Immunohistochemical localization of TGFβ1, TGFβ2, and TGFβ3 in normal and malignant human prostate

BACKGROUND. Prostate cancer eventually becomes androgen-independent, suggesting that growth factors such as TGFβ1-3 may potentially contribute to prostate neoplasia. The pattern and level of TGFβ-3 protein expression in normal and malignant human prostate are unknown. METHODS. An immunohistochemical study was undertaken to analyze TGFβ1, TGFβ2, and TGFβ3 protein in malignant and adjacent normal prostates from 25 patients who had clinically localized prostate cancer. RESULTS. Normal prostate exhibited similar TGFβ1 immunostaining in stromal and epithelial cells, whereas TGFβ2 and TGFβ3 protein staining was greater in the epithelial relative to the stromal compartments. In malignancy, prostate epithelial cells had higher TGFβ1 and TGFβ2 immunostaining than either the surrounding stromal cells or their normal prostatic epithelial counterparts. Although TGFβ3 staining intensity was similar for both malignant and normal prostate epithelial cells, the pattern of staining switched from uniform apical to diffuse protein staining in malignant prostate glands. CONCLUSIONS. Prostate cancer was associated with alterations of TGFβ1, TGFβ2, and TGFβ3 expression by prostatic epithelial cells which may play a role in prostatic carcinogenesis.