Therapeutic targeting of transcriptional elongation in diffuse intrinsic pontine glioma

Hiroaki Katagi1,2, Nozomu Takata3, Yuki Aoi4

  • 1Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois.

Neuro-Oncology
|January 20, 2021
PubMed
Abstract

Insights

Pharmacological disruption of the super elongation complex (SEC) using KL-1 suppressed diffuse intrinsic pontine glioma (DIPG) cell growth. This SEC inhibition offers a promising therapeutic strategy for H3K27M-mutant DIPG.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Diffuse intrinsic pontine glioma (DIPG) is characterized by transcriptional dysregulation linked to H3K27 mutations.
  • The super elongation complex (SEC) is crucial for transcriptional elongation, releasing RNA polymerase II (Pol II).
  • Targeting SEC to inhibit transcription elongation presents a potential therapeutic avenue for H3K27M-mutant DIPG.

Purpose of the Study:

  • To investigate the therapeutic potential of pharmacologically disrupting the SEC in H3K27M-mutant DIPG.
  • To elucidate the molecular mechanisms underlying SEC inhibition in DIPG.
  • To evaluate a novel therapeutic strategy for DIPG.

Main Methods:

  • Suppressed AF4/FMR2 4 (AFF4), a key SEC component, using short hairpin RNAs (shRNAs).
  • Utilized a peptidomimetic compound KL-1 to disrupt SEC function.
  • Assessed cell viability, colony formation, and apoptosis; performed RNA- and ChIP-sequencing.
  • Evaluated KL-1 efficacy in H3K27M-mutant DIPG patient-derived xenografts (PDXs) in mice.

Main Results:

  • AFF4 depletion significantly inhibited H3K27M-mutant DIPG cell growth.
  • KL-1 treatment enhanced genome-wide Pol II occupancy and suppressed transcription.
  • KL-1 suppressed DIPG cell proliferation and differentiation, increased apoptosis, and prolonged survival in PDX models.

Conclusions:

  • SEC disruption via KL-1 demonstrated therapeutic benefits both in vitro and in vivo.
  • KL-1 shows potential as a therapeutic agent for H3K27M-mutant DIPG.
  • This study supports SEC inhibition as a viable strategy for DIPG treatment.