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Updated: May 26, 2026

Establishing Dual Resistance to EGFR-TKI and MET-TKI in Lung Adenocarcinoma Cells In Vitro with a 2-step Dose-escalation Procedure
Published on: August 11, 2017
The EGFR T790M mutation in acquired resistance to an irreversible second-generation EGFR inhibitor
Youngwook Kim1, Jeonghun Ko, ZhengYun Cui
1Medical Nano-Element Development Center, Samsung Biomedical Research Institute, Seoul, Korea.
Abstract:
Molecular target therapies using first-generation, reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), such as gefitinib or erlotinib, have been shown to be effective for patients with non-small cell lung cancer (NSCLC) who harbor activating mutations in EGFR. However, these patients eventually develop resistance to the reversible TKIs, and this has led to the development of second-generation, irreversible EGFR inhibitors. Currently, the mechanism of acquired resistance to irreversible EGFR inhibitors is not clear. Using an in vitro cell culture system, we modeled the acquired resistance to first-line treatment with second-generation EGFR-TKIs using an EGFR-mutant NSCLC cell line. Here, we report a mechanism of resistance involving T790M secondary mutation as well as a corresponding clinical case. The results of these findings suggest that inhibition of EGFR by currently available second-generation EGFR-TKIs may not be sufficient to physiologically prevent the emergence of cells that are still dependent on EGFR signaling. This finding bears important implications on the limitations of currently available second-generation EGFR-TKIs.
Insights
Acquired resistance to irreversible EGFR inhibitors in non-small cell lung cancer (NSCLC) can occur through secondary T790M mutations. Current second-generation EGFR inhibitors may not fully prevent EGFR-dependent signaling in resistant cells.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- First-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective for EGFR-mutant non-small cell lung cancer (NSCLC).
- Acquired resistance to these reversible TKIs necessitates the development of second-generation, irreversible EGFR inhibitors.
- The mechanisms underlying acquired resistance to irreversible EGFR inhibitors remain largely unclear.
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