Estrogen receptor β expression in human prostate tissue

Estrogen receptor subtype β (ERβ) is highly expressed in rat prostate epithelium, but its presence in human prostate needs to be confirmed. Here we investigated the expression of ERβ in five benign (normal and/or hyperplastic) and 10 malignant (Gleasons’ score 2–7) prostate tissue specimens using immunohistochemistry. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue sections, using a commercially available ERβ polyclonal antibody developed against the C-terminal amino acid residue. Nuclear ERβ expression was found in the nuclei of glandular epithelium of benign prostate tissue specimens; faint nuclear ERβ positivity was also present in a few stromal cells around normal epithelium. Nuclear ERβ specific immunostaining was undetectable in all prostate cancer sections.