1. Academic Validation
  2. KRASG12C inhibition produces a driver-limited state revealing collateral dependencies

KRASG12C inhibition produces a driver-limited state revealing collateral dependencies

  • Sci Signal. 2019 May 28;12(583):eaaw9450. doi: 10.1126/scisignal.aaw9450.
Kevin Lou 1 Veronica Steri 2 3 Alex Y Ge 2 4 Y Christina Hwang 2 5 Christopher H Yogodzinski 2 4 Arielle R Shkedi 6 Alex L M Choi 2 5 Dominique C Mitchell 2 5 Danielle L Swaney 1 7 Byron Hann 2 3 John D Gordan 2 5 Kevan M Shokat 8 9 Luke A Gilbert 10 4 11
Affiliations

Affiliations

  • 1 Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA.
  • 2 Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA.
  • 3 Preclinical Therapeutics Core, University of California, San Francisco, San Francisco, CA 94158, USA.
  • 4 Department of Urology, University of California, San Francisco, San Francisco, CA 94158, USA.
  • 5 Department of Medicine and Division of Hematology/Oncology, University of California, San Francisco, San Francisco, CA 94158, USA.
  • 6 Institute for Neurodegenerative Diseases and Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA.
  • 7 Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA.
  • 8 Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA. luke.gilbert@ucsf.edu kevan.shokat@ucsf.edu.
  • 9 Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, USA.
  • 10 Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA. luke.gilbert@ucsf.edu kevan.shokat@ucsf.edu.
  • 11 Innovative Genomics Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
Abstract

Inhibitors targeting KRASG12C, a mutant form of the guanosine triphosphatase (GTPase) KRAS, are a promising new class of oncogene-specific therapeutics for the treatment of tumors driven by the mutant protein. These inhibitors react with the mutant cysteine residue by binding covalently to the switch-II pocket (S-IIP) that is present only in the inactive guanosine diphosphate (GDP)-bound form of KRASG12C, sparing the wild-type protein. We used a genome-scale CRISPR interference (CRISPRi) functional genomics platform to systematically identify genetic interactions with a KRASG12C inhibitor in cellular models of KRASG12C mutant lung and pancreatic Cancer. Our data revealed genes that were selectively essential in this oncogenic driver-limited cell state, meaning that their loss enhanced cellular susceptibility to direct KRASG12C inhibition. We termed such genes "collateral dependencies" (CDs) and identified two classes of combination therapies targeting these CDs that increased KRASG12C target engagement or blocked residual survival pathways in cells and in vivo. From our findings, we propose a framework for assessing genetic dependencies induced by oncogene inhibition.

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