TRANSFORMING GROWTH-FACTOR-BETA-1 EXPRESSION IN BENIGN AND MALIGNANT PROSTATIC TUMORS

The expression of transforming growth factor beta 1 (TGF-beta 1) in pr ostate specimens obtained from patients with benign prostatic hyperpla sia (BPH, n = 32) and prostate carcinoma (n = 66) was investigated usi ng Northern blot analysis and immunohistochemistry. Northern blot anal ysis revealed TGF-beta 1 message (2.5 kb) in virtually all of the samp les examined, reflecting the ubiquitous nature of this growth factor. No statistical difference was found between the levels of mRNA detecte d in benign and malignant tissues due, in part, to the inherent hetero geneity of prostate tissue. Immunohistochemical methods using an antib ody to native TGF-beta 1 revealed a novel pattern of immunoreactivity. Staining observed only in certain epithelial cells of benign glands w as associated with areas of infection rather than tumorigenesis. Inter estingly, intense staining was also seen in polymorphonuclear leukocyt es. No correlation was found with the mRNA results, suggesting that th is antibody is binding to TGF-beta 1 activated in response to infectio n rather than detecting sites of synthesis of latent TGF-beta 1. (C) 1 994 Wiley-Liss, Inc.