Taylor et al. BMC Cancer 2010, 10:541 http://www.biomedcentral.com/1471-2407/10/541 Page 6 of 12 Figure 1 Morphological changes in DLP of p27 deficient mice in the course of carcinogenesis. 1A: Dorso-lateral prostate of 6-month-old p27-/- mice. Note the glandular structures are covered by a single layer of prostate epithelial cells (PEC). Glands are surrounded by a thick layer of myoepithelial cells, stroma cells and collagen (arrows). H&E staining × 200. 1B: High grade PIN in a p27-/- mice treated with MNU and sacrificed at the age of 9 months. Hyperplastic and dysplastic PEC cover entire glands and form papillary and alveolar structures (arrows). The surrounding connective tissue stroma is very abundant (arrow had). H&E × 200. 1C: Ductal carcinoma of papillary type in DLP of a p27-/- animal treated with MNU and sacrificed at the age of 10 months. Note, tumor cells occupy the entire glands lumen. H&E × 200. 1D: Infiltrative prostate carcinoma in a p27-/- animal sacrificed at the age of 12 months. Tumor cells infiltrate the surrounding stroma (arrows). H&E × 200. 1E: Pituitary tumor in a p27-/- mice sacrificed at the age of 10 months. H&E × 200. 1F: Intestinal carcinoma in a p27-/- mice sacrificed at the age of 9 months. Note tumor cell infiltration in the surrounding stroma (arrow). H&E × 200. 1G: RARa expression in DLP of a 6-month-old p27+/- mice. RARa was detected by anti-RARa antibody (SC-251) and ABC kit. The receptor is expressed in papillary structures (arrow) and in the basal layer of epithelial cells. The slide is counterstained by hematoxylin × 200. 1H: RXRa expression in PIN of p27-/- 9-month-old mice. Note that most epithelial cells express RXRa receptor (arrow). The slide is counterstained by hematoxylin × 200.