Multiple myeloma (MM) always presents osteolytic bone lesions, resulting from the abnormal osteoblastic and osteoclastic function in patients. MM patients exhibit the impairment of osteogenic differentiation of BMMSCs (bone marrow mesenchymal stem cells) and osteoblast deficiency. Effects of the drug, lenalidomide on the osteoblastic functions and the involved mechanisms remain unexplored. In the present study, it is observed that the osteogenic differentiation of BMMSCs from MM patients (MM-MSCs) is impaired and activation of Notch signaling pathway in MM-MSCs is abnormal. Notch signaling activation inhibits BMMSCs osteogenesis. Knockdown of Notch1 expression and DAPT application reverse the osteogenic differentiation from MM-MSCs. Furthermore, it is shown that the gene expression of Notch signaling molecules, including receptors, ligands and downstream factors are significantly decreased in MM-MSCs following lenalidomide treatment, compared with non-treated MM-MSCs. Taken together, treatment with lenalidomide restores the osteogenic differentiation of MM-MSCs via deactivating Notch signaling pathway.
Keywords: Notch signaling; lenalidomide; mesenchymal stem cells; multiple myeloma; osteogenic differentiation.