The N550K/H mutations in FGFR2 confer differential resistance to PD173074, dovitinib, and ponatinib ATP-competitive inhibitors

Neoplasia. 2013 Aug;15(8):975-88. doi: 10.1593/neo.121106.


We sought to identify fibroblast growth factor receptor 2 (FGFR2) kinase domain mutations that confer resistance to the pan-FGFR inhibitor, dovitinib, and explore the mechanism of action of the drug-resistant mutations. We cultured BaF3 cells overexpressing FGFR2 in high concentrations of dovitinib and identified 14 dovitinib-resistant mutations, including the N550K mutation observed in 25% of FGFR2(mutant) endometrial cancers (ECs). Structural and biochemical in vitro kinase analyses, together with BaF3 proliferation assays, showed that the resistance mutations elevate the intrinsic kinase activity of FGFR2. BaF3 lines were used to assess the ability of each mutation to confer cross-resistance to PD173074 and ponatinib. Unlike PD173074, ponatinib effectively inhibited all the dovitinib-resistant FGFR2 mutants except the V565I gatekeeper mutation, suggesting ponatinib but not dovitinib targets the active conformation of FGFR2 kinase. EC cell lines expressing wild-type FGFR2 were relatively resistant to all inhibitors, whereas EC cell lines expressing mutated FGFR2 showed differential sensitivity. Within the FGFR2(mutant) cell lines, three of seven showed marked resistance to PD173074 and relative resistance to dovitinib and ponatinib. This suggests that alternative mechanisms distinct from kinase domain mutations are responsible for intrinsic resistance in these three EC lines. Finally, overexpression of FGFR2(N550K) in JHUEM-2 cells (FGFR2(C383R)) conferred resistance (about five-fold) to PD173074, providing independent data that FGFR2(N550K) can be associated with drug resistance. Biochemical in vitro kinase analyses also show that ponatinib is more effective than dovitinib at inhibiting FGFR2(N550K). We propose that tumors harboring mutationally activated FGFRs should be treated with FGFR inhibitors that specifically bind the active kinase.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Benzimidazoles / pharmacology*
  • Binding Sites / genetics
  • Biocatalysis / drug effects
  • Cell Line
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drug Resistance, Neoplasm / drug effects
  • Drug Resistance, Neoplasm / genetics
  • Electrophoresis, Polyacrylamide Gel
  • Endometrial Neoplasms / genetics
  • Endometrial Neoplasms / metabolism
  • Endometrial Neoplasms / pathology
  • Female
  • Humans
  • Imidazoles / pharmacology*
  • Inhibitory Concentration 50
  • Models, Molecular
  • Mutation*
  • Phosphorylation / drug effects
  • Protein Kinase Inhibitors / pharmacology
  • Protein Structure, Tertiary
  • Pyridazines / pharmacology*
  • Pyrimidines / pharmacology*
  • Quinolones / pharmacology*
  • Receptor, Fibroblast Growth Factor, Type 2 / chemistry
  • Receptor, Fibroblast Growth Factor, Type 2 / genetics*
  • Receptor, Fibroblast Growth Factor, Type 2 / metabolism


  • 4-amino-5-fluoro-3-(5-(4-methylpiperazin-1-yl)-1H-benzimidazol-2-yl)quinolin-2(1H)-one
  • Benzimidazoles
  • Imidazoles
  • PD 173074
  • Protein Kinase Inhibitors
  • Pyridazines
  • Pyrimidines
  • Quinolones
  • ponatinib
  • Adenosine Triphosphate
  • Receptor, Fibroblast Growth Factor, Type 2