Figure 2

Mean RNA expression levels for pirin assessed by quantitative PCR in human bronchial epithelial (HBE) cells exposed to varying concentrations of cigarette smoke extract (CSE) over time. RNA was extracted from HBE cells after exposure to 10% and 100% CSE and pirin RNA levels were quantified relative to the control gene GAPDH by real-time quantitative PCR by TaqMan. Each data point was generated from triplicate wells; and a total of three separate data points were obtained for each condition at each time point. The ordinate represents the fold change in pirin expression in samples exposed to 10% and 100% CSE over time relative to the background pirin expression level in cells cultured in the absence of CSE.