NFAT Mediates Pro-Tumorigenic Inflammation in Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma [mouse multiome]

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stroma, low immunogenicity, and resistance to therapy. Cancer-associated fibroblasts (CAFs) are key stromal cells within the tumor microenvironment (TME) that drive tumor progression. Interleukin-1 (IL-1) promotes fibrosis, pathogenic inflammation, and poor prognosis in PDAC. Using a novel single-cell multiomic approach, we investigate the IL-1 signaling axis in human and mouse models of PDAC, identifying nuclear factor of activated T cells (NFAT) transcription factors as key mediators. IL1R1+ CAFs activate an inflammatory phenotype associated with elevated NFAT motif activity and gene expression. In vivo, NFAT inhibition in a mouse model of PDAC significantly reduces tumor weight and fibrosis, supporting its pro-tumorigenic role. Our findings suggest that NFAT mediates IL-1-induced inflammation in PDAC, highlighting its potential as a therapeutic target. This study demonstrates the power of multiomic analyses to uncover therapeutic targets within the complex tumor microenvironment. Overall design: To study IL-1 signaling in a mouse model of PDAC, we developed an orthotopic allograft model via pancreatic inoculation of KPC cells following suture ligation at the mid-pancreas. The suture ligation occludes the pancreatic duct and induces pancreatitis, which helps generate an inflammatory response conducive to PDAC induction while preserving adequate blood supply to the distal pancreas via the short gastric and left gastroepiploic vessels. To model IL-1 signaling inhibition, we chose AF12198, a small peptide antagonist of IL1R1. To counteract any potential immunosuppressive effects of IL-1 inhibition and enhance antitumor immunity, we included IL-12, a potent immune activator. We injected KPC cells into the suture-ligated pancreas, waited for 2 weeks to ensure tumor induction, then performed intratumoral injection with saline, AF12198, IL-12, or a combination of AF12198 plus IL-12. Tissues were harvested and analyzed 2 weeks following intratumoral injection