Involvement of Extracellular Vesicles (EVs) in Hematologic Disorders.

Inherited and acquired defects as well as exposure to chemotherapy, radiation, and cytokines result in release of EVs from a variety of cells (e.g. hematopoietic stem and progenitor cells, blood, vascular, and tumor cells) to the bone marrow microenvironment, the vascular compartment, and the target organ with auto- and paracrine effects. Extracellular vesicles, which include microparticles and exosomes, express adhesion molecules, cytokines, growth versus apoptotic factors, coagulation factors and miRNA. In hematologic malignancies, EVs promote metastasis, angiogenesis, and thrombogenicity. In thalassemia/sickle cell diseases, EVs promote cell injury, apoptosis, and thrombogenicity.