Dissecting Hes-centred transcriptional networks in neural stem cell maintenance and tumorigenesis in Drosophila

Development. 2020 Nov 23;147(22):dev191544. doi: 10.1242/dev.191544.

Abstract

Neural stem cells divide during embryogenesis and juvenile life to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that, in every asymmetric cell division, progenitors send a Delta-Notch signal to their sibling stem cells. Here, we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in the Drosophila larval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. We describe the impact of two of these 'anti-stemness' factors, Zfh1 and Gcm, on Notch/Hes-triggered tumorigenesis.

Keywords: Cancer models in Drosophila; Drosophila; Hes; Neural stem cells; Notch signalling; Transcription factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Carcinogenesis / genetics
  • Carcinogenesis / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster
  • Gene Regulatory Networks*
  • Neural Stem Cells / metabolism*
  • Receptors, Notch / genetics
  • Receptors, Notch / metabolism
  • Signal Transduction*
  • Transcription, Genetic*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • DNA-Binding Proteins
  • Drosophila Proteins
  • N protein, Drosophila
  • Receptors, Notch
  • Dpn protein, Drosophila