Distinct promoter hypermethylation of p16INK4a, CDH1, and RAR-beta in intestinal, diffuse-adherent, and diffuse-scattered type gastric carcinomas.
Hypermethylation of CpG islands in gene promoters is associated with silencing of various tumour suppressor genes. Recent studies of colorectal and gastric carcinomas have defined a CpG island methylator phenotype (CIMP), which involves the targeting of multiple genes by promoter hypermethylation. In this study, methylation-specific polymerase chain reaction (PCR) was performed to study methylation of CpG islands in the promoters of the p16(INK4a), cadherin 1 (CDH1), and retinoic acid receptor-beta (RAR-beta) genes in 45 gastric carcinomas and to investigate whether CDH1 and RAR-beta promoter hypermethylation is associated with CIMP-positive gastric carcinoma. CpG island hypermethylation of the p16(INK4a), CDH1, and RAR-beta promoters was detected in 12 (27%), 26 (58%), and 24 (53%) of the 45 gastric carcinomas, respectively. Hypermethylation of the p16(INK4a) promoter was more common in intestinal type than in diffuse type gastric carcinomas (p = 0.0023; Fisher's exact test) and was inversely associated with p53 mutations (p = 0.0225; Fisher's exact test). However, CDH1 and RAR-beta promoter hypermethylation was observed more frequently in diffuse-scattered type gastric carcinoma than in other types (intestinal and diffuse-adherent types) (p = 0.0175 and p = 0.0335, respectively; Fisher's exact test) and was not associated with p53 mutation status. Moreover, hypermethylation of the CDH1 and RAR-beta promoters occurred concordantly (p < 0.0001; Fisher's exact test). These results suggest that at least two types of promoter methylation status are involved in the development of the intestinal (p16(INK4a) promoter hypermethylation) and diffuse-scattered types (CDH1 and RAR-beta promoter hypermethylation) of gastric carcinoma.
Oue
Naohide
N
Department of Molecular Pathology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Motoshita
Junichi
J
Yokozaki
Hiroshi
H
Hayashi
Ken
K
Tahara
Eiichi
E
Taniyama
Kiyomi
K
Matsusaki
Keisuke
K
Yasui
Wataru
W
D015703:Antigens, CD; D015820:Cadherins; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics; D019942:Genes, p16; D016158:Genes, p53; D006801:Humans; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D018168:Receptors, Retinoic Acid / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta