Effect of celecoxib on proliferation, collagen expression, ERK1/2 and SMAD2/3 phosphorylation in NIH/3T3 fibroblasts

In the present study, the effects of celecoxib on proliferation, collagen expression, ERK1/2 and SMAD2/3 phosphorylation in NIH/3T3 fibroblasts were investigated. NIH/3T3 fibroblasts stimulated with fibroblast growth factor-2 (FGF-2) or transforming growth factor-beta 1 (TGF-beta 1) were examined in the presence of celecoxib. Proliferation was assessed by MTT assays; ERK1/2 expression and SMAD2/3 expression were assessed by quantitative RT-PCR and western blotting; ERK1/2 phosphorylation and SMAD2/3 phosphorylation were assessed by western blot analysis. The results indicated that celecoxib could suppress cell proliferation stimulated by FGF-2 (IC50 FGF+group, 75 +/- 1.9 mu mol/l) and TGF-beta 1 (IC50 TGF+group, 48 +/- 1.4 mu mol/l), by inhibiting ERK1/2 phosphorylation but not ERK1/2 expression. Celecoxib also suppressed collagen expression (0.35-fold COL3 and 0.43-fold COL1 at 320 mu mol/l celecoxib relative to the untreated control after stimulation with TGF-beta 1 for 3 h, P<0.01), by inhibiting SMAD2/3 phosphorylation but not SMAD2/3 expression. The suppression of NIH/3T3 fibroblast proliferation and collagen expression upon stimulation by FGF-2 and TGF-beta 1 is likely a result of the inhibition of ERK1/2 and SMAD2/3 phosphorylation by celecoxib. (C) 2011 Elsevier B. V. All rights reserved.