OBJECTIVETo study the promoter hypermethylation of several tumor suppressor genes in gastric carcinoma (GC) tissue and adjacent normal gastric foveolar epithelium (GFE).

METHODSMethylation specific PCR (MSP) was used to examine the promoter methylation of tumor suppressor genes E-cadherin, hMLH1, APC and MGMT in paraffin-embedded gastric cancer tissue and adjacent normal foveolar epithelium in 106 cases.

RESULTSThe positive rate of genes promoter methylation was 44.3% (47/106 cases) and 72.6% (77/106 cases) at one or more genes tested in the normal GFE and GC tissue, respectively. There was a significant difference in the positive rates of gene promoter methylation between normal GFE and GC tissue (P = 0.0001). There was a significant association with Laurén classification, degree of differentiation and pTNM staging in GC (P < 0.05), but no significant association with Ming's classification (P > 0.05).

CONCLUSIONTumor suppressor genes promoter methylation is frequently present in GC and adjacent normal gastric foveolar epithelium, especially in Laurén diffuse type GC, poorly differentiated GC, mucus-secreting (signet ring) cell GC and pTNM stage III and IV GC. Our findings indicate that the gene promoter methylation is a common and early event in GC carcinogensis.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adenomatous Polyposis Coli Protein ; genetics ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Cadherins ; genetics ; metabolism ; DNA Methylation ; DNA Modification Methylases ; genetics ; metabolism ; DNA Repair Enzymes ; genetics ; metabolism ; Epithelium ; metabolism ; pathology ; Female ; Gastric Mucosa ; metabolism ; pathology ; Genes, APC ; Genes, Tumor Suppressor ; Humans ; Male ; Middle Aged ; MutL Protein Homolog 1 ; Neoplasm Staging ; Nuclear Proteins ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Tumor Suppressor Proteins ; genetics ; metabolism ; Young Adult