Background: Endothelium activation is essential in pathogenesis of cancer associated thrombosis (CAT). Endothelial cell (EC) is a potential target of cancer cell derived microparticles (CaCe-dMPs). We recently showed that EC exposed to CaCe-dMPs acquire a procoagulant phenotype characterized by an enhancement of thrombin generation (TG) transferable to daughter cells.

Aims: We investigated the implication of tissue factor (TF) in the new procoagulant profile acquired by EC exposed to CaCe-dMPs and if TF alone is capable of inducing this change.

Methods: Microparticles released in conditioned medium from pancreas adenocarcinoma cells (BXPC3) were isolated with differential centrifugation. Human umbilical vein endothelial cells (HUVEC) were cultured for 72h according to 5 experimental conditions: in presence of (a) BXPC3-dMPs (b) BXPC3 conditioned medium depleted in MPs (c) MP-Reagent (no TF and 4uM of phospholipids) (d) PPP-Reagent High (5pM TF; 4uM phospholipids) (e) PPP-Reagent Low (1pM TF; 4uM phospholipids) or (f) Dade Innovin (5nM TF, phospholipids, calcium). Capacity of exposed-EC to enhance TG in PPP was assessed with CAT assay (Thrombinoscope, Diagnostica Stago, France). TF concentration was determined by using the Zymutest Tissue Factor kit (Hyphen, France).

Results: Thrombogram parameters in normal PPP of HUVEC cells exposed or not (control) to respectively BXPC3 derived vesicles (BXPC3-dEVs), BXPC3 conditioned medium depleted in vesicles (BXPC3-MC), human recombinant TF Dade Innovin (5nM TF, phospholipids and calcium), PPPReagent High (5pM TF and 4μM phospholipids), PPP-Reagent Low (1pM TF and 4μM phospholipids) or MP-Reagent (no TF and 4μM of phospholipids). Values are mean  sd of 3 experiments
HUVEC exposed to BXPC3-dMPs acquired a procoagulant profile with a significant enhancement of TG as compared to control experiment (non-exposed HUVEC). However, HUVEC exposed to BXPC3 conditioned medium, Innovin, MP-R, PPP-R high or low are not capable to enhance TG and display thrombogram parameters similar to the control (Table I). Furthermore, only HUVEC exposed to BXPC3-dMPs display a high amount of TF (563,84 ± 47,47 pg/ml) (Table II).

Conclusions: According to the histological type of cancer, CaCe-dMPs induce a procoagulant shift of EC that present high TF activity. However, exposition to soluble TF and thus, also with high concentration, can’t induce this procoagulant shift. Indeed, only TF+ MPs can induce this change and represent a potent activator of EC.

« Back to ISTH 2021 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/role-of-tissue-factor-in-the-procoagulant-shift-of-endothelial-cells-upon-exposure-to-cancer-cell-derived-microparticles/