PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly tumor type with one-year and five-year survival rates of less than 20% and 10% respectively. This project seeks to explore the potential for Krüppel-like factor 5 (KLF5) to be a novel therapeutic target in PDAC. The proposed research leverages three key discoveries. First, high-throughput genetic screening has revealed that PDAC human cancer cells are selectively sensitive to KLF5 inactivation. Second, KLF5 expression is low in normal pancreas tissue, but KLF5 is upregulated during pancreatitis and supports the proto-oncogenic function of Kras in this context. Third, mouse genetic studies indicate that normal intestinal stem-cell self-renewal continues in the absence of Klf5. These data together suggest KLF5 has a wide therapeutic index in PDAC. However, KLF5 is a difficult target for classical drug discovery approaches, largely due to our limited understanding of protein-protein interactions which support KLF5 function. This project will address two major gaps in our understanding of KLF5 in PDAC. It will evaluate whether targeting KLF5 interactions disrupts KLF5 function, and it will explore how KLF5 contributes to proto- oncogenesis of PDAC precursor cells. An integrated high-throughput reporter screen and mass spectrometry analysis has illustrated that several KLF5 coactivators also bind KLF5. These coactivators will be deeply investigated to reveal the mechanisms of their interactions with KLF5. This investigation will highlight whether KLF5-coactivator interactions are critical both for KLF5 transcriptional activity and for PDAC cell fitness (Aim 1). The overall goal of this aim is to understand if these interactions can be exploited to acutely target KLF5 activity in PDAC. This will inform the potential for the advancement of KLF5 as a targeted therapy. In addition, pancreatitis promotes an aberrant proto-oncogenic epigenetic landscape, and also leads to Klf5 upregulation. Using a transgenic mouse model, the function of Klf5 in normal and inflamed pancreatic tissue will be interrogated. Specifically, this investigation will determine if Klf5 supports the aberrant epigenic profile induced by pancreatitis (Aim 2). The overall goal of this aim will be to determine if Klf5 has an active role in shaping the genome of PDAC progenitor cells. This might explain why PDAC is selectively sensitive to KLF5 deletion, while KLF5 is entirely dispensable in normal pancreatic homeostasis. The required skills and knowledge to carry out these two aims will be supported by sponsor Dr. Chris Vakoc and co-sponsor Dr. David Tuveson, in addition to the Cold Spring Harbor Laboratory School of Biological Sciences. The mentorship and environment at Cold Spring Harbor Laboratory will provide all of the necessary resources for a tailored training program to effectively develop the applicant into an independent experimentalist, analyst, and communicator of gene regulation biology and cancer ...