Transcriptomics and Transposon Mutagenesis Identify Multiple Mechanisms of Resistance to the FGFR Inhibitor AZD4547

Cancer Res. 2018 Oct 1;78(19):5668-5679. doi: 10.1158/0008-5472.CAN-18-0757. Epub 2018 Aug 16.


In human cancers, FGFR signaling is frequently hyperactivated by deregulation of FGF ligands or by activating mutations in the FGFR receptors such as gene amplifications, point mutations, and gene fusions. As such, FGFR inhibitors are considered an attractive therapeutic strategy for patients with mutations in FGFR family members. We previously identified Fgfr2 as a key driver of invasive lobular carcinoma (ILC) in an in vivo insertional mutagenesis screen using the Sleeping Beauty transposon system. Here we explore whether these FGFR-driven ILCs are sensitive to the FGFR inhibitor AZD4547 and use transposon mutagenesis in these tumors to identify potential mechanisms of resistance to therapy. Combined with RNA sequencing-based analyses of AZD4547-resistant tumors, our in vivo approach identified several known and novel potential resistance mechanisms to FGFR inhibition, most of which converged on reactivation of the canonical MAPK-ERK signaling cascade. Observed resistance mechanisms included mutations in the tyrosine kinase domain of FGFR2, overexpression of MET, inactivation of RASA1, and activation of the drug-efflux transporter ABCG2. ABCG2 and RASA1 were identified only from de novo transposon insertions acquired during AZD4547 treatment, demonstrating that insertional mutagenesis in mice is an effective tool for identifying potential mechanisms of resistance to targeted cancer therapies.Significance: These findings demonstrate that a combined approach of transcriptomics and insertional mutagenesis in vivo is an effective method for identifying potential targets to overcome resistance to therapy in the clinic. Cancer Res; 78(19); 5668-79. ©2018 AACR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily G, Member 2 / metabolism
  • Animals
  • Benzamides / chemistry*
  • Carcinoma, Lobular / drug therapy
  • Cell Line, Tumor
  • DNA Transposable Elements*
  • Drug Resistance, Neoplasm*
  • Female
  • Gene Amplification
  • Humans
  • MAP Kinase Signaling System
  • Mice
  • Mutagenesis*
  • Mutation
  • Neoplasm Invasiveness
  • Neoplasm Proteins / metabolism
  • Neoplasm Transplantation
  • Piperazines / chemistry*
  • Pyrazoles / chemistry*
  • Receptor, Fibroblast Growth Factor, Type 1 / metabolism
  • Receptor, Fibroblast Growth Factor, Type 2 / antagonists & inhibitors*
  • Sequence Analysis, RNA
  • Transcriptome
  • p120 GTPase Activating Protein / metabolism


  • ABCG2 protein, human
  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • AZD4547
  • Benzamides
  • DNA Transposable Elements
  • Neoplasm Proteins
  • Piperazines
  • Pyrazoles
  • RASA1 protein, human
  • p120 GTPase Activating Protein
  • FGFR1 protein, human
  • FGFR2 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1
  • Receptor, Fibroblast Growth Factor, Type 2