Figure 5.

Decreased cell death, but not increased cell proliferation, is associated with prostatic enlargement. A: Quantification of Ki-67 positivity, used herein as an indicator of proliferation, demonstrates no significant increase in the percentage of proliferating cells in the testosterone and estradiol (T+E) cohort of mice. Data from 12- and 15-week time points were combined for increased statistical power (5 to 10 fields quantified per mouse). Representative images of Ki-67 immunostaining (each from the dorsal lobe) are shown. Red arrows denote Ki-67⁺ cells. B: Immunofluorescence analyses of Ki-67 positivity (green) in both CK5-positive basal epithelial cells (white) and CK8-positive luminal epithelial cells (red) demonstrate no change in the population of epithelial cells undergoing cell proliferation in the T+E versus testosterone alone (T-control) mice. Nuclei are counterstained with DAPI in blue. Yellow arrows denote Ki-67⁺ cells. Representative images of immunostaining are shown. C: Quantification of cell death using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining via immunohistochemistry (5 to 10 fields quantified per mouse) demonstrates a significant reduction in cell death on prostatic enlargement. eSlide Manager software version 12.1.0.5029 (Aperio) was used to count positive cells using a Positive Nuclear Algorithm optimized on test and control slides (dotted boxes shown at higher magnification in the right panels). Representative images of immunostaining are shown. Blue cells are negative for TUNEL, yellow cells are 1+ positivity, orange cells are 2+ positivity, and maroon cells are 3+ positivity (red arrows denote 3+ TUNEL⁺ cell nuclei). n = 4 mice (A); n = 2 mice (C). ^∗P < 0.05 versus T control. Original magnification, ×40 (A–C).