Abstract PR-09: Temporally resolved proteomics identifies nidogen-2 as a co-target in pancreatic cancer that modulates fibrosis and therapy response

Abstract Pancreatic cancer (PC) is highly lethal, with a five-year survival rate of ∼13%. PC is characterised by progressive cancer-associated fibrosis. We and others have shown that targeting cancer fibrosis can improve chemotherapy efficacy and impair metastasis in pre-clinical models. As such, we aimed to use integrated temporal proteomics to dissect the matrix signatures of pancreatic tumours from the highly-metastatic KPC (Pdx1-Cre; LSL-K-rasG12D/+; LSL-p53R172H/+) and poorly-metastatic KPflC (Pdx1-Cre; LSL-K-rasG12D/+; LSL-p53fl/+) mouse models, with an aim to identify new metastatic drivers in this deadly disease. We collected pancreatic tissue from KPflC, KPC and wildtype (WT) controls at early (∼50 days), mid (∼90 days) and late-stage disease (∼200 days), enriched them for matrix proteins using ISDoT de-cellularisation and analysed them using data independent acquisition liquid chromatography-tandem mass spectrometry (DIA LC-MS/MS). DIA LC-MS/MS revealed an increased abundance of Nidogen-2 (NID2) in KPC tumours compared to KPflC. Organotypic matrices generated with NID2 CRISPR-interference (CRISPRi) CAFs had reduced fibrosis, shown via second harmonic generation (SHG) multiphoton imaging and Picrosirius Red/birefringence analysis. Organotypic invasion assays revealed that depletion of CAF NID2 significantly impeded the 3D invasion of cancer cells. Subcutaneous and orthotopic co-seeding experiments using NID2 CRISPRi CAFs with cancer cells showed that NID2 inhibition significantly impeded tumour growth and fibrosis. Intravital (in vivo) imaging with quantum dots revealed improved vascular patency in live NID2 targeted tumours, with improved response to chemotherapy. Strikingly, in orthotopic models, mice bearing NID2 targeting had significantly reduced liver metastasis and increased survival, revealing NID2 as a new stromal co-target in this aggressive disease. Citation Format: Paul Timpson, Brooke Pereira, Shona Ritchie, katie Gordon, Thomas Cox. Temporally resolved proteomics identifies nidogen-2 as a co-target in pancreatic cancer that modulates fibrosis and therapy response [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr PR-09.