Inhibition of constitutive NF-κB promoter activity and VEGF production by Src kinase inhibitor PP2 in K1 lymphoma–derived KVL-1 cells. KVL-1 cells (2 × 10⁶) that express K1 were transfected with 10 μg of NF-κB–luciferase reporter construct. After 20 hours, the cells were treated with the Src kinase inhibitor PP2 (13 μM) or its inactive analog PP3 (13 μM) for 4 hours, harvested, and assayed for NF-κB activity (□) in cell extracts and for VEGF production (▪) in culture supernatants as described in “Materials and methods.” Luciferase values are expressed as a percentage of activities observed in the absence of inhibitors (bar 1). Data are presented as the means (± SD) of 3 experiments. There were statistically significant (^*P < .001) decreases in NF-κB–luciferase activity and VEGF production in the cells treated with PP2.