Abstract | INTRODUCTION: METHODS: A lung adenocarcinoma patient-derived xenograft model (PHLC12) with wild-type and nonamplified EGFR was tested for response to EGFR tyrosine kinase inhibitors (TKIs). A cell line derived from this model (X12CL) was also used to evaluate drug sensitivity and to identify potential drivers by small interfering RNA knockdown. Kinase assays were used to test direct targeting of the candidate driver by the EGFR TKIs. Structural modeling including, molecular dynamics simulations, and binding assays were conducted to explore the mechanism of off-target inhibition by EGFR TKIs on the model 12 driver. RESULTS: Both patient-derived xenograft PHLC12 and the X12CL cell line were sensitive to multiple EGFR TKIs. The BRAFG469V mutation was found to be the only known oncogenic mutation in this model. Small interfering RNA knockdown of BRAF, but not the EGFR, killed X12CL, confirming BRAFG469V as the oncogenic driver. Kinase activity of the BRAF protein isolated from X12CL was inhibited by treatment with the EGFR TKIs gefitinib and osimertinib, and expression of BRAFG469V in non-EGFR-expressing NR6 cells promoted growth in low serum condition, which was also sensitive to EGFR TKIs. Structural modeling, molecular dynamic simulations, and in vitro binding assays support BRAFG469V being a direct target of the TKIs. CONCLUSIONS: Clinically approved EGFR TKIs can be repurposed to treat patients with non-small cell lung cancer harboring the BRAFG469V mutation.
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Authors | Ku-Geng Huo, Hirotsugu Notsuda, Zhenhao Fang, Ningdi Feng Liu, Teklab Gebregiworgis, Quan Li, Nhu-An Pham, Ming Li, Ni Liu, Frances A Shepherd, Christopher B Marshall, Mitsuhiko Ikura, Nadeem Moghal, Ming-Sound Tsao |
Journal | Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer
(J Thorac Oncol)
Vol. 17
Issue 2
Pg. 277-288
(02 2022)
ISSN: 1556-1380 [Electronic] United States |
PMID | 34648945
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2021 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved. |
Chemical References |
- Protein Kinase Inhibitors
- EGFR protein, human
- ErbB Receptors
- BRAF protein, human
- Proto-Oncogene Proteins B-raf
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Topics |
- Carcinoma, Non-Small-Cell Lung
(drug therapy, genetics, pathology)
- Drug Resistance, Neoplasm
(genetics)
- ErbB Receptors
- Humans
- Lung Neoplasms
(drug therapy, genetics, pathology)
- Mutation
- Protein Kinase Inhibitors
(pharmacology, therapeutic use)
- Proto-Oncogene Proteins B-raf
(genetics)
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