Oral Presentation Australasian Extracellular Vesicles Conference 2020

Investigating the Effects of Platelets, Platelet Extracellular Vesicles and Aspirin on Colorectal Cancer (#8)

David Capraro 1 2 , David Connor 1 2 , Joanne Joseph 1 2 3
  1. Blood, Stem Cell and Cancer Research Program, St Vincent's Centre for Applied Medical Research, Sydney, NSW, Australia
  2. St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
  3. Department of Haematology, St Vincent's Hospital, Sydney, NSW, Australia

It is well recognised that there is significant cross-talk between platelets and cancer cells. Platelets and platelet-derived extracellular vesicles (PEVs) are considered to play a role in cancer progression and metastasis; cancer cells secrete products that can result in platelet activation and lead to thrombus formation. Aspirin, the most commonly used antiplatelet agent, may have a beneficial effect in some cancer types, and has been shown to reduce the risk of developing colorectal cancer (CRC) or metastasis in patients with known CRC. Our work examines the interaction between platelets, PEVs and CRC and the potential effects of aspirin.

Washed platelets and PEVs generated from agonist stimulated samples obtained from healthy controls were co-incubated with HCT15 and HCT116 CRC cell lines for a period of 24 hours. Using immunofluorescence microscopy, we observed specific binding of both platelets and PEVs to CRC. Co-incubation of CRC cells with platelets in whole blood from healthy controls resulted in increased expression of platelet activation markers (CD62p, CD63 and PAC-1) in a dose dependent manner. Washed platelets and PEVs generated from agonist stimulated samples obtained from health controls resulted in increased migration and invasion of HCT116 CRC cells in a Transwell assay, with platelets having the greatest effect. We aim to perform future experiments using platelets and PEVs obtained from patients with CRC to determine any differences from healthy controls and will also examine the effects of aspirin.