EGFR-TKI-induced HSP70 degradation and BER suppression facilitate the occurrence of the EGFR T790 M resistant mutation in lung cancer cells

Xiang Cao, Yi Zhou, Hongfang Sun, Miao Xu, Xiaowen Bi, Zhihui Zhao, Binghui Shen, Fengyi Wan, Zhuan Hong, Lei Lan, Lan Luo, Zhigang Guo, Zhimin Yin

Research output: Contribution to journalArticlepeer-review

Abstract

Non-small cell lung cancer (NSCLC) patients harboring EGFR-activating mutations initially respond to EGFR tyrosine kinase inhibitors (EGFR-TKIs) and have shown favorable outcomes. However, acquired drug resistance to EGFR-TKIs develops in almost all patients mainly due to the EGFR T790 M mutation. Here, we show that treatment with low-dose EGFR-TKI results in the emergence of the EGFR T790 M mutation and in the reduction of HSP70 protein levels in HCC827 cells. Erlotinib treatment inhibits HSP70 phosphorylation at tyrosine 41 and increases HSP70 ubiquitination, resulting in HSP70 degradation. We show that EGFR-TKI treatment causes increased DNA damage and enhanced gene mutation rates, which are secondary to the EGFR-TKI-induced reduction of HSP70 protein. Importantly, HSP70 overexpression delays the occurrence of Erlotinib-induced EGFR T790 M mutation. We further demonstrate that HSP70 interacts with multiple enzymes in the base excision repair (BER) pathway and promotes not only the efficiency but also the fidelity of BER. Collectively, our findings show that EGFR-TKI treatment facilitates gene mutation and the emergence of EGFR T790 M secondary mutation by the attenuation of BER via induction of HSP70 protein degradation.

Original languageEnglish (US)
Pages (from-to)84-96
Number of pages13
JournalCancer Letters
Volume424
DOIs
StatePublished - Jun 28 2018

Keywords

  • Base excision repair
  • EGFR T790 M mutation
  • EGFR-TKI
  • HSP70 phosphorylation and degradation
  • Lung cancer

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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