Abstract 697: Development of spheroid based high-throughput screening of cell-cell adhesion inhibitors to reverse acquired multicellular resistance

Abstract

Abstract Background: Solid tumors are more resistant to chemo- and radio-therapy than in vitro cancer cells under conventional monolayer culture condition. This phenomenon can be explained by “multicellular resistance” (MCR). It is considered that one of approach for keeping out cancer cells from acquired MCR is inhibition of cell-cell/cell-matrix adherence. Several therapeutic approaches increasing effect of chemo- and radio-therapy by preventing MCR are proposed. However, reports of the approaches are still few. Therefore, we tried to develop a spheroid-based high-throughput screening method of cell-cell adherence inhibitor, for discovery of drug capable of reversing the acquired MCR. Method: For spheroid formation, A549 cells were cultured under three-dimensional condition using NanoCulture® Plate, which is compatible with imaging and HTS systems. After 3 days culture, A549 spheroids were treated with library compounds for 4 days. To evaluate a degree of cell-cell adherence of the spheroids, we used Hypoxia Probe, which is a phosphorescence substrate for visualizing of intra-spheroid hypoxicity. And the signals were detected using Celigo® imaging cytometer. Results: In NanoCulture® Plate, A549 cells formed a number of spheroids. Intra-spheroid hypoxicity was correlated with degree of cell-cell adherence. After screening of inhibitor of cell-cell adherence without cytotoxity, several candidates were evaluated the ability as chemosensitizing agent. Combination treatment with the hit compound and anticancer drug was more effective than each drug alone. Conclusion: We developed a novel high throughput screening method of cell-cell adherence inhibitors. And we acquired several hit compounds capable of reversing the acquired MCR. Note: This abstract was not presented at the meeting. Citation Format: Kazuya Arai, Manabu Itho, Atsushi Mizuno, Hiromi Miura. Development of spheroid based high-throughput screening of cell-cell adhesion inhibitors to reverse acquired multicellular resistance. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 697. doi:10.1158/1538-7445.AM2014-697