Evaluation of the Time- and Dose-Dependent Toxicity of Sunitinib Using a 3-D Human Hepatic Spheroid Model

Abstract ID 24159 Poster Board 23 Sunitinib is a tyrosine kinase inhibitor (TKI) used to treat cancers such as imatinib-resistant gastrointestinal stromal tumors. This TKI has been associated with hepatotoxicity in some patients taking the drug, and numerous studies have been conducted in order to test the mechanisms of hepatotoxicity associated with sunitinib. The goal of this study was to evaluate the time- and dose-dependent toxicity of sunitinib using a 3-D human hepatic spheroid model. Cryopreserved human hepatocytes from a single donor were plated in a 384-well plate and allowed to form spheroids over 6 days in culture. After spheroid formation, cells were treated with varying concentrations of sunitinib (0, 0.2, 1, 2, 10, and 50 μM) and acetaminophen (APAP, 0, 0.1, 0.5, 1, 5, 10 mM) as a positive control. Cells were dosed every 2-3 days over the 21-day experiment period. Cell viability and function were assessed by measuring ATP release and urea production using the CellTiter-Glo 3D Cell Viability assay and the QuantiChrom Urea Assay Kit, respectively. Assays were conducted on days 7, 14, and 21 after the initial day of plating (day 0). The results from the ATP and urea assays on days 14 and 21, when normalized to solvent control, showed an overall dose-dependent reduction in ATP and urea levels in spheroids treated with sunitinib and APAP. We believe these data indicate that 3-D hepatic spheroid models can be used to observe the hepatotoxic effects of sunitinib, at least through the observation of ATP levels and urea production. Future studies will focus on optimizing additional assays, such as the GSH-Glo™ Glutathione Assay, to determine the mechanisms of sunitinib-induced toxicity in the 3-D hepatic spheroid model. This research is supported in part by the National Institutes of Health National Institute of General Medical Sciences [Grant R35GM143044] and by the University Cancer Research Fund of the University of North Carolina at Chapel Hill. Research reported in this abstract is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the University of North Carolina at Chapel Hill.