CPA-induced cell death is inhibited by adenovirus delivered p35. A) Caspase activity in U251 cells infected by Adeno-2B6 or Adeno-2B6/p35 for 48 hr (MOIs 0-40, as indicated) and treated with 1 mM CPA for 48 hr, as specified. Adeno-2B6 increased and Adeno-2B6/p35 decreased basal, and CPA-induced caspase activity in a virus dose-dependent manner. Caspase activity is expressed in arbitrary fluorescent units, with a dashed horizontal line indicating the basal caspase activity of uninfected cells in the absence of CPA treatment. B) Growth inhibition assay showing that CPA-induced U251 cell death is decreased in cells infected with Adeno-2B6/p35, as compared to cells infected with Adeno-2B6 (mean ± SD, n = 3, based on crystal violet staining quantified by A595).