ERα localizes to extranuclear sites in E2- and RAL-induced T47D:A18/PKCα regressing tumors. A. Tissue sections were immunostained as described in materials and methods. Images are representative photographs of immunostained tumor sections. Sections were costained for ERα (green) and nuclei (blue). Scale bar = 20 μm. All images were acquired and processed using parameters described in materials and methods. PKCα, T47D:A18/PKCα; neo, T47D:A18/neo. B. Quantification of ERα localization in tumor sections. At least three fields from each tumor were counted. T47D:A18/neo is represented by two individual tumors. Bars representing T47D:A18/PKCα tumors show the mean (± SEM) of three individual tumors. ***, P < 0.001 compared to PKCα NT, TAM and RAL W/D by two-way ANOVA. C. Expression of ERα in whole cell tumor lysates. Molecular weights of ERα and β-actin are 67 kDa and 42 kDa, respectively. Values represent β-actin-normalized ERα expression relative to T47D:A18/neo E2-treated tumors.