ERβ treatment after castration induces a second wave of apoptosis in castrate-resistant cells, including basal, luminal and intermediate cells.

<p>(<b>A</b>) Time course of total levels of prostatic apoptosis after 14 days of Cx followed sequentially by 3 days of vehicle (circles) or 8β-VE2 (triangles). Following treatment, groups are coloured green (vehicle) or red (8β-VE2) for clarity (n = 7/group). Representative micrographs show basal cell apoptosis (black arrows indicate apoptag⁺ staining) in 8β-VE2 treated tissues that is absent in vehicle controls. Breakdown of apoptotic levels in individual cell types following sequential treatment (<b>B–D</b>). (<b>B</b>) Stereological analysis (n≥7/group) showing levels of apoptosis in individual cell types in the prostates of mice treated with 14 day Cx +3 day vehicle (14dCx+3dV) or 14 day Cx +3 day 8β-VE2 (14dCx+3dβ). (<b>C</b>) Representative micrograph of immunofluorescent dual labeling in mouse ventral prostate with CKHMW (basal cell marker, green) and CK18 (luminal cell marker, red) used to identify intermediate cells (dual stained in yellow and indicated by white arrow) for quantitation in sequentially treated tissues. (<b>D</b>) Relative numbers of intermediate cells following 14 days of Cx and 3 days of vehicle (grey bars) or 8β-VE2 (open bars) (n≥5/group). (nd; non-detectable, <i>*P</i>&lt;0.05, <i>**P</i>&lt;0.01, ***<i>P</i>&lt;0.005 by Mann Whitney test (B) or students t-test (D)). (Scale A = 20 µm, C = 10 µm).