FIG. 7.

MDR1 expression is correlated with APE1 levels in normal lung and NSCLC tissues. (A) Western analysis of APE1, AcAPE1, and MDR1 levels in cell extracts of various lung cancer cell lines. α-Tubulin was used as the loading control. (B) Real-time RT-PCR analysis of APE1 and MDR1 mRNA expression levels in 15 NSCLC specimens and proximal normal lung tissues as described in Materials and Methods. The level of APE1 mRNA was expressed relative to the level in normal lung tissue of patient 1n,which was normalized to 1. n, normal lung tissues; c, NSCLC tissues. The bar graph shows the averages ± standard deviations for three independent experiments performed in duplicates. (C) Correlation between APE1 and MDR1 expression levels in both normal and NSCLC samples together (left) (r = 0.581; P = 0.0005) and in NSCLC samples (right) (r = 0.558; P = 0.03).