Expression data from bone marrow mesenchymal stromal cells obtained from healthy donors and myeloma patients

Multiple myeloma (MM) is a B-cell neoplasm characterized by clonal expansion of malignant plasma cells (MM cells) in the bone marrow (BM) compartment, where they acquire resistance to chemotherapy-mediated apoptosis. Natural history of patients include a premalignant stage, the MM diagnosis, the treatment, the remission, and for most of them the relapse. BM mesenchymal stromal cells (MSC) from newly diagnosed MM patients are functionally different from healthy donors (HD) MSC and display a distinct transcriptome. They have been largely involved in MM pathogenesis and chemoresistance acquisition. In order to determine if MM-MSC also participate to relapse, we focused on the characterization of MSC from patients with MM at different stages of the disease. We obtained patient MSC’s samples at diagnosis, at 2 years after intensive treatment without relapse and at the relapse from an intensive treatment. We used MCS from HD as control. All MSC were able to support MM cells growth through released factors, and still multipotent since able to differentiate into osteoblast and adipocyte. A transcriptomic analysis between these groups reveals differences in gene expression between HD and MM MSC whatever stage of the disease, suggesting that the difference in gene expression in MM-MSC persist with time. These data demonstrate an imprinting of MSC as soon as they were in contact with MM cells, which persist even after the disappearance of MM cells. This imprinting is in favour of an easier differentiation towards adipogenesis. Mesenchymal stromal cells (MSC) from bone marrow (BM) were selected at successive stages of multiple myeloma (MM) and in healthy donor (HD) for RNA extraction and hybridization on Affymetrix microarrays. We sought to compare expression profiles of MM vs HD BM MSC. To that end, we selected patients according to SliM CRAB and International Myeloma Working Group uniform response criteria: at diagnosis (D), at early relapse from an intensive treatment (<18 months) (ER), and in persistent complete response (CR) at least 2 years after an intensive treatment.