Abstract 5655: Biophysics in the cell—CETSA to study drug binding and cellular processes in cancer therapy

Abstract

Abstract A key step of the action of most drugs is their binding (engagement) of the target protein(s). However, limitations in the available methods for directly accessing this critical step have added uncertainties in many stages of drug development. We have developed a generic method for evaluating drug binding to target proteins in cells and tissues (Martinez Molina et al. Science, 341:84). The technique is based on the physical phenomenon of ligand-induced thermal stabilization of target proteins; the method is therefore called the cellular thermal shift assay (CETSA). The technique allows for the first time to directly measure the biophysical interactions between a drug and protein target in non- engineered cells and tissues. We show that using CETSA a range of critical factors for drug action can be addressed at the target engagement level, including drug transport and activation, off-target effects, drug resistance as well as drug distribution in cells, patient and animal tissues. Although CETSA was first developed for evaluating drug binding to target proteins in cells it is also useful for characterizing physiological interactions, including protein-protein, protein-metabolite and protein-nucleic acid interactions (Martinez Molina & Nordlund, Ann Rev Pharm Toxic 2016 56:141). In the proteome-wide CETSA experiment, interactions with more than 7000 proteins can be measured in parallel (Savitski, Science 2014 346;6205). This strategy therefore constitutes a novel mean for discovering key interactions determining the fate of cancer cells during therapy and resistance – interactions that can serve as biomarkers or candidates for novel drug targets in cancer therapy. Citation Format: Ying Yu Liang, Anderson Ramos, Henriette Laursen, Olga Surova, Johan Lengqvist, Sara Lööf, Anette Langebäck, Smaranda Bacanu, Jonas Bergh, Pär Nordlund. Biophysics in the cell—CETSA to study drug binding and cellular processes in cancer therapy [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 5655.