LY294002 inhibits H. pylori -induced IL-8 expression and production. (A) MKN45 cells were preincubated with LY294002 (20 μM) for 60 min prior to infection with H. pylori (ATCC 49503), harvested at the indicated time points and assayed for IL-8 mRNA expression by RT-PCR. Lane M contains markers. (B) LY294002 inhibits H. pylori-induced IL-8 production. MKN45 cells were preincubated with the indicated concentrations of LY294002 for 60 min prior to infection with H. pylori (ATCC 49503). For IL-8 protein determination, supernatants were collected 24 h after infection and assessed for IL-8 production by ELISA. Data are mean ± SD of three experiments.