Fig. 1.

Anti-human CD81 5A6 mAb inhibits human breast cancer invasion and migration in vitro. (A and B) 3 × 10³ MDA-MB-231 or (C) MDA-MB-436 cells were seeded in a 96-well round-bottom plate in 1× spheroid formation ECM and incubated for 48 to 72 h to promote sphere formation. Then invasion matrix was added containing 10 µg/mL of anti-CD81 IgG1 mAbs (5A6, 1D6, JS81, or 1.3.3.22) or isotype control mAb. Photographs were taken at 72 h and invaded areas were analyzed using ImageJ software. Shown are mean ± SEM, Student’s t test, P = 0.0001***. (D) 1 × 10⁵ human MDA-MB-231 cells were starved in 0.1% FBS-containing RPMI media overnight. The next day cells were incubated with 10 µg/mL of mouse anti-human CD81 5A6 IgG1 or isotype control mAb before placing them on the top Transwell chamber. Cells that migrated after 5 h to the bottom chamber were quantified by crystal violet staining (n = three independent experiments). Shown are mean ± SEM, Student’s t test, P = 0.0002***.