a The inhibitory effect of omeprazole on the migration of serum-stimulated HCT116, SUM159, and 4T1 cells. b The inhibitory effect was quantified as described in a (n = 3). c The levels of Snail, Slug, Twist, and ZEB1 in cancer cells treated with omeprazole were evaluated by immunoblotting. d The levels of Snail, Slug, Twist, ZEB1, E-cadherin, and vimentin in the presence of TGFβ1 (2 ng/ml) in cancer cells treated with omeprazole were evaluated by immunoblotting (n = 3). e Immunofluorescence staining of E-cadherin and vimentin in MMTV-PyMT (left) and 4T1 (right) cells as described in d. Nuclei were counterstained with DAPI (blue). Data are presented as the mean ± SD. One-way analysis of variance was used for statistical analysis. **P < 0.01 vs. vehicle.