Retrovirus transduction of IRES-EGFP control (control), human survivin IRES-EGFP (h-survivin), mouse survivin IRES-EGFP (m-survivin), and antisense survivin-IRES-EGFP (AS-m-survivin) into primary mouse bone marrow cells.

(A) GFP-positive bone marrow mononuclear cells in each transduced group were FACS sorted and the percentage of survivin-positive cells was determined by flow cytometry after staining with PE-antisurvivin antibody. Data are expressed as means ± SEM from 2 experiments. Western analysis for survivin in GFP⁺mononuclear cells from each transduced group is shown in the insert. The same filter was stripped and reprobed with antihuman actin antibody as a loading control. Cross-reactivity of this antibody to mouse has been validated by the manufacturer. (B) CFU-GM production in transduced mouse bone marrow cells. Ten thousand GFP-positive marrow mononuclear cells were cultured in soft agar with 10 ng/mL rmGM-CSF and 50 ng/mL rmSCF and CFU-GM quantitated after 7 to 10 days at 37°C, 5% CO₂, 5% O₂ in air. The average number and SEM of CFU-GM from triplicate plates of 4 individual experiments are shown. Combined data from all 4 experiments are shown in the insert. Retrovirus harboring human survivin was used in experiments 1, 3, and 4. Mouse survivin was used in experiments 2, 3, and 4. Vector backbone and antisense-mouse survivin were used in all 4 experiments. *P < .005; **P < .001. (C) The proportion of CFU-GM in S phase of the cell cycle was determined by thymidine suicide with high specific activity [³H]thymidine. Data are the averages ± SEM of 3 independent experiments.