Relationship Between the Extent of Chromosomal Losses and the Pattern of CpG Methylation in Gastric Carcinomas
Journal of Korean Medical Science
; : 790-805, 2005.
Article
de En
| WPRIM
| ID: wpr-176546
Bibliothèque responsable:
WPRO
ABSTRACT
The extent of unilateral chromosomal losses and the presence of microsatellite instability (MSI) have been classified into high-risk (high- and baseline-level loss) and low-risk (low-level loss and MSI) stem-line genotypes in gastric carcinomas. A unilateral genome-dosage reduction might stimulate compensation mechanism, which maintains the genomic dosage via CpG hypomethylation. A total of 120 tumor sites from 40 gastric carcinomas were examined by chromosomal loss analysis using 40 microsatellite markers on 8 chromosomes and methylation analysis in the 13 CpG (island/non-island) regions near the 10 genes using the bisulfite-modified DNAs. The high-level-loss tumor (four or more losses) showed a tendency toward unmethylation in the Maspin, CAGE, MAGE-A2 and RABGEF1 genes, and the other microsatellite-genotype (three or fewer losses and MSI) toward methylation in the p16, hMLH1, RASSF1A, and Cyclin D2 genes (p<0.05). The non-island CpGs of the p16 and hMLH1 genes were hypomethylated in the high-level-loss and hypermethylated in the non-high-level-loss sites (p<0.05). Consequently, hypomethylation changes were related to a high-level loss, whereas the hypermethylation changes were accompanied by a baseline-level loss, a low-level loss, or a MSI. This indicates that hypomethylation compensates the chromosomal losses in the process of tumor progression.
Mots clés
Texte intégral:
1
Indice:
WPRIM
Sujet Principal:
Polymorphisme génétique
/
Tumeurs de l'estomac
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Analyse de mutations d'ADN
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Dépistage génétique
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Incidence
/
Facteurs de risque
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Aberrations des chromosomes
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Cartographie chromosomique
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Appréciation des risques
/
Répétitions microsatellites
Type d'étude:
Etiology_studies
/
Incidence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limites du sujet:
Humans
Pays comme sujet:
Asia
/
Europa
langue:
En
Texte intégral:
Journal of Korean Medical Science
Année:
2005
Type:
Article