Tissue and in Carcinoma Two Differentially Expressed Genes in Normal Human Prostate

Alterations in transcriptional control may contribute directly to can. inogenesis. Using the differential display technique in prostate cancer cells compared to normal prostate epithelial cells, we identified a down-regu lated gene and an up-regulated gene in cancer cells. The down-regulated gene encodes human epithelial tropomyosin (TMel), a member of the family of actin filament-binding proteins. The up-regulated gene encodes cytochrome c oxidase subunit Vic (COSVIc), a protein of the respiration chain in the mitochondria! inner membrane. The differential display pattern was confirmed by Northern hybridization in both prostate tissue and cell lines. In situ hybridization of malignant prostate epithelial tissue using a digoxigenin-labeled antisense riboprobe detected strong staining for niKN \ of COSYIc, as opposed to very weak staining in normal prostate epithelium. The expression pattern of COSVIc may be a useful marker for studying the alteration of energy metabolism in cancer cells and for the diagnosis of prostate cancer.