Figure 3. CHR-3996 overcomes the protective effect of the bone marrow microenvironment.

Bone marrow stromal cells were cultured from bone marrow aspirates obtained from three patients with myeloma. A. The bone marrow stromal cells were treated with a range of CHR-3996 concentrations for 24 hours. The number of viable cells was measured by metabolic activity (WST-1 assay) and is shown as a percentage of untreated cells. B. H929 (i) or RPMI-8226 (ii) cells were treated with CHR-3996 in the presence or absence of the bone marrow stromal cells (performed in triplicate) for 24 hours. The proliferation of the cells was monitored by metabolic activity (WST-1 assay) and is shown as a percentage of untreated cells. IL-6 C. and VEGF D. secreted by the bone marrow stromal cells over 24 hours in isolation or in a co-culture with H929 or RMPI-8226 cells and with or without CHR-3996 treatment were measured by ELISA. The data was compared using a one-tailed paired Student's T Test and ** indicates a p value of <0.05.