FIG. 9.

Production of PGE₂ in AZ-521 cells by VacA, its inhibition by NS-398, and overexpression of a DN-p38. (A) Confluent AZ-521 cells were incubated without (open bars) or with 25 ng/ml EGF (hatched bars) or 120 nM VacA (solid bars) for 0, 6, or 12 h at 37°C. The medium was collected, and PGE₂ was measured by enzyme immunoassay. *, P < 0.001; **, P < 0.02. (B) To assay the effects of NS-398, cells were preincubated with the indicated amount of NS-398 for 30 min, followed by incubation without (open bars) or with 25 ng/ml EGF (hatched bars) or 120 nM VacA (solid bars) for 12 h at 37°C. *, P < 0.05; **, P < 0.01. (C) AZ-521 cells transfected with pcDNA3 vector or a Flag-tagged DN-p38 construct were incubated with control solution (open bars), 120 nM VacA (solid bars), or EGF (25 ng/ml) (hatched bars) for 0 or 12 h. The medium was collected, and PGE₂ was measured by enzyme immunoassay. Data are means ± standard deviations of values from three separate experiments. *, P < 0.008; **, P < 0.002.