Abstract 5528: Identification of compounds modifying radiation-therapy using a 3D-microtissue technology.

Abstract

Abstract The two key issues in chemo- and radiation therapy is the development of tumor resistance as well as toxic effects on normal tissue. In this sense new strategies are required to increase efficacy of radiation to improve the therapeutic impact and reduce toxicological side effects. The performance of 3D cell culture systems over classical 2D culture systems has been shown to provide a closer representation of tissue-level biology. This has led to the rapid adoption of 3D systems for both drug discovery and toxicology. InSphero has developed a highly reproducible hanging drop technology able to generate monotypic cell spheroids (microtissues) in a 96-well format. The innovative 3D-microtissue plate technology has been adapted for analysis of the cellular response of radioresistant T47D breast cancer cells to combined radio-chemotherapy (RCTx). We have validated the model by comparing the treatment of microtissues with 10 different chemotherapeutic compounds, each tested alone and in combination with an acute 2Gy radiation exposure. The T47D cells were stably transduced with GFP-lentiviral vector enabling faster high throughput quantification of 3D microtissue growth assessment using an Operetta working Software and detection system ‘Harmony 3.0’ (PerkinElmer, USA). We studied the ability of RCTx to modify 3D-microtissue growth 3, 6 and 10 days after treatment. Results for five compounds (Actinomycin D, Staurosporine, Docetaxel, Doxorubicin and Vinblastine) showed that the IC50 values were improved by the addition of the single 2Gy radiation dose, indicating that they are capable of inducing a radiosensitation effect on radioresistant breast cancer cells. Panels of commercial secondary functional assays were adapted to the 3D-microtissue high throughput assay. Cellular viability and cytotoxicity were measured directly in microtissues using the CellTiter-Glo Reagent (Promega, USA). Apoptosis was measured using an ELISA based M30-Apoptosense assay (TECOmedical AG, Switzerland). These results all confirm that the assay operated with the 3D-microtissue model system is able to detect compounds that modulate tumors cell survival after irradiation. Citation Format: Natasa Anastasov, Ines Höfig, Jan Lichtenberg, Simon Stroebel, Michael Salomon, Christian Thirion, Jens Kelm, Michael J. Atkinson. Identification of compounds modifying radiation-therapy using a 3D-microtissue technology. [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 5528. doi:10.1158/1538-7445.AM2013-5528