Development of a high throughput in vitro screening platform to identify novel inducers of immunological cell death

Immunological cell death (ICD) is a form of cancer cell death induced by radiotherapy, photodynamic therapy and a few chemotherapeutic agents such as Doxorubicin, Mitoxantrone, and Oxaliplatin. Unlike apoptosis or necrosis, ICD can induce an effective immune response directed against the tumor whereby both dendritic cells and T lymphocytes are mediators of this response. Dying cancer cells recruit and activate immune cells by releasing damage-associated molecular patterns (DAMPS) that help and promote the immune response to antigenic tumor neo-epitopes. Three key DAMPS are associated with the ICD process: calreticulin exposition on the cell surface, ATP secretion and high-mobility group box 1 (HMGB1) release. In order to identify new therapeutic agents that promote ICD in malignant cells, we developed a screening strategy facilitated by an automated in vitro platform with four assays on three different tumor cell lines (human osteosarcoma U-2 OS, human breast MDA-MB-231 and murine liver Hepa 1-6). ICD inducers Doxorubicin and Mitoxantrone used as positive controls increased ATP secretion by 2 to 10-fold at a non-cytotoxic dose after 72 hours incubation on the three cell lines. Both compounds also increased calreticulin exposition by 2 to 4-fold (determined by immunofluorescence using the Operetta High-Content Imaging System) and HMGB1 release by two-fold on the three cell lines. Here we will present recent data from the screening of Oncodesign9s Nanocyclix® library using this platform to identify novel ICD inducers. Citation Format: Didier Grillot, Akanksha Gangar, Raphaelle Guillard-Huet, Eric Boursier, Florent Potvain, Guillaume Serin, Jean-Francois Mirjolet. Development of a high throughput in vitro screening platform to identify novel inducers of immunological cell death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 782.