Multi-omics analysis of intertumoral heterogeneity within medulloblastoma uncharted-pathway subtypes

Brain Tumor Pathol. 2021 Jul;38(3):234-242. doi: 10.1007/s10014-021-00400-7. Epub 2021 Jun 28.

Abstract

Medulloblastoma is a common pediatric malignant brain tumor. There were four consensus molecular subgroups (WNT, SHH, Group3 and Group4). Group 3 and Group 4 tumors exhibited a great degree of transcriptional overlap, and were neither derived from exact pathway aberration. We investigated transcriptional and chromatin accessibility of medulloblastoma by multi-omics single-cell analysis. Our work identified inter- and intra-tumoral heterogeneity within the Group 3, Group 4 and Group 3/4 intermediate subgroups. Unsupervised cluster of each tumor identified 9 cell clusters with transcriptional profiles and 6 cell clusters with chromatin accessibility profiles. OTX2 had the highest activity and expression level across the clusters in a special cluster based on open chromatin single-cell profilings. We identified multiple genes as a significant targeted gene within the OTX2 target genes, which made sense in prognosis. We analyzed the copy-number-variations which presented with expected subgroup distribution from transcriptional and chromatin accessibility profiles. Collectively, these data provide novel insights into Group 3 and Group 4 medulloblastoma and provide a potential therapeutic target.

Keywords: Medulloblastoma; Multi-omics analysis; Single-cell sequencing.

MeSH terms

  • Brain Neoplasms / classification
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / therapy
  • Child
  • Chromatin / genetics
  • DNA Copy Number Variations / genetics
  • Female
  • Gene Expression Profiling
  • Humans
  • Male
  • Medulloblastoma / classification
  • Medulloblastoma / genetics*
  • Medulloblastoma / pathology
  • Medulloblastoma / therapy
  • Molecular Targeted Therapy
  • Otx Transcription Factors / genetics
  • Prognosis
  • Transcription, Genetic

Substances

  • Chromatin
  • OTX2 protein, human
  • Otx Transcription Factors