Figure 1.

Inhibitory effect of PI 3-kinase and ERK1/2 inhibitor on cell proliferation stimulated by FGF-2. Cell proliferation was determined by MTT assay. The serum-starved hCECs were pretreated with LY294002 for PI 3-kinase inhibition or U0126 for ERK1/2 inhibition for 2 hours and then maintained in DMEM with FGF-2 for 24 hours. At the end of incubation, MTT was added for 4 hours and then intracellular purple formazan, the MTT metabolic product by the action of dehydrogenase enzymes of metabolically-active cells, was quantified with a spectrophotometric plate reader at dual wavelengths of 570 and 650 nm. Data were normalized to cells maintained in DMEM without serum. D-0, DMEM without serum; F-2, FGF-2; LY, LY294002; U, U0126. The graphs represent the mean ± SEM from three independent experiments. (*P = 0.0009, paired t-test; **P = 0.0002, paired t-test).