Bcl-2-ASO–induced apoptosis in HS-Sultan, ARH-77, U266, and ARP-1 myeloma cells.

U266 (high Bcl-2), ARP-1 cells (low Bcl-2), and ARP-1/Bcl-2 cells (high Bcl-2) were incubated with 0 to 10 μg/mL Bcl-2-ASO or with reverse sense Bcl-2 oligodeoxynucleotides for the time points indicated as described in “Materials and methods.” Apoptosis was determined by annexin V. Bcl-2-ASO and reverse sense oligodeoxynucleotides were replenished every other day. U266 cells express about 3-fold higher levels of Bcl-2, and ARP/Bcl-2 expresses about 10-fold higher Bcl-2 relative to ARP-1 cells (Figure 1). ARP/Bcl-2 cells were generated and maintained as described before.9 Bars are ± SD of at least 3 experiments. For additional experimental details, see “Materials and methods.” R-SENSE indicates reverse sense Bcl-2-ASO.