Fig. 9.

Effect of COX and LOX inhibitors on PGE₂ release and proliferation in Colon-26. A, effect of COX inhibitors on PGE₂ release. Quiescent Colon-26 cells were preincubated with 20 μM aspirin, ibuprofen, indomethacin, or rofecoxib for 20 min before adding mGX sPLA₂ (200 nM) for 24 h. Supernatants were collected and analyzed for PGE₂ by enzyme-linked immunosorbent assay as described under Materials and Methods. B and C, effect of COX inhibitors on mGX- and AA-induced cell proliferation. Quiescent Colon-26 cells were preincubated with COX inhibitors for 20 min before adding mGX sPLA₂ (B) or AA (C). The -fold increase in [³H]thymidine incorporation over untreated cells is shown. Under untreated conditions, the incorporation of [³H]thymidine was 41,719 dpm. D, effects of the 5-LOX inhibitor MK886 (10 μM) and the 12-LOX inhibitor baicalein (10 μM) on Colon-26 cell proliferation. Under untreated conditions, the incorporation of [³H]thymidine was 39,550 dpm. A representative experiment of at least two experiments is shown in the different panels, and results statistically significant over their respective controls are indicated (**, P < 0.001; one-way ANOVA, with Bonferroni adjustment).