Angiopoietin 2 expression is related to histological grade, vascular density, metastases, and outcome in prostate cancer

Abstract

Background: In several malignant tissues, the angiopoietins are principal regulators of vascular growth and regression, but in normal prostate and prostate tumors the role of the angiopoietins is unknown.

Methods: Angiopoietin (ang) 1 and 2 were immunolocalized in TUR-diagnosed prostate tumors with long follow-up and the expression was related to vascular density and clinicopathological variables.

Results: Ang 1 was strongly expressed in the basal epithelial cell layer in non-malignant tissue, whereas tumors had lower levels localized to the epithelial cells. A weak ang 2 immunoreaction was observed in non-malignant tissue and in low to intermediate Gleason score (GS) tumors, with a similar expression pattern. However, most high GS tumors showed an intense ang 2 staining. Ang 2 was significantly correlated to GS, density of endoglin stained blood vessels, metastases, and to cancer specific survival.

Conclusions: We conclude that ang 2 probably is an important regulator of angiogenesis in prostate cancer.