Metabolic reprogramming by mutant GNAS creates an actionable dependency in intraductal papillary mucinous neoplasms of the pancreas

Abstract

BackgroundOncogenic ‘hotspot’ mutations ofKRASandGNASare two major driver alterations in intraductal papillary mucinous neoplasms (IPMNs), which arebona fideprecursors to pancreatic ductal adenocarcinoma. We previously reported that pancreas-specificKrasG12DandGnasR201Cco-expression in p48Cre; KrasLSL-G12D; Rosa26LSL-rtTA; Tg (TetO-GnasR201C) mice (‘Kras;Gnas’ mice) caused development of cystic lesions recapitulating IPMNs.ObjectiveWe aim to unveil the consequences of mutantGnasR201Cexpression on phenotype, transcriptomic profile and genomic dependencies.DesignWe performed multimodal transcriptional profiling (bulk RNA sequencing, single-cell RNA sequencing and spatial transcriptomics) in the‘Kras;Gnas’ autochthonous model and tumour-derived cell lines (Kras;Gnascells), whereGnasR201Cexpression is inducible. A genome-wide CRISPR/Cas9 screen was conducted to identify potential vulnerabilities inKrasG12D;GnasR201Cco-expressing cells.ResultsInduction ofGnasR201C—and resulting G(s)alpha signalling—leads to the emergence of a gene signature of gastric (pyloric type) metaplasia in pancreatic neoplastic epithelial cells. CRISPR screening identified the synthetic essentiality of glycolysis-related genesGpi1andSlc2a1inKrasG12D;GnasR201Cco-expressing cells. Real-time metabolic analyses inKras;Gnascells and autochthonousKras;Gnasmodel confirmed enhanced glycolysis onGnasR201Cinduction. Induction ofGnasR201CmadeKrasG12Dexpressing cells more dependent on glycolysis for their survival. Protein kinase A-dependent phosphorylation of the glycolytic intermediate enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) was a driver of increased glycolysis onGnasR201Cinduction.ConclusionMultiple orthogonal approaches demonstrate thatKrasG12DandGnasR201Cco-expression results in a gene signature of gastric pyloric metaplasia and glycolytic dependency during IPMN pathogenesis. The observed metabolic reprogramming may provide a potential target for therapeutics and interception of IPMNs.