Poster Presentation 32nd Lorne Cancer 2020

Seeing is believing: Mapping and targeting the extracellular matrix in human pancreatic ductal adenocarcinoma (#328)

Brooke Pereira 1 2 , Shona Ritchie 1 2 , David Herrmann 1 2 , Max Nobis 1 2 , Kendelle Murphy 1 2 , Romain Rouet 1 2 , Xanthe Metcalf 1 2 , Daniel Reed 1 2 , Cecilia Chambers 1 2 , Lea Abdulkhalek 1 2 , Janett Stoehr 1 2 , Joanna Skhinas 1 2 , Tatjana Schmitz 1 2 , Amber Johns 1 2 , Angela Murphy 1 2 , Mehreen Ashri 1 2 , Lorraine Chantrill 1 3 , Jeff Evans 4 5 , Benjamin Parker 6 , Gus Grey 7 , Jennifer Morton 4 5 , Marina Pajic 1 2 , Anthony Gill 1 8 9 10 , Jaswinder Samra 11 , Thomas Cox 1 2 , Paul Timpson 1 2
  1. Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
  2. St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
  3. St Vincent’s Hospital, Sydney, NSW, Australia
  4. Beatson Institute, Cancer Research UK , Glasgow, Scotland, United Kingdom
  5. Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
  6. The University of Melbourne, Melbourne, VIC, Australia
  7. Department of Physiology, The University of Auckland, Auckland, New Zealand
  8. The University of Sydney, Sydney, NSW, Australia
  9. Kolling Institute of Medical Research, Sydney, NSW, Australia
  10. NSW Health Pathology, Department of Anatomical Pathology, Royal North Shore Hospital, St. Leonards, NSW, Australia
  11. Department of Surgery, Royal North Shore Hospital, St. Leonards, NSW, Australia

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, with a five-year survival rate of only 9%. PDAC is characterised by robust stromal activation, leading to extensive desmoplasia. Stromal and matrisomal changes are widespread, where extracellular matrix (ECM) proteins are not only aberrantly expressed and degraded, but also shift in terms of spatial organisation, biomechanics and topography. Recently, we have shown that targeting desmoplastic stroma can improve standard-of-care chemotherapy efficacy and impairs metastasis in mouse models of PDAC. As such, we have embarked on a new project using quantitative proteomics and advanced microscopy to unravel the matrisomal signatures of patient-derived tumours and matched non-malignant specimens to find new desmoplasia targets in PDAC. In parallel, we are building a biobank of clinically relevant and diverse patient-derived xenografts (PDXs), which we will use to interrogate future ECM targets.

To date, 16 fresh human specimen sets (PDAC tumour, non-malignant pancreas, PDAC/non-malignant interface, and duodenum) have been collected from Whipple’s procedures at Royal North Shore Hospital. For proteomic analysis, patient-matched tumour and non-malignant specimens are enriched for matrisomal components using IsDOT (In Situ Decellularisation of Tissues) methodology. Specimens are also cryopreserved and formalin-fixed & paraffin embedded (FFPE) for future genomic sequencing and histopathology, respectively. The ECM structure and organisation of decellularised and FFPE specimens are analysed using multiphoton microscopy (Second Harmonic Generation imaging (SHG)), lightsheet microscopy and polarised light imaging (Picrosirius Red and collagen birefringence). For xenografting, fresh tumour chunks are grafted orthotopically and/or subcutaneously in immunocompromised host mice. Future work includes analysing the interface between malignant and non-malignant tissue with MALDI-Mass Spectrometry imaging (MALDI-MSI) proteomics to spatially chart ECM proteins in specific zones of the tumour. Overall, characterising and mapping the matrisome of pancreatic tumours will uncover novel and specific therapeutic targets, presenting an opportunity to markedly improve the poor outcomes currently observed in PDAC patients.