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 6

Inhibition of TNF enhances sensitivity of NSCLC cells with EGFR activating mutations to EGFR inhibition.

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Inhibition of TNF enhances sensitivity of NSCLC cells with EGFR activati...
(A and B) AlamarBlue assay in HCC827 or H3255 cells. TNFR1 was silenced using siRNA, and 48 hours later cells were exposed to erlotinib for 72 hours. (C) Silencing of TNFR1 was confirmed by Western blot. Results are representative of 3 independent replicates. (D and E) Thalidomide sensitizes HCC827 and H3255 cells to EGFR inhibition. Thalidomide (5 μg/ml) and erlotinib were added concurrently, and AlamarBlue assay was done after 72 hours. (F and G) Similar experiments were done using etanercept (100 μg/ml) and erlotinib in HCC827 and H3255 cells. (H and I) HCC827 and H3255 cells were treated with afatinib with or without thalidomide for 72 hours, followed by AlamarBlue assay. (J and K) Similar experiments were performed in HCC827 and H3255 cells with afatinib and etanercept. The concentration of erlotinib or afatinib was 10 nM in A–K. (L and M) EGFR-mutant NSCLC cells were seeded in 6-well plates at 1,000 cells per well, and incubated with 5 μg/ml thalidomide and/or erlotinib 1 nM. Fourteen days later, cell colonies were fixed by 100% methanol and then stained by 0.5% crystal violet in 25% methanol. Images were captured by a scanner, and colony counting was processed by ImageJ. Data are presented as the average percentage of untreated colonies ± SEM from 3 experiments. (N and O) Exogenous TNF protects H3255 and HCC827 from all erlotinib-induced cell death. Cells were exposed to erlotinib (100 nM) with or without TNF (1 ng/ml). Cell viability was determined 72 hours later using AlamarBlue assay. Data represent the mean percentage of control ± SEM. n = 3 biologically independent experimental replicates (A, B, and D–O). *P < 0.05, **P < 0.01, ***P < 0.001, by Student’s t test.