VHL synthetic lethality screens uncover CBF-β as a negative regulator of STING

James A C Bertlin1, Tekle Pauzaite1, Qian Liang2

  • 1Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Jeffrey Cheah Biomedical Centre, Department of Medicine, University of Cambridge, Cambridge, CB2 0AW, UK.

Insights

Loss of Core Binding Factor β (CBF-β) selectively kills clear cell renal cell carcinoma (ccRCC) cells lacking the von Hippel-Lindau (VHL) gene. This finding reveals a new therapeutic strategy for VHL-deficient kidney cancers.

Area of Science:

  • Oncology
  • Genetics
  • Molecular Biology

Background:

  • Clear cell renal cell carcinoma (ccRCC) is the most common kidney cancer.
  • ccRCC is characterized by the inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene.
  • Identifying synthetic lethal interactions with VHL is crucial for developing targeted therapies.

Purpose of the Study:

  • To identify genes that are synthetically lethal with VHL loss in ccRCC.
  • To investigate the role of Core Binding Factor β (CBF-β) in VHL-deficient ccRCC.
  • To elucidate the molecular mechanisms underlying CBF-β's synthetic lethality with VHL loss.

Main Methods:

  • Genome-wide CRISPR/Cas9 screening was employed to identify VHL synthetic lethal interactors.
  • Cell viability assays were performed on VHL-null ccRCC cell lines with and without CBF-β.
  • In vivo tumor growth studies were conducted.
  • Mechanistic studies involved analyzing gene expression and signaling pathways, including type I interferon signaling and the STING locus.

Main Results:

  • Loss of CBF-β leads to cell death in VHL-null ccRCC cells.
  • CBF-β loss impairs tumor establishment and growth in vivo.
  • The synthetic lethality is independent of hypoxia-inducible factors (HIFs) but involves RUNX transcription factors.
  • CBF-β loss upregulates type I interferon signaling by directly inhibiting the STING locus.

Conclusions:

  • CBF-β is a synthetic lethal interactor of VHL in ccRCC.
  • Targeting CBF-β selectively induces tumor cell lethality and activates type I interferon signaling in kidney cancer.
  • This presents a potential novel therapeutic strategy for VHL-deficient ccRCC.