Figure 6

Enzalutamide inhibits estrogen-stimulated growth of MCF7 tumors as effectively as tamoxifen. MCF7-TGL cells stably expressing luciferase were implanted orthotopically in the mammary gland of ovariectomized female nude mice. All mice had an estradiol (E2) pellet implanted subcutaneously and were given either control chow (E2), control chow plus a tamoxifen pellet implanted subcutaneously (E2 + Tam) or chow containing 50 mg/kg enzalutamide (E2 + Enza). The tumor burden was measured by whole-body luminescence. (A) Mean total flux. Mice were matched on day -3 and treatment began on day 0 (arrow). *P < 0.05, analysis of variance (ANOVA) with Bonferroni’s multiple comparison test correction. (B) The total luminescent flux is shown for individual mice on the day of matching (day -3) and of final imaging (day 11). *P < 0.05, ANOVA with Bonferroni’s multiple comparison test correction. (C) Images of luminescent signal in the two treatment groups at time of matching (day -3) and the final day of imaging (day 11). (D) Mice were injected with bromodeoxyuridine (BrdU) 2 hours prior to sacrifice and immunohistochemistry for BrdU was performed on tumor sections and quantified using imageJ (National Institutes of Health, Bethesda, MD, USA). Representative images of BrdU staining (left, 400× magnification) and quantification (right). **P < 0.01 for E2 versus E2 + Tam, ***P < 0.001 for E2 versus E2 + Enza, ANOVA with Bonferroni’s multiple comparison test correction.