Figure 5
From: Darpp-32 and t-Darpp are differentially expressed in normal and malignant mouse mammary tissue
Tumor growth in PyMT/Ppp1r1b+/+and PyMT/Ppp1r1b-/-mice. (A) The age at which tumors first appeared (tumor volume 100–300 mm3) was recorded for wild-type (PyMT/Ppp1r1b+/+) and knockout (PyMT/Ppp1r1b-/-) tumor mice (n = 14 per group). Individual ages and the mean age at appearance (±standard error of the mean) are shown. (B) Kaplan–Meier survival plot showing the age at which mice were euthanized because of extensive tumor burden (maximum tumor volume >1500 mm3). (C-D) Mice surviving to 20 weeks of age were euthanized and tumor volume was measured. (C) Total tumor volume in these mice was calculated as the sum of the individual tumor volumes for each mouse. (D) Maximum tumor volume was defined as the volume of the largest individual tumor per mouse (n = 8–12 per group); mean ± standard error of the mean, *p < 0.05. (E-F) Tumors were collected at 20 weeks of age, formalin-fixed, sectioned and immuno-stained for Ki67 and CD31. (E) Representative tumor sections and bar graph showing the mean (± standard error of the mean) number of Ki67-positive cells per field in 10 nonoverlapping fields from three tumors per group (25× magnification, scale bar = 50 μm). (F) Representative tumor sections and bar graph showing the mean (± standard error of the mean) microvessel density determined by counting the number of CD31-positive endothelial clusters (white arrows) in 10 nonoverlapping fields from three tumors per group (25× magnification, scale bar = 50 μm). (G) Number of PyMT-positive metastatic nodules in each lung analyzed at 20 weeks of age. Individual lung counts (n = 8 per group) and the mean (± standard error of the mean) for each genotype group are shown.