17-DMAG significantly promoted bone marrow cell viability after irradiation. Mice were administered with 17-DMAG or vehicle 24 h prior to irradiation at 9.25 Gy. (A) Bone marrow cell viability by trypan blue exclusion: total numbers of live bone marrow cells collected from each femur bone of mouse at days 3, 7 or 15 after irradiation were measured by trypan blue staining. Irradiation reduced bone marrow cell viability with a significant reduction of total live cell numbers in all three time points. 17-DMAG significantly increased bone marrow cell viability at days 7 and 15 after irradiation (N = 4–6 mice per group). At day 3, * p < 0.05 vs. Veh/sham, 17D/sham. At days 7 and 15, * p < 0.05 vs. Veh/sham, 17D/sham, and 17D/RI; ** p < 0.05 vs. Veh/sham, 17D/sham, and Veh/RI. Error bars indicate the SEM for 4–6 independent experiments at various time points. (B) Bone marrow cell viability by flow cytometric assay: twenty thousands of bone marrow cells from each femur bone of mouse pre-treated with either 17-DMAG (left) or vehicle (right) at day 15 after irradiation were stained with 7-aminoactinomycin D (7AAD). 17-DMAG increased bone marrow cell viability with a greater percentage of 7AAD-negative cells. Error bars indicate the SEM for at least three independent experiments. (C) Using Western blotting, decreased CD34 and CD 44 protein were detected in bone marrow cells from femur bone of Veh/RI-mice at day 30 after irradiation at 8.75 Gy; 17-DMAG blocked the RI-induced suppression in both CD34 and 44 protein expression at day 30 after irradiation. * p < 0.05 vs. Veh/sham, 17-D/sham, and 17D/RI. Error bars indicate the SEM for 4–5 independent experiments. Veh: vehicle; 17-D: 17-DMAG; RI: radiation injury.