Effects of epidermal growth factor (EGF) on platelet-activating factor (PAF) production in ovarian cancer cells. (A and B) Release of PAF in response to increasing concentrations of EGF for 1 h. CAOV3 and SKOV3 cells were serum starved and then stimulated with indicated concentrations (0.5 to 100 ng/ml) of EGF. (C and D) Time course of PAF increase in response to 10 ng/ml EGF. CAOV3 and SKOV3 cells were treated with EGF for the indicated time (20 min to 24 h) while measuring PAF production. Bars represent the average of triplicates ± S.D.; “*” (p < 0.05) and “**” (p < 0.01) indicate a statistically significant difference compared to the untreated control.