Project Summary This application is being submitted in response to the Notice of Special Interest (NOSI) identified as NOT-CA- 24-029. Intraductal papillary mucinous neoplasms (IPMN) are premalignant lesions that can develop into invasive pancreatic ductal adenocarcinoma (PDAC). Most pancreatic premalignancies are microscopic and not identifiable by current imaging exams. The only PDAC precursor that can be diagnosed by imaging test are the IPMNs. Since not all IPMN develop into PDAC, it is critical to understand the evolution of this premalignant lesions to develop diagnostic tools to discriminate the ones that require therapeutic intervention to prevent cancer. The Parent U01 award proposes a systems biology approach, combining DNA-sequencing, RNA- sequencing and refined computational tools, to characterize the clonal evolution of IPMN by examining clinical specimens and patient derived organoid models. Although DNA- and RNA-sequencing have demonstrated power to study the evolutionary trajectory and functional impact of molecular perturbations, respectively, the bulk profiling does not allow proper interpretation of the TME composition and the cellular interactions happening within the premalignant microenvironment. Therefore, we propose a new collaboration with Dr. Luciane Kagohara to include on our systems biology approach the spatial transcriptomics analysis of human IPMN samples to examine within the tissue context the transcriptional state of the premalignant microenvironment (Aim 1) and understand the intercellular interactions that are associated with the clonal evolution of these PDAC precursors (Aim 2). This project enables further experimental and computational techniques to broaden the comprehensive investigation of PDAC progression that could identify potential signatures for early detection and therapy.