Constitutive NF-κB activation in MCL cell lines. (A) Electrophoretic mobility shift assay (EMSA) of whole cell extracts from 1.0 × 106 cells of EBV-negative MCL cell lines probed with 32P-radiolabeled oligonucleotide containing the consensus NF-κB binding sequence. Oct-1 binding is shown as a loading control. Assignment of the NF-κB complexes are based on supershift analysis shown in (B). (B) Supershift EMSA of whole cell extracts from MCL cell lines.