Fig. 3.

AHR hyper-activation increases expression of stem cell-associated genes. Hs578T cells were treated with vehicle or 0.5 μM FICZ for 48 hours, sorted into ALDH^high and ALDH^low cell populations, and then assayed by RT-qPCR for the relative levels of the eight stem cell-associated genes indicated. Gene expression was then normalized to Gapdh levels and fold-change from vehicle-treated ALDH^low or ALDH^high cells was calculated. Data from nine independent experiments are presented as the mean fold-change ± standard error for all genes except for Cyp1a1, in which six independent experiments are presented. In all cases, statistical significance was determined with the Wilcoxon rank sum test to determine if the distributions of results, relative to 1 as the standard (represented by the dotted line on each graph), are different between the comparison groups. Asterisks indicate a significant increase in the mRNA fold-change, *P <0.05, **P <0.01, ***P <0.005. (a) Expression levels of stem cell-associated genes were normalized to expression levels in vehicle-treated ALDH^low cells and the distribution of outcomes from vehicle-treated ALDH^high versus vehicle-treated ALDH^low cells compared. (b) Stem cell-associated gene expression levels were normalized to expression levels in vehicle-treated ALDH^low cells and the distribution of outcomes from vehicle-treated ALDH^low versus FICZ-treated ALDH^low cells was compared. (c) Stem cell-associated gene expression levels were normalized to expression levels in vehicle-treated ALDH^high cells and the distribution of outcomes from vehicle-treated ALDH^high versus FICZ-treated ALDH^high cells was compared