Figure 5. Phosphatidylinositol 3-kinase (PI-3K)//Akt inhibition suppresses hepatocyte growth factor (HGF)– and keratinocyte growth factor (KGF)–mediated effect on p27^kip expression. Rabbit corneal primary epithelial (RCPE) cell growth cultures at 80%–90% confluence were starved overnight with Dulbecco’s Modified Eagle Medium with Ham’s F-12 (DMEM/F-12)/0.25% fetal calf serum (FCS) and then pretreated with PI-3K/Akt inhibitor (LY294002, 20 μM) and Erk inhibitor (PD98059, 20 μM) for 30 min before 20 ng/ml HGF) or KGF was added. Cultures were incubated for various time points as indicated, and the levels of (A) p27^kip and (C) phospho Akt (pAkt) in cellular extracts were determined with western immunoblotting. Densitometric quantification of p27^kip levels is presented in B. Data shown are mean±standard deviation (SD). p<0.05, *HGF versus LY+HGF, #KGF versus LY+KGF.