Inhibition of RAF Isoforms and Active Dimers by LY3009120 Leads to Anti-tumor Activities in RAS or BRAF Mutant Cancers

Cancer Cell. 2015 Sep 14;28(3):384-98. doi: 10.1016/j.ccell.2015.08.002. Epub 2015 Sep 3.

Abstract

LY3009120 is a pan-RAF and RAF dimer inhibitor that inhibits all RAF isoforms and occupies both protomers in RAF dimers. Biochemical and cellular analyses revealed that LY3009120 inhibits ARAF, BRAF, and CRAF isoforms with similar affinity, while vemurafenib or dabrafenib have little or modest CRAF activity compared to their BRAF activities. LY3009120 induces BRAF-CRAF dimerization but inhibits the phosphorylation of downstream MEK and ERK, suggesting that it effectively inhibits the kinase activity of BRAF-CRAF heterodimers. Further analyses demonstrated that LY3009120 also inhibits various forms of RAF dimers including BRAF or CRAF homodimers. Due to these unique properties, LY3009120 demonstrates minimal paradoxical activation, inhibits MEK1/2 phosphorylation, and exhibits anti-tumor activities across multiple models carrying KRAS, NRAS, or BRAF mutation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Dimerization
  • Humans
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / genetics
  • Mitogen-Activated Protein Kinases / genetics
  • Mutation / drug effects
  • Mutation / genetics
  • Neoplasms / drug therapy*
  • Neoplasms / genetics
  • Phenylurea Compounds / pharmacology*
  • Phosphorylation / drug effects
  • Phosphorylation / genetics
  • Protein Isoforms / antagonists & inhibitors*
  • Protein Isoforms / genetics
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins B-raf / antagonists & inhibitors*
  • Proto-Oncogene Proteins B-raf / genetics*
  • Proto-Oncogene Proteins c-raf / genetics
  • Pyrimidines / pharmacology*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • ras Proteins / genetics*

Substances

  • Antineoplastic Agents
  • LY3009120
  • Phenylurea Compounds
  • Protein Isoforms
  • Protein Kinase Inhibitors
  • Pyrimidines
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • Proto-Oncogene Proteins c-raf
  • Mitogen-Activated Protein Kinases
  • ras Proteins