Flash Talk & E-Poster - Virtual Presentation 33rd Lorne Cancer Conference 2021

Utilising murine pancreatic cancer organoids to understand epithelial-mesenchymal transition in cancer (#51)

Ronnie Ren Jie Low 1 2 3 4 , Ka Yee Fung 1 2 , Adele Preaudet 1 , Gemma van Duijneveldt 1 2 , Frederic Hollande 3 4 , Sean M. Grimmond 3 4 , Tracy Putoczki 1 2
  1. The Walter and Eliza Hall of Medical Research, Parkville, VIC, Australia
  2. Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
  3. University of Melbourne Centre for Cancer Research, University of Melbourne, Parkville, VIC, Australia
  4. Department of Clinical Pathology, University of Melbourne, Parkville, VIC, Australia

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers of all solid malignancies. Most patients succumb to the disease within 6 months, with the average 5-year survival of 9%. Epithelial-mesenchymal transition (EMT) is strongly implicated in tumour cell invasion, metastasis and drug resistance. There is an urgent need to better understand the progression of pancreatic cancer, including the role of EMT, so that novel treatment options can be identified.

METHODS: A pipeline has been optimised for the growth of murine organoids. YFP+ ductal epithelial cells were isolated from the pancreata of PdxCre; RosaYFP mice to generate normal pancreatic organoids, whereas tumour organoids were generated from YFP+ cells isolated from the primary tumours and matched metastases (liver, peritoneum or lung) of the PdxCre; KrasG12V; p53R172H; RosaYFP mouse model of PDAC.  Immunofluorescent staining for Epcam was performed on the primary tumour to further divide the YFP+ tumour population into cells in epithelial state (Epcam positive) and tumour epithelial cells that underwent EMT (Epcam negative). The EMT states of the organoids were further studied using quantitative polymerase chain reaction, western blot, immunohistochemistry and allograft generation to determine if the EMT state is retained in the organoid ex vivo.

RESULTS: There were 100% success rate of both normal and tumour organoid generation resulting in a biobank of 5 normal ductal organoids, 9 primary tumour organoids and 8 metastatic organoids. Epithelial state and EMT state organoids were successfully generated from all 9 primary tumours. The molecular and histological analyses confirmed that the organoids retain the characteristics ex vivo.

CONCLUSION: We have established a complementary suite of pre-clinical model systems that accurately recapitulate the histopathological and molecular features of PDAC. These model systems will provide platform tools for characterisation of the behaviour of epithelial cells that will assist us in better understanding PDAC progression. Ultimately, this will guide the discovery of new therapeutic opportunities.