Study On E-cadherin Gene Promoter Hypermethylation And Its Protein Expression In Primary Adenocarcinomas Of The Small Bowel

Objective: To investigate the methylation status of E-cadherin and the expression of E-cadherin in human small bowel adenocarcinomas(SBAC), and the association of these findings with clinico-pathological characteristics.Methods: Methylation-specific PCR (MSP) assay was performed in 36 primary SBAC and the paired adjacent normal tissues.This was correlated with expression at the protein level using immunohistochemistry(IHC).Date were associated with clinico-pathological characteristics.Results:①The hypermethylation frequency of E-cadherin was 38.9% in cancerous tissues, 8.3% in adjacent normal tissues(P <0. 01);②The positive rate of E-cadherin expression was 41.7% in cancerous tissues, 97.2% in adjacent normal tissues(P <0. 01);③Hypermethylation of the 14 cases of SBAC,12 cases of missing protein expression,unmethylation of the 22 cases of SBAC,9 cases of missing protein expression. Hypermethylation of E-cadherin was correlated with reduced expression of E-cadherin protein in SBAC (P < 0.01) ;④The hypermethylation of E-cadherin gene and the expression of E-cadherin protein were significantly correlated with the invasive depth,the differentiation and lymph node metastasis (P <0.05),but no correlation with other clinico-pathologic parameters such as age, sex ,tumors′size,location(P >0.05).Conclusions:①The hypermethylation of E-cadherin gene detected in cancerous tissues was significantly higher than that in adjacent normal tissues,which indicated hypermethylation of this gene maybe an important biomarker in SBAC tumorigensis.②Hypermethylation of E-cadherin gene and E-cadherin protein expression were associated with the lymphnode metastasis, which could be used as a putative prognostic indicator for SBAC malignancy.