Dataset Information

Epigenetic Drivers in Pediatric Medulloblastoma.

ABSTRACT: Epigenetics is the process by which gene expression is regulated by events other than alterations of the genome. This includes DNA methylation, histone modifications, chromatin remodeling, microRNAs, and long non-coding RNAs. Methylation of DNA, chromatin remodeling, and histone modifications regulate the chromatin and access of transcription factors to DNA and in turn gene transcription. Alteration of chromatin is now recognized to be deregulated in many cancers. Medulloblastoma is an embryonal tumor of the cerebellum and the most common malignant brain tumor in children, that occurs only rarely in adults. Medulloblastoma is characterized by four major molecularly and histopathologically distinct groups, wingless (WNT), sonic hedgehog (SHH), group 3 (G3), and group 4 (G4), that, except for WNT, are each now subdivided in several subgroups. Gene expression array, next-generation sequencing, and methylation profiling of several hundred primary tumors by several consortia and independent groups revealed that medulloblastomas harbor a paucity of mutations most of which occur in epigenetic regulators, genetic alterations in oncogenes and tumor suppressors, in addition to copy number alterations and chromosome gains and losses. Remarkably, some tumors have no reported mutations, suggesting that some genes required for oncogenesis might be regulated by epigenetic mechanisms which are still to be uncovered and validated. This review will highlight several epigenetic regulators focusing mainly on histone modifiers identified in medulloblastoma.

SUBMITTER: Roussel MF

PROVIDER: S-EPMC5807456 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Epigenetic Drivers in Pediatric Medulloblastoma.

Roussel Martine F MF Stripay Jennifer L JL

Cerebellum (London, England) 20180201 1

Epigenetics is the process by which gene expression is regulated by events other than alterations of the genome. This includes DNA methylation, histone modifications, chromatin remodeling, microRNAs, and long non-coding RNAs. Methylation of DNA, chromatin remodeling, and histone modifications regulate the chromatin and access of transcription factors to DNA and in turn gene transcription. Alteration of chromatin is now recognized to be deregulated in many cancers. Medulloblastoma is an embryonal ...[more]

PMID: 29178021

Similar Datasets

Project description:Medulloblastoma (MB) is one of the most common malignant pediatric brain tumor. The aim of our study was to understand which mechanisms are involved in aberrant activation of Wnt pathway and its association with MB tumor development. We studied the expression profiles of 19 MBs tumors using a genome-wide approach, furthermore we have included the data obtained from four independent public Datasets of gene expression (see README file below) to increase the statistical power of the study. The expression profiles identified the Wnt inhibitor gene, DKK3, significant down-regulated. DKK3 down-regulation was confirmed by qPCR in 80% of samples (27/33 MB tumors and in 3/5 MB human cell lines). Since DKK3 was found methylated in several cancers we also investigated the status of methylated CpG sites within the three promoters by a combination of two approaches: the MSP and pyrosequencing. MSP showed no methylation in all promoters while the pyrosequencing, a quantitative technique, indicated a very low level of methylation. To verify the epigenetic involvement on DKK3 silencing, we also studied the effect of Trichostatin A (TSA) in 4 MB cell lines (DAOY; D283; D425; D458). After TSA treatment we observed a significant DKK3 mRNA expression increase in 3/4 cell lines compared to the no treated cells. DAOY cells, that have a normal DKK3 expression value, did not change significantly the DKK3 expression after TSA treatment. To further validate the role of histone tail modifications as an epigenetic silencing mechanism for DKK3 in MB, we performed Chromatin Immunoprecipitation (ChIP) experiment using antibodies against acetylated histones. According to our earlier results, TSA treatment increased the signal of the histone modification meH3K4 which is related to a transcriptionally active gene respect to the untreated controls. Finally, we evaluated the DKK3 protein in three MB cell lines (DAOY; D283; D425) after 24h of TSA treatment, by immunofluorescence. We analysed 19 Medulloblastoma tumor from pediatric patients, a commercial pool (Clontech) of 24 normal cerebellum from female and male Caucasians (ages: 16-70 years; cause of death: sudden death) and a pool of 10 normal cerebellum from children (6 Caucasians and 4 African Americans; ages: 0-16 years; cause of death: sudden death) using 44K whole genome oligonucleotids microarray

Dataset Information

Epigenetic Drivers in Pediatric Medulloblastoma.

Publications

Epigenetic Drivers in Pediatric Medulloblastoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets