TNF-driven adaptive response mediates resistance to EGFR inhibition in lung cancer
Ke Gong, … , Dawen Zhao, Amyn A. Habib
Ke Gong, … , Dawen Zhao, Amyn A. Habib
Published April 3, 2018
Citation Information: J Clin Invest. 2018;128(6):2500-2518. https://doi.org/10.1172/JCI96148.
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Research Article

TNF-driven adaptive response mediates resistance to EGFR inhibition in lung cancer

Abstract

Although aberrant EGFR signaling is widespread in cancer, EGFR inhibition is effective only in a subset of non–small cell lung cancer (NSCLC) with EGFR activating mutations. A majority of NSCLCs express EGFR wild type (EGFRwt) and do not respond to EGFR inhibition. TNF is a major mediator of inflammation-induced cancer. We find that a rapid increase in TNF level is a universal adaptive response to EGFR inhibition in NSCLC, regardless of EGFR status. EGFR signaling actively suppresses TNF mRNA levels by inducing expression of miR-21, resulting in decreased TNF mRNA stability. Conversely, EGFR inhibition results in loss of miR-21 and increased TNF mRNA stability. In addition, TNF-induced NF-κB activation leads to increased TNF transcription in a feed-forward loop. Inhibition of TNF signaling renders EGFRwt-expressing NSCLC cell lines and an EGFRwt patient-derived xenograft (PDX) model highly sensitive to EGFR inhibition. In EGFR-mutant oncogene-addicted cells, blocking TNF enhances the effectiveness of EGFR inhibition. EGFR plus TNF inhibition is also effective in NSCLC with acquired resistance to EGFR inhibition. We suggest concomitant EGFR and TNF inhibition as a potentially new treatment approach that could be beneficial for a majority of lung cancer patients.

Authors

Ke Gong, Gao Guo, David E. Gerber, Boning Gao, Michael Peyton, Chun Huang, John D. Minna, Kimmo J. Hatanpaa, Kemp Kernstine, Ling Cai, Yang Xie, Hong Zhu, Farjana J. Fattah, Shanrong Zhang, Masaya Takahashi, Bipasha Mukherjee, Sandeep Burma, Jonathan Dowell, Kathryn Dao, Vassiliki A. Papadimitrakopoulou, Victor Olivas, Trever G. Bivona, Dawen Zhao, Amyn A. Habib

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Figure 3

EGFR inhibition induces a TNF-dependent activation of NF-κB.

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EGFR inhibition induces a TNF-dependent activation of NF-κB. (A) HCC827,...
(A) HCC827, H3255, A549, and H441 cells were exposed to erlotinib (100 nM for EGFR-mutant and 1 μM for EGFRwt cells) for 24 hours followed by a dual luciferase reporter assay. Renilla luciferase was used as an internal control. (B) Cells were treated with erlotinib at various time points followed by preparation of cell lysates and Western blot with an IκBα antibody. Western blots are representative of at least 3 independent replicates. The quantified values reflect the ratios of IκBα/actin. (C) siRNA knockdown of TNFR1 was performed in HCC827 cells followed by transfection of cells with an NF-κB luciferase reporter and exposure of cells to erlotinib, followed by a reporter assay. Silencing of TNFR1 was confirmed with a Western blot. (D) A similar experiment was undertaken in A549 cells, and TNFR1 silencing was confirmed with a Western blot. Western blots shown in C and D are representative of at least 3 independent replicates. (E) The TNF-blocking drug etanercept was used at a concentration of 100 μg/ml along with erlotinib for 24 hours followed by a reporter assay in HCC827 cells. (F) A similar experiment was conducted in A549 cells. (G and H) Reporter assay for NF-κB in cells treated with erlotinib in the presence or absence of thalidomide (5 μg/ml) for 24 hours. (I and J) HCC827 and A549 cells were treated with exogenous TNF (10 ng/ml) with or without thalidomide for 24 hours followed by a reporter assay for NF-κB transcriptional activity. In luciferase assays, cells were transfected with reporter 24 hours before exposure to erlotinib. Data represent the mean ± SEM. n = 3 biologically independent experimental replicates (A and C–J). *P < 0.05, **P < 0.01, by Student’s t test. Erl, erlotinib; Thal, thalidomide.