title: PO-48 - Assessment of the procoagulant potential state of tumour-MP in cancer patients.
abstract: BACKGROUND
  The venous thromboembolism is considered one of the highest risk factor in cancer patients for instance ovarian and pancreas. This hypercoagulability state is believed to be caused by tumour cells that can produce a variety of procaogulant factors including tissue factor (TF) bearing microparticles (MP). Chemotherapy is an independent risk factor for venous thromboembolism (VTE) in patients and it can leads to coagulation activation and may increase microparticles that can increase risk of thrombosis.
  
  
  OBJECTIVE
  Therefore, our current hypothesis is that this increased risk of VTE is due to release of tumour MP into the blood. To further investigate this mechanism an ex-vivo microfluidic model system was developed wherein tumour spheroids were grown and transferred onto a microfluidic chip and assessed, under flow conditions, for procoagulant activity (PCA).
  
  
  METHODS
  Tumour spheroids from pancreatic cancer cell line AsPC1 and human glioblastoma cell line U87 were generated using the liquid overlay method in a 96-well plate, then transferred to a microfluidic chip, designed with a trap within the device to immobilise the spheroid. The procoagulant potential of cell-free supernatant was measured using a prothrombin time clotting assay. Procoagulant activity was assessed under flow rate of 3.0 μL min-1 for 6 hours.
  
  
  RESULTS
  Several tumour cell lines (A2780, SKOV3, MIA Paca2, AsPC1 and U87) were assessed for PCA of media (MP associated) and then subsequently assessed for spheroid formation. Prothrombin time of cell-free media was A2780: 794s, SKOV3: 203.4s, MIA Paca2: 412s, AsPC1: 69s and U87: 50.3s. The pancreatic cell line AsPC-1 and glioblastoma cell line U87 were selected for further study on the basis of relatively high PCA and ability to form stable spheroids. When transferred to a microfluidic chip, AsPC1 tumour spheroids showed a slowing of PCA of media over a 6-hour period from 36.6 to 309s. U87 tumour spheroids showed a reduction in PCA of media over a 6-hour period from 51.3 to 108.9s.
  
  
  CONCLUSIONS
  This is the first report of tumour spheroids maintained in a microfluidic device and then subsequently assessed for PCA. Tumour spheroids of AsPC1 were shown to produce continuous procaogulant activity and this is presumably due to tumour microparticle release. This new model system offers a way to assess tumour associated PCA under flow conditions.
authors.affiliation: School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Algarni
authors.affiliation: School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Greenman
authors.affiliation: School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, United Kingdom.
authors.forename: L A
authors.initials: LA
authors.lastname: Madden