PrLZ, a Novel Prostate-Specific and Androgen-Responsive Gene of the TPD52 Family, Amplified in Chromosome 8q21.1 and Overexpressed in Human Prostate Cancer

We report a previously unrecognized prostate-specific protein, PrLZ (prostate leucine zipper), a new member of the Tumor Protein D52 (TPD52) family. The gene for PrLZ was localized at chromosome 8q21.1, a locus most frequently amplified in human prostate cancer. Multiple tissue analyses demonstrated PrLZ predominantly in the prostate gland. Although its expression was enhanced by androgens in androgen receptor-expressing cells, PrLZ was detected in all of the human prostate cancer cell lines, regardless of androgen receptor status. Monoclonal anti-PrLZ antibodies were produced and intense immunohistochemical staining of PrLZ was observed in prostate epithelial cells in intraepithelial neoplasia and prostate cancer, whereas lower-level staining was detected in normal and benign epithelial components of the prostate gland. As the only prostate-specific gene identified in the most frequently amplified genomic region in prostate cancer, PrLZ may be the link between chromosome 8q amplification and malignant transformation of the prostate epithelia.