Extracellular vesicles of bone marrow stromal cells rescue chronic lymphocytic leukemia B cells from apoptosis, enhance their migration and induce gene expression modifications
EHA Learning Center. Crompot E. Sep 1, 2017; 196260
Topic: 3F Pediatric lymphoid malignancies
Ms. Emerence Crompot
Ms. Emerence Crompot
Login now to access Regular content available to all registered users.

Access to EHA Members only content is an EHA membership benefit.
Click here to join EHA or renew your membership here.


Journal Abstract
Discussion Forum (0)
Rate & Comment (0)

Co-Authors: Michael Van Damme, Karlien Pieters, Marjorie Vermeersch, David Perez-Morga, Philippe Mineur, Marie Maerevoet, Nathalie Meuleman, Dominique Bron, Laurence Lagneaux, Basile Stamatopoulos

Abstract: Interactions between chronic lymphocytic leukemia (CLL) B cells and the bone marrow (BM) microenvironment play a major function in the physiopathology of CLL. Extracellular vesicles (EVs), which are composed of exosomes and microparticles, play an important role in cell communication. However, little is known about their role in CLL / microenvironment interactions. In the present study, EVs purified by ultracentrifugation from BM mesenchymal stromal cell (BM-MSC) cultures were added to CLL B cells. After their integration into CLL B cells, we observed a decrease of leukemic cell spontaneous apoptosis and an increase in their chemoresistance to several drugs, including fludarabine, ibrutinib, idelalisib and venetoclax after 24 hours. Spontaneous (P=0.0078) and stromal cell-derived factor 1α -induced migration capacities of CLL B cells were also enhanced (P=0.0020). A microarray study highlighted 805 differentially expressed genes between leukemic cells cultured with or without EVs. Of these, genes involved in the B-cell receptor pathway such as CCL3/4, EGR1/2/3, and MYC were increased. Interestingly, this signature presents important overlaps with other microenvironment stimuli such as B-cell receptor stimulation, CLL/nurse-like cells co-culture or those provided by a lymph node microenvironment. Finally, we showed that EVs from MSCs of leukemic patients also rescue leukemic cells from spontaneous or drug-induced apoptosis. However, they induce a higher migration and also a stronger gene modification compared to EVs of healthy MSCs. In conclusion, we show that EVs play a crucial role in CLL B cells/BM microenvironment communication.

Article Number: 1594

Doi: 10.3324/haematol.2016.163337

Code of conduct/disclaimer available in General Terms & Conditions