Objective:To ivestigate the possible effects on normal bone marrow derived mesenchymal stem cells(MSCs) when co-cultured with myeloma cell line U266. Methods:Bone marrow MSCs from normal subjects were co-cultured with U266 by transwell. On the given time point, the levels of TNF-α in the medium, the mRNA expression levels of Dickkopf 1(DKK1) and hepatocyte growth factor(HGF) were mesured. Results:No evident morphologic and proliferative alterations could be observed in bone marrow derived MSCs after co-cultured with U266, and there was also no detectable increase in the level of TNF-α in superant of the co-culture system. However, the mRNA expression levels of DKK1 and HGF were upregulated in bone marrow MSCs after 5 days’ co-culture with U266. Conlusion:The “cross-talk” between bone marrow MSCs and U266 induced dysregulation of DKK1 and HGF, which might be involved in the pathogenesis of multiple myeloma.