Fig. 4

MMP-9 inhibitors abolished PMA-inducedN-cadherin cleavage. NPC cells were pre-treated with (a) GM6001 (GM, 10–20 μM) or (b) a specific MMP-9 inhibitor (20 μM) for 2 h, then co-incubated with PMA (100 nM) for 24 h. Cell lysates underwent immunoblotting with the indicated antibodies. The relative band intensities of FL/N-cad were compared with the control group (PMA-untreated cells), and relative expression (RLE) of N-cadherin is shown as the ratio of GM-plus-PMA–treated group to PMA treatment alone. c The effect of pro-MMP-9 or activated MMP-9 on the cleavage of N-cadherin.Pro-MMP-9 (R&D, 911-MPN-010) was activated by incubation in TCNB buffer for 24 h at 37 °C. NPC-TW039 cells were exposed to activated MMP-9 or pro-MMP-9 (0.1 nM) for 7 h. Cell lysates underwent western blot analysis with anti-N-cadherin antibody. The relative expression of FL/N-cad was compared to the control group (activated MMP-9-untreated cells); N = 3, ^*P<0.05