Chromosomal Losses are Associated with Hypomethylation of the Gene-Control Regions in the Stomach with a Low Number of Active Genes.
10.3346/jkms.2008.23.6.1068
- Author:
Yu Chae JUNG
1
;
Seung Jin HONG
;
Young Ho KIM
;
Sung Ja KIM
;
Seok Jin KANG
;
Sang Wook CHOI
;
Mun Gan RHYU
Author Information
1. Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Korea. rhyumung@catholic.ac.kr
- Publication Type:Original Article ; Comparative Study ; Research Support, Non-U.S. Gov't
- Keywords:
Chromosomal Loss;
Loss of Heterozygosity;
CpG Methylation;
Methylation-Specific PCR;
Tissue Expression Profiles
- MeSH:
Alu Elements/genetics;
*Chromosome Deletion;
CpG Islands/*genetics;
*DNA Methylation;
DNA, Neoplasm/chemistry/isolation & purification;
Gene Expression Profiling;
*Genes, Neoplasm;
Humans;
Long Interspersed Nucleotide Elements/genetics;
Polymerase Chain Reaction;
*Promoter Regions, Genetic;
Stomach Neoplasms/*genetics
- From:Journal of Korean Medical Science
2008;23(6):1068-1089
- CountryRepublic of Korea
- Language:English
-
Abstract:
Transitional-CpG methylation between unmethylated promoters and nearby methylated retroelements plays a role in the establishment of tissue-specific transcription. This study examined whether chromosomal losses reducing the active genes in cancers can change transitional-CpG methylation and the transcription activity in a cancer-type-dependent manner. The transitional-CpG sites at the CpG-island margins of nine genes and the non-island-CpG sites round the transcription start sites of six genes lacking CpG islands were examined by methylation-specific polymerase chain reaction (PCR) analysis. The number of active genes in normal and cancerous tissues of the stomach, colon, breast, and nasopharynx were analyzed using the public data in silico. The CpG-island margins and non-island CpG sites tended to be hypermethylated and hypomethylated in all cancer types, respectively. The CpG-island margins were hypermethylated and a low number of genes were active in the normal stomach compared with other normal tissues. In gastric cancers, the CpG-island margins and non-island-CpG sites were hypomethylated in association with high-level chromosomal losses, and the number of active genes increased. Colon, breast, and nasopharyngeal cancers showed no significant association between the chromosomal losses and methylation changes. These findings suggest that chromosomal losses in gastric cancers are associated with the hypomethylation of the gene-control regions and the increased number of active genes.
