Figure 3
Immunohistochemistry analysis of mammary intraepithelial neoplasia outgrowths (MIN-Os) treated with selective estrogen receptor modulator (SERM). (a) Estrogen receptor (ER)-positive status was assessed by immunohistochemisty. ER positivity was slightly increased in ospemifene-treated MIN-Os (P < 0.05) and significantly decreased by tamoxifen treatment (P = 0.0005). (b) The cell proliferation rate in SERM-treated MIN-Os was assessed by counting nuclei positive for the proliferation marker Ki-67 in a 40× field. Cell proliferation was in general decreased by the SERM treatments (P < 0.05 for ospemifene and P < 0.01 for tamoxifen). (c) SERM treatments slightly increased the averaged apoptotic cell number in the MIN-Os but the differences were not statistically significant (P = 0.198 for ospemifene and P = 0.4768 for tamoxifen).