ABC294640 suppressed myeloma growth in vivo in mouse xenograft models. (A) ABC294640 inhibited myeloma growth in vivo in the intravenously administrated mouse xenograft model. NOD/SCID IL-2γ null (NSG) mice were sublethally irradiated (2.5 Gy) and injected via tail vein 0.5 × 10⁶ MM.1S myeloma cells stably expressing luciferase. Two days later, the mice were divided randomly into 2 groups and treated with either ABC 294640 50 mg/kg intraperitoneally (A) or a control vehicle (C) (phosphate-buffered saline + 0.3% Tween-80) for 30 days. Every 10 days, the mice were imaged using the Perkin Elmer Ivis 200 imager and Live Image software. (B) ABC294640 inhibited myeloma growth in vivo in the subcutaneously inoculated mouse xenograft model. NSG mice were sublethally irradiated (2.5 Gy) and injected subcutaneously with 0.5 × 10⁶ MM.1S myeloma cells stably expressing luciferase. Two days later, the mice were treated with either ABC294640 50 mg/kg intraperitoneally (mice indicated as “A”) or control vehicle (mouse “C”) for 30 days. Tumor growth was monitored by bioluminescence imaging. (C) ABC294640 inhibited myeloma growth in vivo. NSG mice were sublethally irradiated (2.5 Gy) and injected subcutaneously with 0.5 × 10⁶ MM.1S myeloma cells stably expressing luciferase. Two weeks later, the mice were imaged using bioluminescence imaging and showed tumor engraftment (D0). The mice were then treated with ABC294640 50 mg/kg intraperitoneally or control daily for 27 days (from D0 to D27). Tumor growth was monitored by bioluminescence imaging at time-points indicated (up to 1 week after the discontinuation of injection [ie, D35]). (D) Schematic diagram of the mechanisms of action of ABC294640 in MM cells.