Fig. 4.

Inhibition of MAPK pathways in CFBE cells has a similar effect on IL-8 mRNA stability as in IB3-1 cells. A: RNA was isolated from CFBE and HBE cells after treatment with actinomycin D (10 μg/ml) for the indicated time intervals. The remaining RNA was analyzed by quantitative real-time PCR and were normalized against that of control β-actin mRNA. The data (*P < 0.01) reflects averages of at least 3 independent experiments. B: IL-8 protein secreted by both cell types was analyzed by ELISA 16 h after transfection (P < 0.01). C: CFBE cells were treated with the chemical inhibitor SB-203580 (10 μM), U0126 (10 μM), or SP-600125 (10 μM). RNA was isolated from CFBE cells after actinomycin D (10 μg/ml) treatment for the indicated time intervals, and the remaining mRNA was analyzed by quantitative real-time PCR. The data reflect averages of at least 3 independent experiments (*P < 0.05 and **P > 0.05).