Fig. 9.

Effect of FGF receptor antagonist or Erk1/2 MAPK inhibitor on KGF2-induced stimulation of Pgp promoter activity in Caco-2 cells. Caco-2 cells were transiently transfected with MDR1 luciferase promoter construct (p-1,073/+703) along with pCMVβ vector. After 24 h, transiently transfected cells were pretreated with the specific antagonist of FGF receptor PD-161570 (10 μM) (A) or the Erk1/2 MAPK inhibitor U-0126 (10 μM) (B) for 60 min in media containing 0.2% BSA and 1% FBS and then coincubated with KGF2 (10 ng/ml) in media containing 1% FBS for 24 h. Posttransfection (48 h) the promoter activity was measured by luciferase assay. Values were normalized to β-galactosidase activity to correct for transfection efficiency. Results represent means ± SE of 3 separate experiments and are expressed as %control comparing transfected cells treated with KGF2 with untreated cells (control). *P < 0.05 compared with control.