Targeting LRIG2 overcomes resistance to EGFR inhibitor in glioblastoma by modulating GAS6/AXL/SRC signaling

Cancer Gene Ther. 2020 Dec;27(12):878-897. doi: 10.1038/s41417-020-0163-1. Epub 2020 Jan 28.

Abstract

Epidermal growth factor receptor (EGFR) gene amplification and mutation occurs most frequently in glioblastoma (GBM). However, EGFR-tyrosine kinase inhibitors (TKIs), including gefitinib, have not yet shown clear clinical benefit and the underlying mechanisms remain largely unexplored. We previously demonstrated that LRIG2 plays a protumorigenic role and functions as a modulator of multiple oncogenic receptor tyrosine kinases (RTKs) in GBM. We therefore hypothesized that LRIG2 might mediate the resistance to EGFR inhibitor through modulating other RTK signaling. In this study, we report that LRIG2 is induced by EGFR inhibitor in gefitinib-treated GBM xenografts or cell lines and promotes resistance to EGFR inhibition by driving cell cycle progression and inhibiting apoptosis in GBM cells. Mechanistically, LRIG2 increases the secretion of growth-arrest specific 6 (GAS6) and stabilizes AXL by preventing its proteasome-mediated degradation, leading to enhancement of the gefitinib-induced activation of AXL and then reactivation of the gefitinib-inhibited SRC. Targeting LRIG2 significantly sensitizes the GBM cells to gefitinib, and inhibition of the downstream GAS6/AXL/SRC signaling abrogates LRIG2-mediated gefitinib resistance in vitro and in vivo. Collectively, our findings uncover a novel mechanism in resistance to EGFR inhibition and provide a potential therapeutic strategy to overcome resistance to EGFR inhibition in GBM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axl Receptor Tyrosine Kinase
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drug Resistance, Neoplasm
  • ErbB Receptors / antagonists & inhibitors
  • Gefitinib / pharmacology
  • Glioblastoma / drug therapy*
  • Glioblastoma / genetics
  • Glioblastoma / metabolism
  • Humans
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Mice, Nude
  • Molecular Targeted Therapy
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins / metabolism*
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Signal Transduction / drug effects
  • Up-Regulation / drug effects
  • Xenograft Model Antitumor Assays
  • src-Family Kinases / metabolism*

Substances

  • Intercellular Signaling Peptides and Proteins
  • LRIG2 protein, human
  • Membrane Glycoproteins
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • growth arrest-specific protein 6
  • EGFR protein, human
  • ErbB Receptors
  • Receptor Protein-Tyrosine Kinases
  • src-Family Kinases
  • Gefitinib
  • Axl Receptor Tyrosine Kinase