Inhibition of cell adhesion and directional transmigration by L1CAM antibodies. MDA-MB-231 cells pre-treated with control isotype IgG or either of the two anti-L1CAM monoclonal antibodies targeting its ectodomain (5G3 or UJ127) were added into 96-well plates coated with fibronectin (A) or Matrigel™ (B) for adhesion assay as described before. The antibody was also present during the incubation time. (C) Conditioned medium with 0.5% BGS from each cell culture system shown on X-axis was collected and added into the lower chamber as chemoattractant in transmigration assay. Where indicated, L1CAM antibody 5G3 or isotype IgG were added at 2 μg/mL in the lower chamber. MDA-MB-468 cells were seeded in serum free medium in the top and allowed to migrate for 12 hours. Migrant cells to the underside were stained and counted for 5 random fields to obtain the average. *, p < 0.05 vs. conditioned medium from MDA-MB-468; #, p < 0.05 vs. treatment with control antibody.