Heparanase expression promotes tumor growth in vivo. (A) Following injection of heparanase-transfected (▪) or control-transfected (▴) CAG myeloma cells into SCID mice, sera were harvested at specific intervals and analyzed for the level of human immunoglobulin kappa light chain as a measure of tumor burden (n = 10 for heparanase-transfected, n = 7 for control-transfected; P < .002 at week 8). Values represent the mean plus or minus SD of each group of animals as derived from duplicate samples from each animal within the group. Sera were not collected at week 6. (B) Heparanase-transfected (▪) and control-transfected (□) cells exhibit identical growth rates in vitro. Cells were plated at equal cell numbers and analyzed by MTT assay at 24, 48, and 72 hours after plating. Values represent means of duplicate samples plus or minus SD. OD indicates optical density.