FIG. 10.

The p38 pathway plays a dominant role in the regulation of Cox-2 gene expression. (A) HeLa-TO cells were incubated in the absence or presence of 1 μM SB203580 (SB), 1 μM dexamethasone (Dex), or both together for 1 h prior to UV stimulation. After a further 1 h, cells were harvested and RNase protection assays were performed to quantify Cox-2 and GAPDH mRNAs. Mean Cox-2/GAPDH mRNA ratios from a representative experiment are shown (with standard deviations, n = 4). (B) HeLa-TO cells were transfected as described in the legend to Fig. 2, using the reporter construct pTetBBB-Cox2.5. After 24 h, the cells were incubated with 1 μM dexamethasone, 1 μM SB203580, or both for 1 h and then stimulated with UV (40 J/m²). After a further 1 h, tetracycline (Tet) was added, the cells were harvested at the time intervals shown, and RNase protection assays were performed as described in the legend to Fig. 2. Only the β-globin reporter and GAPDH loading control are shown. (C) Graphical representation of the experiment in panel A. Each transfection was performed three times, with qualitatively identical results.