Abstract 1816: Mechanism of resistance to single treatment with MET inhibitor in EGFR-mutant lung cancer cell secondarily acquiring c-MET amplification

Abstract

Abstract Amplification in c-MET is the second most common mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI) in lung cancer harboring activated EGFR mutations. An acquired resistance mechanism to single treatment with MET kinase inhibitor remains unknown. In this study, we modeled acquired resistance to experimental type I MET kinase inhibitor PHA66572 in MET-amplified HCC827 lung cancer cell line, which was established under chronic exposure to gefitinib in our lab. We found that reactivation of the EGFR pathway emerges as a resistance mechanism in MET secondarily amplified EGFR-mutant lung cancer cells after prolonged exposure to PHA66572. Any gene alteration influencing sensitivity to the drugs was not observed. Long treatment with only MET inhibitor resulted in partial resensitization to EGFR-TKI in these resistant lung cancer cells. Thus, the combination of gefitinib and PHA66572 could completely suppress the cell growth. Our findings support an intimate relationship between the EGFR and MET signaling pathways in HCC827 lung cancer cell line. Citation Format: Youngjoo Lee, Yu-Ra Choi. Mechanism of resistance to single treatment with MET inhibitor in EGFR-mutant lung cancer cell secondarily acquiring c-MET amplification [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1816.