1. Quantifying single-cell ERK dynamics in colorectal cancer organoids reveals EGFR as an amplifier of oncogenic MAPK pathway signalling.
- Author
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Ponsioen B, Post JB, Buissant des Amorie JR, Laskaris D, van Ineveld RL, Kersten S, Bertotti A, Sassi F, Sipieter F, Cappe B, Mertens S, Verlaan-Klink I, Boj SF, Vries RGJ, Rehmann H, Vandenabeele P, Riquet FB, Trusolino L, Bos JL, and Snippert HJG
- Subjects
- Cell Line, Tumor, Colorectal Neoplasms genetics, Colorectal Neoplasms pathology, ErbB Receptors genetics, Gene Expression Regulation, Neoplastic drug effects, Humans, MAP Kinase Signaling System drug effects, Mitogen-Activated Protein Kinase Kinases genetics, Mutation, Organoids metabolism, Organoids pathology, Single-Cell Analysis, Colorectal Neoplasms drug therapy, Protein Kinase Inhibitors pharmacology, Proto-Oncogene Proteins B-raf genetics, Proto-Oncogene Proteins p21(ras) genetics
- Abstract
Direct targeting of the downstream mitogen-activated protein kinase (MAPK) pathway to suppress extracellular-regulated kinase (ERK) activation in KRAS and BRAF mutant colorectal cancer (CRC) has proven clinically unsuccessful, but promising results have been obtained with combination therapies including epidermal growth factor receptor (EGFR) inhibition. To elucidate the interplay between EGF signalling and ERK activation in tumours, we used patient-derived organoids (PDOs) from KRAS and BRAF mutant CRCs. PDOs resemble in vivo tumours, model treatment response and are compatible with live-cell microscopy. We established real-time, quantitative drug response assessment in PDOs with single-cell resolution, using our improved fluorescence resonance energy transfer (FRET)-based ERK biosensor EKAREN5. We show that oncogene-driven signalling is strikingly limited without EGFR activity and insufficient to sustain full proliferative potential. In PDOs and in vivo, upstream EGFR activity rigorously amplifies signal transduction efficiency in KRAS or BRAF mutant MAPK pathways. Our data provide a mechanistic understanding of the effectivity of EGFR inhibitors within combination therapies against KRAS and BRAF mutant CRC.
- Published
- 2021
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