Src mediates ERK reactivation in gefitinib resistance in non-small cell lung cancer

Nobuaki Ochi, Nagio Takigawa, Daijiro Harada, Masayuki Yasugi, Eiki Ichihara, Katsuyuki Hotta, Masahiro Tabata, Mitsune Tanimoto, Katsuyuki Kiura

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

To study epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) resistance mechanisms, we established a novel gefitinib-resistant lung cancer cell line derived from an EGFR-mutant non-small cell lung cancer cell line (PC-9) pretreated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (designated PC9-GR). We found that gefitinib substantially suppressed the EGFR signaling pathway, whereas ERK was reactivated after several hours in PC9-GR but not in PC-9. The combination of gefitinib with ERK inhibition (by U0126) restored gefitinib susceptibility in PC9-GR, but PI3K-Akt inhibition with LY294002 did not. Although the levels of phosphorylated Src were up-regulated simultaneously with ERK reactivation, neither ERK suppression using U0126 nor an ERK-specific siRNA induced Src phosphorylation. Furthermore, dual inhibition of EGFR and Src restored gefitinib sensitivity in PC9-GR in vitro and in vivo. In conclusion, our results indicate that Src-mediated ERK reactivation may play a role in a novel gefitinib resistance mechanism, and that the combined use of gefitinib with a Src inhibitor may be a potent strategy to overcome this resistance.

Original languageEnglish
Pages (from-to)168-177
Number of pages10
JournalExperimental Cell Research
Volume322
Issue number1
DOIs
Publication statusPublished - Mar 10 2014

Keywords

  • EGFR
  • ERK
  • Gefitinib
  • Lung cancer
  • Resistance
  • Src

ASJC Scopus subject areas

  • Cell Biology

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