Fig. 1.

NR gene expression signature in lung cancer cell lines. A, Unsupervised cluster analysis for 55 lung cell lines using the NR QPCR mRNA expression data. Colors depict immortalized and normal HBEC (green), SCLC (red), and NSCLC (blue) cell lines. B, Heat map of relative NR expression in lung cancer cell lines. Expression values for each NR were normalized to the average receptor value (arbitrarily set to 1) obtained from the five normal HBEC cell lines. Red and green colors represent values that were higher or lower, respectively, than the average value observed in the normal HBEC. The horizontal axis shows unsupervised clustering of 47 NRs (including the alternative splice variants for PPARγ and PPARδ), and the vertical axis displays the 55 lung cell lines ordered based on their pathological classification. ME, Mesothelioma; BA, bronchioalveolar. Constitutive androstane receptor, farnesoid X receptor, and HNF4α were not included due to their low expression (Ct > 34). The scale represents log 2 ratio of the normalized NR expression values.