PROJECT SUMMARY – Core 2: Human Specimen and Organoid Core Patients diagnosed with pancreatic ductal adenocarcinoma (PDA) often fail to respond to therapeutic intervention or rapidly develop resistance to treatment. To study mechanisms of therapeutic resistance, the assembled P01 research team will utilize a large and representative cohort of PDA patient-derived three-dimensional organoid models (PDOs). Organoids accurately recapitulate the genomic, transcriptomic, and phenotypic characteristics of human PDA and enable predictive profiling of drug response in a heterogenous patient-cohort. The Human Specimen and Organoid Core (HSO Core) will facilitate the elucidation of mechanisms of resistance in collaboration with each Research Project. The HSO Core will test numerous novel therapeutic combinations to determine effective and synergistic strategies. The Core will provide a powerful patient-derived organotypic tumor slice platform for ex vivo mechanistic studies. In addition, the HSO Core will generate organoid co-cultures with key stromal cells and will develop organoids from genetically engineered mouse (GEM) models that develop spontaneous PDA. The overall goal of the HSO Core is to support each Project in the discovery and validation of effective therapeutic strategies to overcome treatment resistance. To accomplish this, the HSO Core has three Aims. In Aim 1, The Core will provide methodology expertise and valuable PDO models tailored to each individual Project. Novel therapeutic combinations that include drugs such as Entinostat (Project 1) and ULK1/2 inhibitors (Project 3) will be profiled using a pharmacotyping assay that takes advantage of the Core’s heterogenous cohort of organoids. Combinations will be evaluated and synergies mathematically defined. Existing DNA/RNA-sequencing datasets will be leveraged to discover predictive signatures of drug sensitivity and resistance. In Aim 2, the Core will provide access to an organotypic living tumor slice model that preserves the neoplastic and stromal cellular compartments of PDA. Methodologies developed by the HSO Core allow for ex vivo culture up to 7 days, enabling the perturbation and characterization of cell to cell signaling networks. Further, the Core will develop co-culture systems that incorporate epithelial organoids, fibroblasts, and immune cells in collaboration with Projects 2. Finally in Aim 3, the Core will collaborate with the Mouse Models Core to generate mouse-derived organoids from previously unavailable GEM models and develop organoid resources to facilitate the workflow of the Research Projects and Cores.