Vladan Čokić, Olivera Mitrović Ajtić, Dragoslava Đikić, Teodora Dragojević, Tijana Subotički, Milica Vukotić

Institute for Medical Research, National Institute for Medical Research, University of Belgrade

In order to discover the mechanism underlying frequent thrombosis in hematologic malignancies, it will be initiated the inflammation dependent activation and interplay of endothelial cells, platelets, and leukocytes with subsequent formation of microparticles and nitric oxide (NO) linked to thrombus generation by induction of coagulation and fibrinolysis. Cancer-associated thrombosis (CAT) is the second leading cause of death in cancer patients including both venous and arterial thromboembolism. While CAT can be treated with anticoagulants, benefits of therapy must be balanced with the increased bleeding risks. The coagulation related cells and biomarkers will be analyzed and selected by flow cytometry from the following hematologic malignancies: multiple myeloma, lymphoma, acute myeloid leukemia, and transplanted patients with graft-versus-host disease (GvHD). Besides clinical follow-up of the patients, extensive preclinical studies will be performed using in vitro cell cultures (hypoxia chamber, RT-qPCR, immunoassays), in vivo mouse models (NO analyzer), and in silico profiling. Activation of the coagulation factors will be observed through the prothrombotic properties of endothelium (microchip flow-chamber system), neutrophil extracellular traps (NETs, spectrophotometry) and anticancer treatments. The proposed study will show inflammatory stimulation of hypercoagulability, chemotaxis of immune response, and NET formation as well as modulation of fibrinolytic system and miRNA regulated platelet activation. In addition, the equilibrium between NO production and oxygen tension will largely influence the inflammation-dependent thrombus formation, with a prognostic significance of hypoxia related gene signature. Understanding the principal mechanisms may allow the development of new therapies to safely prevent CAT in the hematologic malignancies and GvHD, while determination of the specific biomarkers in each malignancy can be used as predictors of thrombosis.