Inhibition of Nuclear Factor-kappaB (NF-κB) by Ro 106-9920 decreases mPGES-1 and COX-2 expression. (A) Gingival fibroblasts were treated with TNFα (20 ng/ml) with or without the NF-κB activation inhibitor Ro 106-9920 (Ro, 4.0 μM) for 24 h. Expression of mPGES-1 and COX-2 was measured by flow cytometry using specific antibodies. (B) Gingival fibroblast were cultured with Ro (4.0 μM) in the absence or presence of TNFα (20 ng/ml) for 24 h. Levels of PGE2 in the culture media were measured by EIA, and data is presented as mean ± s.d. Asterisk (*) indicates a significant difference compared to control cells not treated with TNFα or Ro, and the hash symbol (#) indicates a significant difference compared to cells treated with TNFα only (p < 0.05). The results are representative for all three cell lines and all analyses were performed in triplicates.