SNCG promotes MMP-9 expression through p38MAPK. (A) HepG2 and HeLa cells were transfected with 1 μg/ml of the empty vector or SNCG expression plasmid, and then treated with or without 50 μM of SB203580 for another 48 h, followed by western blot analysis of indicated proteins. (B) HepG2 and HeLa cells were transfected with 1 μg/ml of the empty vector or SNCG expression plasmid, and then transfected with siControl or siP38α, followed by western blot analysis of indicated proteins. (C) HepG2 and HeLa cells were transfected with 50 nM of siControl or siSNCG. 24h later, the cells were treated with or without 5 ng/ml of TGF-β for another 48h, followed by western blot analysis of indicated proteins. (D) HepG2 and HeLa cells were transfected with 1 μg/ml of the empty vector or Twist1 expression plasmid, and then transfected with siControl or siSNCG, followed by western blot analysis of indicated proteins.