Abstract 4538: A novel assay platform for the detection of kinase-inhibitor binding in intact mammalian cells.

Kinase binding assays have become an integral part of inhibitor characterization. These tools have been applied in KINOME-wide screening systems as well as the detailed characterization of inhibitor residence time for lead optimization and MOA studies. However in cells, assays are limited to monitoring kinase activity and downstream substrate phosphorylation events. Although these types of cellular assays are critical to move programs forward, their ability to characterize inhibitor function is limited, requires targeted antibody reagents, and knowledge of specific substrates which are often not available. To circumvent these issues and apply the power of binding assays to a cellular format we have devised a method for monitoring compound binding to kinase targets in intact mammalian cells termed InCELL Hunter. The assay is shown to retain the benefits of cellular assays such as assessing compound permeability, toxicity, and target engagement; while exhibiting the generic applicability of a kinase binding assay. The InCELL hunter assay correctly describes type I, type II, and Type III inhibitors with the expected rank order cellular potencies. The assay is activity and substrate independent making it amenable to previously intractable targets and provides novel cellular information that complements both biochemical and existing cellular formats. Citation Format: Abhi Saharia, William Raab, Daniel Bassoni, Jeremy Hunt, Daniel K. Treiber, Tom Wehrmann. A novel assay platform for the detection of kinase-inhibitor binding in intact mammalian cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4538. doi:10.1158/1538-7445.AM2013-4538