Expression data from exosomes

Bone marrow (BM) niches provide an optimal substrate for multiple myeloma (MM) cell lodgement and growth. Nevertheless, little is known about the putative mechanisms by which the BM microenvironment can lead to initiation or progression of oncogenesis in this disease. We have demonstrated that BM mesenchymal stromal cell-derived exosomes transfer their miRNA and protein content to clonal plasma cells, thus acting as synaptic vesicles responsible for molding the microenvironment surrounding multiple myeloma (MM) cells, leading to MM growth, dissemination and, therefore, disease progression. We used microarray to detail the changes in microRNA expression in MM-BM mesenchymal stromal cell (MSC)-derived exosomes, compared to normal- and monoclonal gammopathy of undetermined significance- BM-MSC-derived exosomes. Exosomes have been isolated from cell culture supernatant of BM-MSCs (MM=7; MGUS=2; Normal=4), and subsequently evaluated at ultrastructural level by using electron microscopy and immunogolf labeling. RNA was extracted; and miRNA profiling has been assessed by using TaqMan human miRNA profiling. Mean miRNA expression value has been used for miRNA RT-qPCR data normalization, as described (Mestdagh et al., 2009).