miRNA-202 in bone marrow stromal cells affects the growth and adhesion of multiple myeloma cells by regulating B cell-activating factor

Bone marrow stromal cells (BMSCs) up-regulate B cell-activating factor (BAFF) in multiple myeloma. Increasing experimental evidence has shown that microRNAs play a causal role in hematology tumorigenesis. In this study, we characterized the role of miR-202 in regulating the expression of BAFF in BMSCs. It was found that expressions of BAFF mRNA and protein were increased in BMSCs treated with miR-202 inhibitor. The growth rate of miR-202 mimics transfection cells was significantly lower than that of non-transfected cells. The expression of Bcl-2 protein was down-regulated, and Bax protein was up-regulated after miR-202 mimics transfection. Over-expression of miR-202 in BMSCs rendered MM cells more sensitive to bortezomib. More significantly, the regulatory effect of miR-202 could inhibit the activation of NF-kappa B pathway in BMSCs. These results suggest that miR-202 functions as a modulator that can negatively regulate BAFF by inhibiting MM cell survival, growth, and adhesion in the bone marrow microenvironment.