Targeting the degradation of AXL receptor tyrosine kinase to overcome resistance in gefitinib-resistant non-small cell lung cancer

Oncotarget. 2015 Apr 30;6(12):10146-60. doi: 10.18632/oncotarget.3380.


Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, remains a major problem in non-small cell lung cancer (NSCLC) treatment. Increased activation of AXL has been identified as a novel mechanism for acquired resistance to EGFR-TKIs in NSCLC treatment. However, the cause of uncontrolled AXL expression is not fully understood. Here, we first demonstrate that AXL is overexpressed in an acquired gefitinib-resistant cell line (H292-Gef) as a result of slow turnover and that AXL is degraded by presenilin-dependent regulated intramembrane proteolysis (PS-RIP). Based on the findings, we attempted to enhance AXL degradation to overcome acquired gefitinib-resistance by the treatment of gefitinib-resistant NSCLC cells with yuanhuadine (YD), a potent antitumor agent in NSCLC. Treatment with YD effectively suppressed the cancer cell survival in vitro and in vivo. Mechanistically, YD accelerated the turnover of AXL by PS-RIP and resulted in the down-regulation of the full-length AXL. Therefore, the modulation of the proteolytic process through degradation of overexpressed AXL may be an attractive therapeutic strategy for the treatment of NSCLC and EGFR-TKI-resistant NSCLC.

Keywords: AXL; EGFR-TKI resistance; NSCLC; PS-RIP; yuanhuadine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Apoptosis / drug effects
  • Axl Receptor Tyrosine Kinase
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / enzymology
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drug Resistance, Neoplasm
  • Female
  • Gefitinib
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / enzymology
  • Lung Neoplasms / genetics
  • Lung Neoplasms / pathology
  • Mice
  • Mice, Nude
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins / metabolism*
  • Quinazolines / pharmacology*
  • Random Allocation
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Quinazolines
  • Receptor Protein-Tyrosine Kinases
  • Gefitinib
  • Axl Receptor Tyrosine Kinase