BACKGROUND: CpG island hypermethylation of tumor suppressor genes is highly involved in gastric carcinogenesis, and enhanced cell proliferation could accelerate this process. Cyclin D1 regulates cell cycle function and may play a role in methylation-related carcinogenesis. AIMS: We investigated the association between Cyclin D1 gene G870A polymorphism and the methylation status of tumor suppressor genes in gastric cancer. METHODS: Polymorphisms at G870A in the Cyclin D1 gene were genotyped, and methylation status of the p14, p16, DAP-kinase, and CDH1 genes were determined by methylation-specific-polymerase chain reaction in 139 gastric cancer tissues. CIHM high was defined as three or more methylated CpG islands. RESULTS: Although no association was found between methylation status and different stages and Lauren's subtypes, patients with CIHM of DAP-kinase showed significantly worse survival than those without (p = 0.017). In addition, the number of methylated sites was also associated with survival curves (p = 0.0397). The 870G carrier a significantly lower prevalence of CIHM high compared to the AA genotype in advanced-stage gastric cancer (adjusted OR = 0.32, p = 0.047). A weak correlation between the same genotypes and CIHM of p14 were found in the same subtype (adjusted OR = 0.32, p = 0.052). The mean methylation number was significantly lower in G carriers than in AA genotypes in advanced-stage gastric cancer (p = 0.017). CONCLUSIONS: Genetic polymorphism of CCND1 is associated with CIHM status in gastric cancer, especially in the advanced stage, but is independent of clinico-pathological features.
BACKGROUND: CpG island hypermethylation of tumor suppressor genes is highly involved in gastric carcinogenesis, and enhanced cell proliferation could accelerate this process. Cyclin D1 regulates cell cycle function and may play a role in methylation-related carcinogenesis. AIMS: We investigated the association between Cyclin D1 gene G870A polymorphism and the methylation status of tumor suppressor genes in gastric cancer. METHODS: Polymorphisms at G870A in the Cyclin D1 gene were genotyped, and methylation status of the p14, p16, DAP-kinase, and CDH1 genes were determined by methylation-specific-polymerase chain reaction in 139 gastric cancer tissues. CIHM high was defined as three or more methylated CpG islands. RESULTS: Although no association was found between methylation status and different stages and Lauren's subtypes, patients with CIHM of DAP-kinase showed significantly worse survival than those without (p = 0.017). In addition, the number of methylated sites was also associated with survival curves (p = 0.0397). The 870G carrier a significantly lower prevalence of CIHM high compared to the AA genotype in advanced-stage gastric cancer (adjusted OR = 0.32, p = 0.047). A weak correlation between the same genotypes and CIHM of p14 were found in the same subtype (adjusted OR = 0.32, p = 0.052). The mean methylation number was significantly lower in G carriers than in AA genotypes in advanced-stage gastric cancer (p = 0.017). CONCLUSIONS: Genetic polymorphism of CCND1 is associated with CIHM status in gastric cancer, especially in the advanced stage, but is independent of clinico-pathological features.
Authors: A I Robles; F Larcher; R B Whalin; R Murillas; E Richie; I B Gimenez-Conti; J L Jorcano; C J Conti Journal: Proc Natl Acad Sci U S A Date: 1996-07-23 Impact factor: 11.205
Authors: Y Hirata; S Maeda; Y Mitsuno; M Akanuma; Y Yamaji; K Ogura; H Yoshida; Y Shiratori; M Omata Journal: Infect Immun Date: 2001-06 Impact factor: 3.441