DNA methylation analysis of paediatric low-grade astrocytomas identifies a tumour-specific hypomethylation signature in pilocytic astrocytomas.
Acta Neuropathol Commun
; 4(1): 54, 2016 05 27.
Article
em En
| MEDLINE
| ID: mdl-27229157
ABSTRACT
Low-grade gliomas (LGGs) account for about a third of all brain tumours in children. We conducted a detailed study of DNA methylation and gene expression to improve our understanding of the biology of pilocytic and diffuse astrocytomas. Pilocytic astrocytomas were found to have a distinctive signature at 315 CpG sites, of which 312 were hypomethylated and 3 were hypermethylated. Genomic analysis revealed that 182 of these sites are within annotated enhancers. The signature was not present in diffuse astrocytomas, or in published profiles of other brain tumours and normal brain tissue. The AP-1 transcription factor was predicted to bind within 200 bp of a subset of the 315 differentially methylated CpG sites; the AP-1 factors, FOS and FOSL1 were found to be up-regulated in pilocytic astrocytomas. We also analysed splice variants of the AP-1 target gene, CCND1, which encodes cell cycle regulator cyclin D1. CCND1a was found to be highly expressed in both pilocytic and diffuse astrocytomas, but diffuse astrocytomas have far higher expression of the oncogenic variant, CCND1b. These findings highlight novel genetic and epigenetic differences between pilocytic and diffuse astrocytoma, in addition to well-described alterations involving BRAF, MYB and FGFR1.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Astrocitoma
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Neoplasias Encefálicas
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Metilação de DNA
Tipo de estudo:
Prognostic_studies
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
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Middle aged
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Newborn
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article