Drugging the catalytically inactive state of RET kinase in RET-rearranged tumors

Sci Transl Med. 2017 Jun 14;9(394):eaah6144. doi: 10.1126/scitranslmed.aah6144.

Abstract

Oncogenic fusion events have been identified in a broad range of tumors. Among them, RET rearrangements represent distinct and potentially druggable targets that are recurrently found in lung adenocarcinomas. We provide further evidence that current anti-RET drugs may not be potent enough to induce durable responses in such tumors. We report that potent inhibitors, such as AD80 or ponatinib, that stably bind in the DFG-out conformation of RET may overcome these limitations and selectively kill RET-rearranged tumors. Using chemical genomics in conjunction with phosphoproteomic analyses in RET-rearranged cells, we identify the CCDC6-RETI788N mutation and drug-induced mitogen-activated protein kinase pathway reactivation as possible mechanisms by which tumors may escape the activity of RET inhibitors. Our data provide mechanistic insight into the druggability of RET kinase fusions that may be of help for the development of effective therapies targeting such tumors.

MeSH terms

  • Adenocarcinoma / metabolism*
  • Adenocarcinoma of Lung
  • Animals
  • Cell Line, Tumor
  • Cytoskeletal Proteins / genetics
  • Drug Resistance, Neoplasm / genetics
  • Gene Rearrangement / drug effects
  • Gene Rearrangement / genetics*
  • Heterocyclic Compounds, 4 or More Rings / pharmacology
  • Humans
  • Imidazoles / pharmacology
  • Lung Neoplasms / metabolism*
  • Mice
  • Mutation
  • NIH 3T3 Cells
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins c-ret / genetics*
  • Pyridazines / pharmacology

Substances

  • AD80 compound
  • CCDC6 protein, human
  • Cytoskeletal Proteins
  • Heterocyclic Compounds, 4 or More Rings
  • Imidazoles
  • Protein Kinase Inhibitors
  • Pyridazines
  • ponatinib
  • Proto-Oncogene Proteins c-ret