Figure 1

Relative mRNA levels of PXR in esophageal epithelium as determined by quantitative Real-Time PCR. (A) PXR levels in columnar epithelium (CE) are normalized to adjacent squamous epithelium (Sq) using 2^(-ΔΔCt) method [23] and are plotted for each of 21 Barrett's esophagus (BE) patients. Error bars express a range which is a result of incorporating the standard deviation into the calculation. The mean of this population renders a strong significant increase of PXR mRNA levels in CE compared to Sq of BE patients (P < 0.001). (B) PXR mRNA levels are calculated using 2^(-ΔCt) to show interindividual differences in PXR expression in RE, BE, and EAC patients and plotted on a log scale. Levels in Sq from patients with reflux esophagitis, and patients with BE are lower than in CE derived from the esophagus of BE patients (P = 0.003 and P < 0.001 respectively). mRNA levels in tissue from adenocarcinoma patients did not differ statistically from CE of BE patients, but was significantly higher than all Sq tissues. The detection limit for this assay was 0.0001.