Inhibition of p65 expression induces apoptosis in HS-Sultan and RPMI-8226 cells. (A) HS-Sultan, RPMI-8226, and K562 cells mock-transduced (-) or transduced with the LV-shp65 or the mutated control LV-shC vectors were lysed 72 hours after infection, and whole-cell lysates were immunoblotted with antibodies to p65, GFP, and α-tubulin, as a loading control. (B) Growth-inhibiting function of p65 RNA interference in HS-Sultan and RPMI-8226 cells. HS-Sultan (left), RPMI-8226 (middle), and K562 cells (right) were transduced with the PGK-GFP LV-shC (♦) or LV-shp65 (▪) lentiviral vectors. The percentage of GFP-positive cells was determined by flow cytometry and monitored every 48 hours beginning at day 3 after infection for a period of 2 weeks. Decrease of GFP-positive population over time indicates a relative growth disadvantage. (C) p65 RNA interference induces apoptosis in HS-Sultan and RPMI-8226 cells. (Left) Histograms of FACS analysis of annexin V staining in HS-Sultan cells 5 days after infection with LV-shp65 or control LV-shC vectors. (Right) Apoptosis in HS-Sultan, RPMI-8226, and K562 cells transduced with either LV-shp65 (▪) or control LV-shC (□) vectors was evaluated by FACS analysis of annexin V⁺ cells 4 days after transduction. The results are representative of 3 independent experiments.