The measurement of drug - target interaction in the cellular context is critical to many drug development programs. The Cellular Thermal Stability Assay (CETSA®) represents an established broadly applicable method for measuring drug target interaction. However, in its classic format, it has some limitations that make it difficult to scale to the throughput typically required for a drug development project. It requires heating samples to different temperatures and centrifugation and / or filtration steps which limit throughput. The HSP90 Inhibitor Protein Stability Assay (HIPStA) is a novel method for measuring drug target interaction. Like CETSA®, HIPStA is based on the premise that the binding of a ligand to a target protein can influence that protein's stability. Instead of using heat to destabilize a protein, HIPStA uses a Heat Shock Protein 90 inhibitor (HSP90i) to cause protein instability. Instead of scanning a range of different temperatures to establish a thermal denaturation curve, HIPStA applies a range of concentrations of an HSP90i to determine an HSP90i induced denaturation curve, and ultimately measures the ability of a compound to stabilize a protein. We present data demonstrating the proof of concept for the HIPStA method, using 3 different classes of drug discovery targets: Receptor tyrosine kinases, Nuclear Hormone Receptors and Cytoplasmic Protein Kinases. HIPStA represents a scale-able method for detecting drug-target interaction in cells.

Citation Format: Kelvin F. Cho, Christopher Rose, Taylur Ma, Donald Kirkpatrick, Robert A. Blake. HIPStA, a high-throughput alternative to CETSA® [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 775.