397614 Efficacy of Select Viability Assays in Multicellular Tumor Spheroid Culture

Monday, November 17, 2014
Galleria Exhibit Hall (Hilton Atlanta)
Jonathan F. Coburn, Sarah E. Patterson, Anastasia K. Hauser, Kimberly W. Anderson and J. Zach Hilt, Chemical and Materials Engineering, University of Kentucky, Lexington, KY

Multicellular tumor spheroids (MCTS) mimic the physiological state of tumors in vivo more accurately than do cell monolayers. Essential tumor characteristics such as hypoxia, drug resistance, and the extracellular matrix may collectively be included in cancer therapy screening through the use of this complex in vitro model. Attendant with the increased complexity of the MCTS model is increased difficulty of application, particularly in assaying MCTS viability. Whereas other studies have addressed this issue by validating single viability assays or developing new assays for MCTS use, this study endeavors to compare the efficacy of several traditional monolayer viability assays in MCTS culture. Acid phosphatase and resazurin assays were evaluated for response to varying number of spheroids and varying spheroid seeding density, with the acid phosphatase assay resulting in a more consistent response to both. These assays and a live/dead (calcein/ethidium homodimer-1) assay were used to evaluate treatment with the chemotherapeutic cisplatin. In this study, the response of dissociated MCTS and intact MCTS to each of the assays was compared. Based on these preliminary results, the acid phosphatase assay appears to provide the best balance between consistent results and usefulness for high throughput studies. Consequently, the acid phosphatase assay was applied in a proof of concept study to evaluate combination hyperthermia and cisplatin treatment. The results presented herein contribute to the development and validation of assays necessary to the application of MCTS in cancer research.

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