Figure 2

MMP-1 suppression inhibits invasion ability but not migration ability of 231-BR3 and 231-BR cell lines in vitro . A, 231-BR cells, 231-BR3 cells, control shRNA and MMP-1 shRNA expressing cells were tested for their ability to migrate to 5% FBS in the lower chamber of Transwell chambers. 2.5×10⁴ cells were seeded in the migration chamber in serum-free medium. Migrated cells were fixed and counted after 24 h. MMP-1 knockdown in BR and BR3 cells did not affect cell migration ability. The data shown were combined from 5 independent experiments. B, control shRNA and MMP-1 shRNA expressing BR and BR3 cells were tested for ability to invade across a Matrigel-coated membrane in response to 5% FBS in the lower chamber. 2.5×10⁴ cells were seeded in the invasion chamber in serum-free medium. Invaded cells were fixed and counted after 24 h. Asterisks indicate significant differences (P < 0.05) between control shRNA expressing cells and MMP-1 shRNA expressing cells. The data shown were combined from 5 independent experiments.