Appearance of angiotensin II expression in non-basal epithelial cells is an early feature of malignant change in human prostate

Background: Despite increasing interest in the renin-angiotensin system in cancer, little is known about angiotensin II (Ang II) expression in human prostate tumors. Methods: Using immunohistochemistry, we examined Ang II expression in prostate cancer (Gleason grades 2–5), benign prostatic hyperplasia (BPH), and high-grade prostatic intraepithelial neoplasia (HGPIN). Results: Ang II was present in proliferating neoplastic cells in HGPIN, in malignant cells in all grades of prostate cancer examined, in basal but not luminal epithelial cells in BPH, and in the cytoplasm of LNCaP, DU145, and PC3 prostate cancer cells. Conclusions: The data establishes the presence of Ang II in pre-malignant and malignant prostate cells, suggests Ang II staining in non-basal epithelial cells is an early sign of malignant change, and supports suggestions that HGPIN and malignant prostate cells both arise from transformed basal cells. Using immunohistochemistry we examined Ang II expression in proliferative disorders of the prostate and concluded that Ang II staining in non-basal epithelial cells is evidence of early malignant change.