Effects of oligonucleotides on the proliferation of bone marrow cells selected for CD34 expression and incubated with FL plus IL-3. CD34⁺ cells were seeded at a concentration of 5,000 cells/mL and incubated in medium supplemented with FL at 50 ng/mL and IL-3 at 25 ng/mL to promote monocytic growth. On days 0, 5, and 10, antisense RB oligonucleotides (AS2), sense-orientated oligonucleotides (SO2), scrambled oligonucleotides (SCR), or oligo buffer, respectively, were added at a concentration of 5 μmol/L. On days 7 and 14, cells were counted. Results shown represent the mean values from 3 separate experiments (bars ± SEM). Results from SCR are from 2 independent experiments. Viability was always greater than 90% (data not shown).