Spatial progression and molecular heterogeneity of IDH-mutant glioblastoma determined by DNA methylation-based mapping

James F. Lyon, Varshini Vasudevaraja, Kanish Mirchia, Jamie M. Walker, Robert J. Corona, Lawrence S. Chin, Ivy Tran, Matija Snuderl, Timothy E. Richardson, Mariano S. Viapiano

Research output: Contribution to journalArticlepeer-review

Abstract

Glioblastoma (GBM) is the most common malignant primary central nervous system (CNS) neoplasm in adults, and has an almost universally poor prognosis. Recently, an emphasis on genetic and epigenetic profiling has revealed a number of molecular features useful in the diagnostic and prognostic classification of GBM, advancing our understanding of the underlying features that make these tumors so aggressive and providing the rationale for the creation of better targeted therapeutics. One such method, DNA methylation profiling, has recently emerged as an important technique for the classification of CNS tumors, with diagnostic accuracy in some cases surpassing traditional methods. However, how DNA methylation profiles change with the course of the disease remains less understood. Here, we present a case of a 30-year-old male with primary IDH-mutant GBM with widespread recurrence and death two years later. Using unsupervised hierarchical clustering of methylation probes, we created a phylogenetic map to trace the tumor path as it spread from the initial biopsy site throughout the right hemisphere, across the corpus callosum to the contralateral hemisphere, and into the brainstem. We identified molecular divergence between the right and left hemisphere GBM samples marked by distinct copy number profile alterations, alterations in specific methylation sites, and regional loss of MGMT promoter methylation, providing a potential mechanism for treatment resistance in this case. In summary, this case both highlights the molecular diversity in GBM, and illustrates a novel use for methylation profiling in establishing a phylogenetic profile to allow for spatial mapping of tumor progression.

Original languageEnglish (US)
Pages (from-to)120
Number of pages1
JournalActa Neuropathologica Communications
Volume9
Issue number1
DOIs
StatePublished - Jun 30 2021

Keywords

  • Astrocytoma
  • Copy number profiling
  • DNA methylation profiling
  • Glioblastoma
  • IDH-mutation
  • MGMT methylation

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Clinical Neurology
  • Cellular and Molecular Neuroscience

Fingerprint

Dive into the research topics of 'Spatial progression and molecular heterogeneity of IDH-mutant glioblastoma determined by DNA methylation-based mapping'. Together they form a unique fingerprint.

Cite this