In vitro evaluation of chemopreventive agents using cultured human prostate epithelial cells.

The effects of nine potential cancer chemopreventive agents on cell growth or clonogenic survival were evaluated in normal human prostate epithelial cells, an immortalized but non-tumorigenic human prostate epithelial cell line (267B1), a human benign prostatic hyperplasia (BPH) cell line (BRF-55T), and a human prostate cancer cell line (267B1/Ki-ras). Of the nine agents tested, 9-cis retinoic acid, liarozole fumarate, phenylenebis(methylene)-selenocyanate (p-XSC), and L-selenomethionine demonstrated much stronger growth inhibitory effects on prostate cancer cells than on the normal prostate epithelial cells, suggesting that these agents may be useful as prostate cancer chemopreventive agents. 9-cis retinoic acid, genistein, liarozole fumarate, p-XSC, L-selenomethionine and vitamin E also showed much stronger growth inhibitory effects on BRF-55T cells than on the normal prostate epithelial cells, indicating that these agents may also be useful for the prevention and treatment of BPH. Difluoromethylornithine (DFMO), DHEA analogue 8354 (fluasterone), and oltipraz did not show strong inhibitory effects on the growth or survival of normal prostate epithelial cells, 267B1 or 267B1/Ki-ras cells, suggesting that these agents may not be effective as prostate cancer preventive or therapeutic agents.