NF-κB signaling is necessary for Tax-mediated induction of Fascin. (A) Fascin mRNA (quantitative PCR) and protein after transfection of Jurkat T cells with expression plasmids for NF-κB-deficient Tax-mutants M7 and M22 compared with wt-Tax (pcTax) and M47. The means of 3 independent experiments ± SE are shown in the upper panel. (B-C) Quantitative PCR of (B) Fascin and (C) Tax mRNA after transfection of expression plasmids for wt-Tax (20 μg) and IκBα-DN (2 μg) in Jurkat T cells. Mean values were compared using a paired t test (n = 3). **P < .01. (D) Immunoblot of Fascin after transfection of pcTax and cotransfection of pIκBα-DN or treatment with the IKK-β inhibitor ACHP solved in dimethyl sulfoxide. ACHP (10μM; 25μM) was added 24 hours after transfection for 24 hours. (E) Quantitative PCR of Fascin and 4-1BB mRNA after treatment of HTLV-1–transformed MT-2 cells and Tax-transformed Tesi cells with increasing amounts of ACHP (1, 2.5, 5, 10, and 25 μg) for 48 hours. Relative copy numbers were normalized on values obtained in dimethyl sulfoxide–treated cells.