(A) The activity of MMP-2 was analyzed by gelatin zymography using conditioned medium of A172 cells treated for 24 hours with dimethyl sulfoxide vehicle (DMSO) (0), or with a chemical inhibitor of MMP2 activity (ARP-100; iMMP2) at different concentrations. C+, positive control for MMP2 and MMP9, conditioned medium of a gastric cell line stimulated with macrophages. (B, C, D) Cells treated with DMSO or with ARP-100 were cultured for 24 hours on Matrigel coated filters. Data on graphs represent the mean values ± standard errors and are representative of, at least, three independent experiments. *, significantly different from A172 treated with DMSO (p < 0.05), **, significantly different from A172.Ev cells treated with DMSO (p < 0.01), ***, significantly different from SW 1088 C- or SW1088 shW2 cells treated with DMSO (p < 0.001).