title: Epigenetic dysregulation: a novel pathway of oncogenesis in pediatric brain tumors.
abstract: A remarkably large number of "epigenetic regulators" have been recently identified to be altered in cancers and a rapidly expanding body of literature points to "epigenetic addiction" (an aberrant epigenetic state to which a tumor is addicted) as a new previously unsuspected mechanism of oncogenesis. Although mutations are also found in canonical signaling pathway genes, we and others identified chromatin-associated proteins to be more commonly altered by somatic alterations than any other class of oncoprotein in several subgroups of childhood high-grade brain tumors. Furthermore, as these childhood malignancies carry fewer non-synonymous somatic mutations per case in contrast to most adult cancers, these mutations are likely drivers in these tumors. Herein, we will use as examples of this novel hallmark of oncogenesis high-grade astrocytomas, including glioblastoma, and a subgroup of embryonal tumors, embryonal tumor with multilayered rosettes (ETMR) to describe the novel molecular defects uncovered in these deadly tumors. We will further discuss evidence for their profound effects on the epigenome. The relative genetic simplicity of these tumors promises general insights into how mutations in the chromatin machinery modify downstream epigenetic signatures to drive transformation, and how to target this plastic genetic/epigenetic interface.
authors: Division of Experimental Medicine, Montreal Children's Hospital, McGill University and McGill University Health Centre, 4060 Ste Catherine West, PT239, Montreal, QC, H3Z 2Z3, Canada.
authors: Adam M
authors: AM
authors: Fontebasso
authors: Tenzin
authors: T
authors: Gayden
authors: Hamid
authors: H
authors: Nikbakht
authors: Michael
authors: M
authors: Neirinck
authors: Simon
authors: S
authors: Papillon-Cavanagh
authors: Jacek
authors: J
authors: Majewski
authors: Nada
authors: N
authors: Jabado
mesh_terms: D001932:Brain Neoplasms / Q000235:genetics*; D063646:Carcinogenesis / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000235:genetics*; D006801:Humans; D010372:Pediatrics