Figure 4

Concentration-dependent DEP-induced expression of IL-6 (A), IL-8 (B), COX-2 (C) and CYP1A1 (D) mRNA. Human bronchial epithelial BEAS-2B cells were exposed to increasing concentrations of DEPs (0-200 μg/ml) for 4 h. Relative quantification of cytokine mRNA levels was performed by QRT-PCR. Bars represent means ± SEM of fold increase relative to unexposed cells detected in separate experiments (n = 3). Experiments with very low concentrations (0.025, 0.05 and 0.1 μg/ml) were only repeated twice. * p < 0.05; exposed vs. unexposed cells.