Introduction: Activity of metalloproteinases (MMP) is controlled both by specific tissue inhibitors (TIMP) and activators (extracellular matrix metalloproteinase inducer, EMMPRIN). There are few data available concerning concentration the bone marrow of MMP-2, MMP-9, TIMP-1, and TIMP-2, or EMMPRIM expression by bone marrow mesenchymal stromal cells (BMSCs) in patients with multiple myeloma (MM).
Patients and methods: We studied 40 newly diagnosed, untreated patients: 18 males and 22 females with de novo MM and 11 healthy controls. Bone marrow was collected prior to therapy. BMSCs were derived by culturing bone marrow cells on MesenCult. Protein concentrations were determined in bone marrow plasma and culture supernatants by ELISA. EMMPRIN expression by BMSCs was assessed by flow cytometry.
Results: The median concentrations of MMP-9, TIMP-1, and TIMP-2 in both marrow plasma and culture supernatants were significantly higher in MM patients than controls.
Conclusion: EMMPRIN expression and ratios MMP-9/TIMP-1 and MMP-2/TIMP-2 were higher in MM patients, our results demonstrate that in MM patients MMP-2 and MMP-9 are secreted in higher amounts and are not balanced by inhibitors.
Keywords: EMMPRIN; Metalloproteinase-2; Metalloproteinase-9; Multiple myeloma.