AEP partially facilitates cell invasion. (A) SD1 cells demonstrate increased invasion compared with REH and SupB15 (P < .0001; left panel) and invasion is significantly (P < .0001) inhibited by the AEP inhibitor AEPi (100μM; right panel). (B) AEP transcript knockdown (SD1^AEPkd) results in a marked decrease in AEP expression (right panel) and activity (middle panel) and a decrease but not complete inhibition of invasion (P = .003; left panel). (C) Expression of AEP in REH (REH^AEPwt) results in a marked increase in AEP expression (right panel) and activity (middle panel) but only a modest increase in invasion (P = .01; left panel). All assays were performed in triplicate and the data shown summarize results of 3 separate experiments. For invasion assays, error bars represent SEM. Activity assay results are shown as fluorescent intensity per well ± SEM. AEP precursor (56 kDa) and activity (36 kDa) are detected. Dashed lines denote spliced noncontiguous lines within gels.