ABSTRACT
Objective Oncogenic “hotspot” mutations of KRAS and GNAS are two major driver alterations in Intraductal Papillary Mucinous Neoplasms (IPMNs), which are bona fide precursors to pancreatic ductal adenocarcinoma. We previously reported that pancreas-specific KrasG12D and GnasR201C co-expression in p48Cre; KrasLSL-G12D; Rosa26LSL-rtTA; Tg (TetO-GnasR201C) mice (“Kras;Gnas” mice) caused development of cystic lesions recapitulating IPMNs. Here, we aim to unveil the consequences of mutant GnasR201C expression on phenotype, transcriptomic profile, and genomic dependencies.
Design We performed multimodal transcriptional profiling (bulk RNA sequencing, single cell RNA sequencing, and spatial transcriptomics) in the “Kras;Gnas” autochthonous model and tumor-derived cell lines (Kras;Gnas cells), where GnasR201C expression is inducible. A genome-wide CRISPR/Cas9 screen was conducted to identify potential vulnerabilities in KrasG12D;GnasR201Cco-expressing cells.
Results Induction of GnasR201C – and resulting G(s)alpha signaling – 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 genes Gpi1 and Slc2a1 in KrasG12D;GnasR201C co-expressing cells. Real-time metabolic analyses in Kras;Gnas cells and autochthonous Kras;Gnas model confirmed enhanced glycolysis upon GnasR201C induction. Induction of GnasR201C made KrasG12D expressing cells more dependent on glycolysis for their survival. Protein kinase A-dependent phosphorylation of the glycolytic intermediate enzyme PFKFB3 was a driver of increased glycolysis upon GnasR201C induction.
Conclusion Multiple orthogonal approaches demonstrate that KrasG12D and GnasR201C co-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.
What is already known on this topic
Activating “hotspot” mutations of KRAS and GNAS are found in a majority of Intraductal Papillary Mucinous Neoplasms (IPMNs).
Expression of mutant KRAS and GNAS drives development of IPMN-like cystic lesions in the murine pancreas that eventually progress to pancreatic ductal adenocarcinoma (PDAC).
What this study adds
Mutant GNAS and the resulting aberrant G(s)alpha signaling drives a transcriptional signature of gastric (pyloric type) metaplasia in IPMNs with mucin production.
Aberrant G(s)alpha signaling enhances glycolysis via protein kinase A-dependent phosphorylation of the glycolytic enzyme PFKFB3.
Enhanced glycolysis in KRAS;GNAS-mutated IPMN cells is validated via multiple orthogonal approaches in vitro and in vivo and represents an actionable metabolic vulnerability.
How this study might affect research, practice or policy
The present study provides mechanistic insight into how aberrant G(s)alpha signaling alters the biology of Kras-mutant pancreatic epithelial neoplasia through metaplastic and metabolic reprogramming.
Targeting glycolysis in IPMNs may represent both a therapeutic avenue as well as an opportunity for intercepting progression to invasive cancer.
Competing Interest Statement
A. M. is listed as an inventor on a patent that has been licensed by Johns Hopkins University to Thrive Earlier Detection. A.M. serves as a consultant for Tezcat Biosciences.
Footnotes
Funding: A.M. is supported by the MD Anderson Pancreatic Cancer Moon Shot Program, the Khalifa Bin Zayed Al-Nahyan Foundation, and the NIH (U01CA200468, U54CA274371, and P50CA221707). F.I.T., is supported by the Ben and Rose Cole Charitable PRIA Foundation. Y.M. is supported by a Japan Society for the Promotion of Science (JSPS) Overseas Research Fellowship.
Conflict of Interest: A.M. is listed as an inventor on a patent that has been licensed by Johns Hopkins University to Thrive Earlier Detection. A.M. serves as a consultant for Tezcat Biosciences.