Preclinical tumor-immune modeling : For the identification of immunomodulatory drugs

For a long time, the field of cancer research was dominated by a tumor cell-centric view. That, however, changed once it became recognized that medical cancer treatment is largely influenced by the combined effect exerted on both cancer and immune cells. In this work, we aimed to develop and apply preclinical model systems for the identification and evaluation of immunomodulatory anti-cancer agents. In Paper I, we employed single-cell RNA sequencing (scRNA-seq) to investigate immunological effects of trifluridine (FTD), a nucleoside analogue used for the treatment of colorectal cancer (CRC). The study revealed that while FTD induces immunogenic cell death (ICD), it may also attenuate T cell-mediated antitumor responses. In paper II and III, we developed and applied a phenotypic screening platform based on a miniaturized tumor-immune model. In paper II, aiming to identify immunological effects of clinical relevance and provide a reference point for screening novel compound libraries, the model system was used to assess a broad panel of standard anticancer agents. In paper III, the platform was used to screen a drug library containing 1280 small molecule drugs, all approved by the FDA or other agencies. Using this approach, statins were identified as enhancers of immune cell-mediated cancer cell killing. Finally, in paper IV, we developed the immuno-oncology hollow fiber assay (HFA) with the goal of bridging the gap between cell based in vitro assays and more complex mouse models for evaluation of immuno-oncological agents. The HFA is an in vivo assay in which semipermeable fibers are filled with cancer cells and implanted in rodents. We further developed the HFA to incorporate both cancer and immune cells. This novel assay demonstrated the potential to capture immune-mediated cancer cell killing in vivo within a matter of days. Collectively, this work provides a research approach for immuno-oncology drug screening, in vitro validation, and initial in vivo evaluation.