0001). Intestinal type presented a higher frequency of protein expression than diffuse type (p=0.0412). Methylation frequency of IGFBP-3 promoter in gastric samples revealed, respectively, 95.7% and 97.7% in neoplastic and non-neoplastic samples. The frequency of IGFBP-3 methylation did not differ between tumor and normal samples (95.7% versus 97.7%, p=0.7810). We did not observe a significant correlation between IGFBP-3 promoter methylation and protein expression.
  
  
  CONCLUSIONS
  In summary, our study did not observe any influence of IGFBP-3 promoter methylation on protein expression. Moreover we propose that IGFBP-3 immunostaining in gastric tissue may be a useful marker for malignancy.
authors.affiliation: Disciplina de Genética, Departamento de Morfologia e Genética, Universidade Federal de São Paulo, SP, Brazil.
authors.forename: Carolina Oliveira
authors.initials: CO
authors.lastname: Gigek
authors.forename: Mariana Ferreira
authors.initials: MF
authors.lastname: Leal
authors.forename: Luara Carolina Frias
authors.initials: LC
authors.lastname: Lisboa
authors.forename: Patricia Natalia Oliveira
authors.initials: PN
authors.lastname: Silva
authors.forename: Elizabeth Suchi
authors.initials: ES
authors.lastname: Chen
authors.forename: Eleonidas Moura
authors.initials: EM
authors.lastname: Lima
authors.forename: Danielle Queiroz
authors.initials: DQ
authors.lastname: Calcagno
authors.forename: Paulo Pimentel
authors.initials: PP
authors.lastname: Assumpção
authors.forename: Rommel Rodriguez
authors.initials: RR
authors.lastname: Burbano
authors.forename: Marilia de Arruda Cardoso
authors.initials: Mde A
authors.lastname: Smith
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D011506:Proteins