Gelatinase expression in human myeloma cells. Gelatin zymography of 48-hour serum-free conditioned media was performed on equal aliquots (15 μL) as described in the Materials and Methods. (A) Lanes 1 through 3 and 5, purified myeloma cells from bone marrow of patients with MM; lane 4, purified myeloma cells from peripheral blood of a patient with PCL. (B) Supernatants of purified myeloma cells were treated for 24 hours by APMA (10 mmol/L; lane 2), EDTA (10 mmol/L; lane 3), or 1-10 Phenanthroline (1 mmol/L; lane 4) at 37°C. (C) Lanes 1 through 3, HMCL NCI-H929, RPMI-8226, and SBN-1; lane 4, primary tumor myeloma cells that engendered SBN-1.