1. Molecular Landscape of Acquired Resistance to Targeted Therapy Combinations in BRAF-Mutant Colorectal Cancer
- Author
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Andrea Sartore-Bianchi, Margherita Gallicchio, Erin M. Sennott, Alice Bartolini, Federica Di Nicolantonio, Julieta Grasselli, Valentina Boscaro, Alberto Bardelli, Jan H.M. Schellens, Giovanni Crisafulli, Salvatore Siena, Jason T. Godfrey, Andrea Cassingena, Jeffrey A. Engelman, Genny Filiciotto, Giorgio Corti, Giulia Siravegna, Mauro Truini, Josep Tabernero, Giulia Marzolla, Michael Linnebacher, Carlotta Cancelliere, Sabrina Arena, René Bernards, Emanuele Valtorta, Ludovic Barault, Daniele Oddo, Michela Buscarino, Ryan B. Corcoran, Elena Elez, Robin M.J.M. van Geel, MUMC+: DA KFT Laboratorium (9), and RS: FHML non-thematic output
- Subjects
Proto-Oncogene Proteins B-raf ,0301 basic medicine ,MAPK/ERK pathway ,Cancer Research ,endocrine system diseases ,Colorectal cancer ,medicine.medical_treatment ,Gene Dosage ,colorectal cancer ,Drug resistance ,medicine.disease_cause ,Article ,BRAF ,ERK inhibitors ,Targeted therapy ,03 medical and health sciences ,0302 clinical medicine ,cetuximab ,medicine ,Humans ,neoplasms ,EGFR inhibitors ,drug resistance ,Cetuximab ,business.industry ,BRAF, colorectal cancer, drug resistance, cetuximab, ERK inhibitors ,Gene Amplification ,Cancer ,medicine.disease ,digestive system diseases ,3. Good health ,030104 developmental biology ,Oncology ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Cancer research ,KRAS ,Colorectal Neoplasms ,business ,Signal Transduction ,medicine.drug - Abstract
Although recent clinical trials of BRAF inhibitor combinations have demonstrated improved efficacy in BRAF-mutant colorectal cancer, emergence of acquired resistance limits clinical benefit. Here, we undertook a comprehensive effort to define mechanisms underlying drug resistance with the goal of guiding development of therapeutic strategies to overcome this limitation. We generated a broad panel of BRAF-mutant resistant cell line models across seven different clinically relevant drug combinations. Combinatorial drug treatments were able to abrogate ERK1/2 phosphorylation in parental-sensitive cells, but not in their resistant counterparts, indicating that resistant cells escaped drug treatments through one or more mechanisms leading to biochemical reactivation of the MAPK signaling pathway. Genotyping of resistant cells identified gene amplification of EGFR, KRAS, and mutant BRAF, as well as acquired mutations in KRAS, EGFR, and MAP2K1. These mechanisms were clinically relevant, as we identified emergence of a KRAS G12C mutation and increase of mutant BRAF V600E allele frequency in the circulating tumor DNA of a patient at relapse from combined treatment with BRAF and MEK inhibitors. To identify therapeutic combinations capable of overcoming drug resistance, we performed a systematic assessment of candidate therapies across the panel of resistant cell lines. Independent of the molecular alteration acquired upon drug pressure, most resistant cells retained sensitivity to vertical MAPK pathway suppression when combinations of ERK, BRAF, and EGFR inhibitors were applied. These therapeutic combinations represent promising strategies for future clinical trials in BRAF-mutant colorectal cancer. Cancer Res; 76(15); 4504–15. ©2016 AACR.
- Published
- 2016