Effect of MAP kinase and NF-κB inhibitors on MMPs secretion from SOCS1-knockdown SW1353 cells. SOCS1-knockdown SW1353 cells were pretreated with inhibitors for 1 hour before stimulation with 10 ng/ml of IL-1β. After 24 hours, the levels of MMP-1, -3, and -13 were dramatically decreased by SB202190, a p38 MAP kinase inhibitor (A). Blockade of C-JNK (B) and ERK (C) dose-dependently suppressed the secretion of MMPs from shSOCS1-transfected SW1353 cells. The production of MMP-1 and MMP-13 was partially inhibited with the SN50, a specific NF-κB inhibitory peptide (D). Data were expressed as the mean ± SEM of relative MMPs levels, as compared with the control without inhibitors (n = 3). *P < 0.05 by Kruskal-Wallis test.