Cloning and characterization of the prostate-specific membrane antigen promoter

Prostate-specific membrane antigen (PSMA) is-a protein that is expressed pr edominantly in normal prostate epithelial cells and in most adenocarcinomas of the prostate (Cap) and in virtually all Cap metastases. In this article we describe the cloning or a 2-kb human genomic DNA fragment containing th e 5' upstream untranslated region of the PSMA gene and present evidence tha t it provides promoter activity. When the DNA fragment was cloned into tran sient expression vectors to examine promoter activity, the vectors were fun ctional in promoting expression in several prostate and nonprostate cell li nes in transient transfection assays. A 614-bp fragment derived from the 3' end of the 2-kb fragment may represent the minimal PSMA promoter as determ ined by deletion mutagenesis. The 2-kb fragment compared with the 614-bp fr agment provided higher expression levels when using prostate-derived cell l ines (DU 145 and LNCaP). the increased transcription using the 2-kb fragmen t was not as great in non-prostate cell lines. Little or no transcription o ver basal levels was seen with a 232-bp promoter fragment. When the concent ration of dihydrotestosterone was depleted or supplemented in the growth me dium, no significant effect was seen on PSMA-promoted transient expression in LNCaP cells, a prostate cell line. Published 1999 Wiley-Liss, Inc.dagger .