Matrix metalloproteinases-1 and -2, and tissue inhibitor of metalloproteinase-2 production is abnormal in bone marrow stromal cells of multiple myeloma patients

We have investigated the production of metalloproteinases (MMP-1, MMP-2, MMP-9) and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in bone marrow stromal cells (BMSCs) of patients with multiple myeloma (MM) and a healthy control. The new findings of this paper is that BMSCs of the MM patients exhibited intrinsic MMP-1, MMP-2 and TIMP-2 overproduction. Production of MMP-1, TIMP-2 and activation of MMP-2 was additionally enhanced in co-cultures of BMSCs with RPMI8226 cells. The ratio between MMP-2 and TIMP-2 was significantly higher in BMSCs of the MM patients than in control. BMSCs of both the control and the MM patients exhibited the presence of MMP-9 latent form, but in co-cultures RPMI8226 cells were the main producers of this metalloproteinase.