PGE2 upregulates uPA and MMP-9 via JNK1/2 signaling pathway in human LoVo colon cancer cells. (A) LoVo cells were pretreated with vehicle, LY294002 (Akt activation inhibitor), U0126 (ERK1/2 activation inhibitor, 1 μM), SB203580 (p38 MAPK inhibitor, 1 μM), SP600125 (JNK1/2 inhibitor, 1 μM) or QNZ (NFκB inhibitor, 1 μM) for 1 h and followed by PGE2 (10-6M) administration for 24 h, and then were harvested for immunoblotting assays. (B) LoVo cells cultured in DMEM were treated with PGE2 (10-6M) for various periods (15 min, 30 min, 1 h, 3 h, 6 h, 12 h and 24 h), and subsequently measured the phosphorylation/activation of proteins by immunoblotting assay. The fold ratio of p-JNK1/2 and JNK1/2 was measured. Total protein of cell extracts was separated by 12% SDS-PAGE, transferred to PVDF membranes, and immunoblotted with antibodies against uPA, MMP-9 (A), phospho-JNK1/2 and JNK1/2 (B) proteins. Equal loading was assessed with an anti-α-tubulin antibody. **, p < 0.01 versus control (mean ± SE, n = 3).