Format

Send to

Choose Destination
Cancer Discov. 2016 Mar;6(3):316-29. doi: 10.1158/2159-8290.CD-15-1105. Epub 2016 Jan 6.

Selective Inhibition of Oncogenic KRAS Output with Small Molecules Targeting the Inactive State.

Author information

1
Wellspring Biosciences, La Jolla, California.
2
Wellspring Biosciences, La Jolla, California. yi@kuraoncology.com.

Abstract

KRAS gain-of-function mutations occur in approximately 30% of all human cancers. Despite more than 30 years of KRAS-focused research and development efforts, no targeted therapy has been discovered for cancers with KRAS mutations. Here, we describe ARS-853, a selective, covalent inhibitor of KRAS(G12C) that inhibits mutant KRAS-driven signaling by binding to the GDP-bound oncoprotein and preventing activation. Based on the rates of engagement and inhibition observed for ARS-853, along with a mutant-specific mass spectrometry-based assay for assessing KRAS activation status, we show that the nucleotide state of KRAS(G12C) is in a state of dynamic flux that can be modulated by upstream signaling factors. These studies provide convincing evidence that the KRAS(G12C) mutation generates a "hyperexcitable" rather than a "statically active" state and that targeting the inactive, GDP-bound form is a promising approach for generating novel anti-RAS therapeutics.

SIGNIFICANCE:

A cell-active, mutant-specific, covalent inhibitor of KRAS(G12C) is described that targets the GDP-bound, inactive state and prevents subsequent activation. Using this novel compound, we demonstrate that KRAS(G12C) oncoprotein rapidly cycles bound nucleotide and responds to upstream signaling inputs to maintain a highly active state.

PMID:
26739882
DOI:
10.1158/2159-8290.CD-15-1105
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center