Combinatorial CRISPR-Cas9 Metabolic Screens Reveal Critical Redox Control Points Dependent on the KEAP1-NRF2 Regulatory Axis

Mol Cell. 2018 Feb 15;69(4):699-708.e7. doi: 10.1016/j.molcel.2018.01.017.

Abstract

The metabolic pathways fueling tumor growth have been well characterized, but the specific impact of transforming events on network topology and enzyme essentiality remains poorly understood. To this end, we performed combinatorial CRISPR-Cas9 screens on a set of 51 carbohydrate metabolism genes that represent glycolysis and the pentose phosphate pathway (PPP). This high-throughput methodology enabled systems-level interrogation of metabolic gene dispensability, interactions, and compensation across multiple cell types. The metabolic impact of specific combinatorial knockouts was validated using 13C and 2H isotope tracing, and these assays together revealed key nodes controlling redox homeostasis along the KEAP-NRF2 signaling axis. Specifically, targeting KEAP1 in combination with oxidative PPP genes mitigated the deleterious effects of these knockouts on growth rates. These results demonstrate how our integrated framework, combining genetic, transcriptomic, and flux measurements, can improve elucidation of metabolic network alterations and guide precision targeting of metabolic vulnerabilities based on tumor genetics.

Keywords: KEAP1; NADPH; NRF2; combinatorial CRISPR screening; genetic interactions; glycolysis; metabolic enzyme compensation; metabolic enzyme essentiality; metabolic flux analysis; redox metabolism.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • CRISPR-Cas Systems*
  • Glycolysis
  • HeLa Cells
  • Homeostasis
  • Humans
  • Kelch-Like ECH-Associated Protein 1 / antagonists & inhibitors
  • Kelch-Like ECH-Associated Protein 1 / genetics
  • Kelch-Like ECH-Associated Protein 1 / metabolism*
  • Metabolic Networks and Pathways*
  • NF-E2-Related Factor 2 / antagonists & inhibitors
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidation-Reduction
  • Pentose Phosphate Pathway
  • Signal Transduction
  • Transcriptome*

Substances

  • KEAP1 protein, human
  • Kelch-Like ECH-Associated Protein 1
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human