Fig. 1.

Cyclooxygenase (COX)-2 protects against TNF cytotoxicity in colon and gastric epithelial cells. A: young adult mouse colon (YAMC), COX-1^−/−, and COX-2^−/− mouse colon epithelial (MCE) cells were treated with TNF (100 ng/ml) for 48 and 72 h, and cell number was assayed using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay. Data points represent percentage of cell loss relative to mock treatment. *P < 0.05 vs. YAMC. #P < 0.05 vs. COX-1^−/−. B: immortalized mouse stomach epithelial (ImSt) and COX-2^−/− ImSt cells were treated with TNF (100 ng/ml) for 48 and 72 h, and cell number was assayed using the NucleoCounter automated cell counter. Data points represent percentage of cell loss relative to mock treatment. *P < 0.05 vs. respective ImSt time point. #P < 0.05 vs. respective 48-h time point. C: COX-1 and COX-2 protein expression in YAMC, COX-1^−/−, and COX-2^−/− MCE cells. Cells were treated with TNF (100 ng/ml) and epithelial growth factor (EGF, 10 ng/ml) for 24 h, and protein expression in cell lysates was determined by Western blot analysis. IB, immnoblot.