CCL2 promotes the EMT in MNNG-pretreated GES-1 cells. The GES-1 cells were pretreated with MNNG and subsequently induced with CCL2 for 9 days. (A) Representative images of the cells (magnification, ×100; scale bar, 100 µm). (B) A Transwell migration assay was performed to assess the migration capacity of the cells (magnification, ×100; scale bar, 100 µm; *P<0.05). (C) Western blotting was performed to determine the protein expression levels of E-cadherin and N-cadherin. Immunofluorescence staining was performed to determine the protein expression levels of (D) E-cadherin and (E) N-cadherin (magnification, ×200; scale bar, 50 µm). Ctrl, GES-1 cells; MNNG, N-methyl-N-nitro-N′-nitrosoguanidine-pretreated GES-1 cells; CCL2, CC chemokine ligand 2; MNNG+CCL2, MNNG-pretreated GES-1 cells induced with CCL2 for 9 days.