Identification of long-range epigenetic silencing on chromosome 15q25 and its clinical implication in gastric cancer.
Am J Pathol
; 185(3): 666-78, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25576785
ABSTRACT
Recent genome-wide epigenomic and transcription profiling studies have demonstrated that epigenetic silencing can encompass multiple neighboring genes, termed as long-range epigenetic silencing (LRES). Herein, we identified a novel LRES region by comparing gene expression of human colon cancer HCT116 cells with their DNA methyltransferase 1 and DNA methyltransferase 3B double-knockout derivative double-knockout cells. Ten consecutive genes spanning 3 Mb of chromosome 15q25 were coordinately silenced, with eight genes showing promoter CpG island hypermethylation and enrichment of repressive histone marks, which were evaluated by bisulfite sequencing analysis and chromatin immunoprecipitation assay. Comparison of primary gastric tumor specimens with normal tissue confirmed that the long-range silencing of this region was tumor specific. Methylation of genes within the LRES region was evaluated in 190 gastric tumor tissues using the MethyLight assay, and their association with clinicopathological features, such as older age, high-grade differentiation, and diffuse or mixed-type histology, was determined. LRES-positive gastric cancer patients (six or more methylated genes) showed lower recurrence and better survival. Our findings emphasize the differential dynamics of DNA methylation and histone modification, indicating the importance of studying the relationship of each epigenetic modification in the context of chromatin domains. Patients with LRES showed lower recurrence and better prognosis, indicating that stratifying patients according to underlying molecular features, such as LRES regions, may better predict recurrence and survival.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Gástricas
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Cromossomos Humanos Par 15
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Inativação Gênica
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Epigênese Genética
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Recidiva Local de Neoplasia
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
Limite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article