Metabolic reprogramming by mutant GNAS creates an actionable dependency in intraductal papillary mucinous neoplasms of the pancreas.
Abstract
Oncogenic 'hotspot' mutations of <i>KRAS</i> and <i>GNAS</i> are two major driver alterations in intraductal papillary mucinous neoplasms (IPMNs), which are <i>bona fide</i> precursors to pancreatic ductal adenocarcinoma. We previously reported that pancreas-specific <i>Kras</i> <sup>G12D</sup> and <i>Gnas</i> <sup>R201C</sup> co-expression in p48<sup>Cre</sup>; Kras<sup>LSL-G12D</sup>; Rosa26<sup>LSL-rtTA</sup>; Tg (TetO-Gnas<sup>R201C</sup>) mice (<i>'Kras;Gnas</i>' mice) caused development of cystic lesions recapitulating IPMNs.
We aim to unveil the consequences of mutant <i>Gnas</i> <sup>R201C</sup> expression on phenotype, transcriptomic profile and genomic dependencies.
We performed multimodal transcriptional profiling (bulk RNA sequencing, single-cell RNA sequencing and spatial transcriptomics) in the <i>'Kras;Gnas</i>' autochthonous model and tumour-derived cell lines (<i>Kras;Gnas</i> cells), where <i>Gnas</i> <sup>R201C</sup> expression is inducible. A genome-wide CRISPR/<i>Cas</i>9 screen was conducted to identify potential vulnerabilities in <i>Kras<sup>G12D</sup>;Gnas<sup>R201C</sup></i> co-expressing cells.
Induction of <i>Gnas</i> <sup>R201C</sup>-and resulting G<sub>(s)</sub>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 genes <i>Gpi1</i> and <i>Slc2a1</i> in <i>Kras</i> <sup>G12D</sup>;<i>Gnas</i> <sup>R201C</sup> co-expressing cells. Real-time metabolic analyses in <i>Kras;Gnas</i> cells and autochthonous <i>Kras;Gnas</i> model confirmed enhanced glycolysis on <i>Gnas</i> <sup>R201C</sup> induction. Induction of <i>Gnas</i> <sup>R201C</sup> made <i>Kras</i> <sup>G12D</sup> expressing 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 on <i>Gnas</i> <sup>R201C</sup> induction.
Multiple orthogonal approaches demonstrate that <i>Kras</i> <sup>G12D</sup> and <i>Gnas</i> <sup>R201C</sup> 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.
EDRN PI Authors
Medline Author List
- Abou-Elkacem L
- Bhattacharya P
- Chellakkan Selvanesan B
- Date K
- Dede M
- Dutta P
- Enriquez J
- Hart T
- Kim M
- Maitra A
- Makino Y
- Min J
- Okumura T
- Rajapakshe KI
- Sagara A
- Sans M
- Siemann MJ
- Smith P
- Thege FI
- Yee N
PubMed ID
Sources
- Cancer Data Expo