Upregulation of NF-κB activity is associated with the EMT phenotype in TG2-overexpressed A431-P cells. (A) A431-P cells were transfected with empty pcDNA3.1 vector or pcDNA3.1-TG2. Cellular protein levels of IκBα and TG2 were determined at 48 h post-transfection by immunoblotting. (B-E) Cells were treated with or without 25 μM of specific NF-κB inhibitor JSH-23 for 24 h. (B) Cellular NF-κB activity was determined using a luciferase reporter assay. (C) Cellular protein levels of Snail and TG2 were detected by immunoblotting. (D) The secreted activity of MMP-9 was analyzed by gelatin zymography. (E) Cell migratory activity was determined using a wound healing assay. Quantitative data are presented as the mean (± SD) percentage of migration distance (n = 20). * indicates a significant difference compared with the respective control (p < 0.05). # indicates a significant difference compared with the A431-P (p < 0.05).