Insulin-like growth factor binding protein-3 gene methylation and protein expression in gastric adenocarcinoma.
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.
Gigek
Carolina Oliveira
CO
Disciplina de Genética, Departamento de Morfologia e Genética, Universidade Federal de São Paulo, SP, Brazil.
Leal
Mariana Ferreira
MF
Lisboa
Luara Carolina Frias
LC
Silva
Patricia Natalia Oliveira
PN
Chen
Elizabeth Suchi
ES
Lima
Eleonidas Moura
EM
Calcagno
Danielle Queiroz
DQ
Assumpção
Paulo Pimentel
PP
Burbano
Rommel Rodriguez
RR
Smith
Marilia de Arruda Cardoso
Mde A
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
D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D011506:Proteins