Prostate growth factor in the extracts of benign prostatic hypertrophy. Partial purification and physicochemical characterization.

The biochemical and physicochemical properties of prostate growth factor (PGF) in the extracts of benign prostatic hypertrophy (BPH) were investigated. The PGF activity stimulating the proliferations of fibroblasts (mouse 3T3 and human BUD-8 cells) was detected predominantly in BPH prostate, and also in normal human prostates and well-differentiated adenocarcinoma prostates. No significant correlation between PGF contents and BPH tissue weight or histological differences (fibromuscular or glandular type) was detected. Gel filtration and isoelectric focusing indicated that partially purified factor(s) by ion exchange column chromatography had a multimolecular form comprising three active components (80,000, 43,000 and 10,000 daltons) and acidic isoelectric points (pH 4.0, 4.3, and 6.0). The activity was susceptible to heat treatment at 80 degrees C for 10 min, and to trypsin, but the factor was devoid of esteropeptidase activity. Subcellular fractionation located the entire activity in cytosol fraction.