(A) FOXC1- or vector-overexpressing MDA-MB-231 cells were treated with the NF-κB inhibitor BMS-345541 (2 μM), followed by MTT assays (left), transwell migration assays (middle), and transwell invasion assays (right). Data represent mean ± SD (n = 3). (B) Wild-type (wt) and IKKα/IKKβ-null MEFs were transfected with FOXC1 or the vector, followed by cell proliferation MTT assays at the indicated time points (left). Deficiency of IKK expression in knockout MEFs is shown by immunoblotting (right). (C) Wild-type (wt) and IKKα/IKKβ-null MEFs were transfected with FOXC1 or the vector, followed by cell cycle analysis using flow cytometry (left). *, P < 0.05. CyclinD1 expression was assessed by immunoblotting (right).