Research Paper Volume 14, Issue 10 pp 4281—4304

Figure 1. AhR depletion increases liver tumorigenesis with aging. (A) Representative tumors developed by AhR+/+ and AhR−/− at the indicated ages. (B) Haematoxylin and Eosin staining of liver tumor sections from AhR+/+ and AhR−/− mice at 22 months of age. Note the abundance of pycnotic nuclei in AhR−/− tumors. (C) Quantification of the number of liver tumors in mice of both genotypes at two age intervals. (D) AhR mRNA levels in AhR+/+ livers at the indicated ages using RT-qPCR and the oligonucleotides indicated in Supplementary Table 1. (E) AhR protein levels were analyzed in liver extracts at the indicated ages by immunoblotting. β-Actin was used to normalize protein levels. (F) AhR+/+ mice were injected i.p. with 4 mg/kg FICZ and mRNA levels of the AhR canonical target gene Cyp1a1 were determined by RT-qPCR using the oligonucleotides indicated in Supplementary Table 1. (G) Liver progenitor cells were analyzed by FACS using antibodies against CD133-PE and EPCAM-APC. Distribution of cell subpopulations and gating from representative experiments are shown. (H) Bone marrow progenitor cells were analyzed by FACS using the markers CD44-FITC and Sca1-APC. Distribution of cell subpopulations and gating from representative experiments are shown. Gapdh was used to normalize target gene expression (△Ct) and 2^−△△Ct to calculate changes in mRNA levels with respect to wild type or untreated conditions. Data are shown as mean + SD (^*P < 0.05; ^**P < 0.01).