Modeling epigenetic lesions that cause gliomas

Gilbert J Rahme1, Nauman M Javed1, Kaitlyn L Puorro2

  • 1Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02215, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.

Cell
|July 26, 2023
PubMed

Insights

Disrupting a CTCF insulator near PDGFRA in mouse cells increases proliferation. Combined with Cdkn2a tumor suppressor loss, this drives glioma formation, offering insights into cancer drivers.

Area of Science:

  • Cancer biology
  • Epigenetics
  • Genomics

Background:

  • Epigenetic alterations disrupting regulatory elements are potential cancer drivers.
  • Experimental models are needed to validate the tumorigenic impact of these lesions.
  • Isocitrate dehydrogenase-mutant gliomas show DNA hypermethylation, suggesting epigenetic drivers.

Purpose of the Study:

  • To model epigenetic aberrations in isocitrate dehydrogenase-mutant gliomas.
  • To investigate the role of a CTCF insulator disruption near PDGFRA in gliomagenesis.
  • To understand the cooperation between insulator disruption and tumor suppressor gene silencing.

Main Methods:

  • Modeling of CTCF insulator disruption in mouse oligodendrocyte progenitor cells (OPCs).
  • Analysis of PDGFRA oncogene activation by an OPC-specific enhancer.
  • Assessment of Cdkn2a tumor suppressor silencing and its cooperation with insulator loss.
  • In vivo gliomagenesis studies.

Main Results:

  • Disruption of the CTCF insulator in mouse OPCs led to PDGFRA activation and increased proliferation.
  • Methylation-dependent silencing of Cdkn2a cooperated with insulator loss.
  • Coordinate inactivation of the PDGFRA insulator and Cdkn2a drove gliomagenesis in vivo.
  • Human-specific CpG richness in the insulator complicates mouse modeling but suggests a role in human glioma risk.

Conclusions:

  • Recurrent epigenetic lesions can drive oligodendrocyte progenitor cell proliferation in vitro.
  • Coordinated epigenetic alterations, including insulator disruption and tumor suppressor silencing, drive gliomagenesis in vivo.
  • The study highlights the potential of epigenetic lesions as cancer drivers and the challenges in modeling human-specific epigenetic features.

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