Effect of TNFα treatment on the mRNA expression of IL-8 and PBEF in A549 cells. A. A representative gel image of IL-8, PBEF and β-actin mRNA detections. After starving for serum overnight, A549 cells were stimulated with TNFα (15 ng/ml) for 4 h. Total cell RNA was reverse-transcribed, amplified by PCR using the gene specific primers (Table 1), separated by 1.5% agarose electrophoresis, and visualized with ethidium bromide. B. Quantitation of IL-8 and PBEF mRNA levels by densitometric analysis. Results from each group are presented as mean ± SD of 4 samples from two separate experiments. *p < 0.05 and **p < 0.01 vs 0 dosage of TNFα or control.