In vivo antimyeloma activity of a DUB inhibitor. (A) NSG mice with equal size-matched dorsal MM1.S tumors were treated with the indicated dose of G9 every day for 2 weeks. Tumor size was measured at the time points indicated. Each bar represents the average ± SD of tumor size from 5 animals. P values are shown within the figure. (B) Animal body weight was measured in control and G9-treated mice from Figure 7A. Body weight was measured at the interval noted, and each bar represents the average ± SD from 5 mice per group. (C) MM1.S tumors growing in NSG mice (3 per group) were treated daily with the indicated concentration of G9. Tumor volumes at each designated interval were recorded. The average tumor volume ± SD from 3 mice per group is shown. P values are the same as described in Figure 7A. (D) Tumors from Figure 7C were excised at the conclusion of the study (day12) and photographed. (E) One hour after the final G9 treatment, tumors from control and G9-treated (15 mg/kg) mice were excised, quick frozen in liquid nitrogen, and subjected to lysis. Equal protein lysates from these tumors was subjected to DUB activity assessment (top; as in Figure 1A) and immunoblotted for the protein indicated. The top band represents HA-UbVS–labeled Usp9x and Usp24 (co-migrating proteins).