Growth factors in benign prostatic hyperplasia (BPH) and prostate carcinoma

Abstract

It has been stated that, although steroid hormones are a necessary prerequisiste for prostate cell proliferation, cell division is not an inevitable consequence of the presence of hormones. The possibility that diffusible trophic factors play an important role in the normal and pathologic regulatory process within the prostate, offers a new and exciting research initiative. In order to better clarify the relationships between Epidermal growth factor (EGF), its receptor (EGFr) and steroid receptors at target tissue levels, we have demonstrated a statistically significant linear correlation between irEGF and nuclear androgen receptor (nAR) levels in human BPH tissue. Moreover we started an investigation to analyse the stroma-epithelium ratio and to verify EGF, EGFr, AR, DHT concentrations in the periurethral, central and peripheral zone of human BPH tissue. In all BPH zones the quantitative method of image analysis showed a higher percentage content of stroma than of epithelium. The highest levels of EGF, DHT and stroma content were present in the periurethral zone, where BPH begins. Both androgen and antiandrogen treatment enhance the proliferation rate of prostate cancer cell line LNCaP. After prolonged R1881 administration, a marked increase of EGF release was observed, completely blocked by the addition of OH-flutamide. The role of Transforming growth factor beta 1 (TGF beta1) in prostate cancer has been also demonstrated in prostate cancer tissue of patients submitted to radical prostatectomy.