Molecular analysis of the prostate-specific antigen upstream gene enhancer

BACKGROUND: Our objective was to identify factors other than androgen receptor that bind to and regulate the prostate-specific antigen (PSA) upstream gene enhancer (PSE). METHODS: DNAse I footprinting and electromobility shift assays (EMSA) were performed over the PSE using lysates from PSA-producing cell lines, LNCaP and LAPC4, and nonproducing PSA cell lines, PC-3 cells, U937 monocytes, and Namalwa B cells. Mutational analysis and transient transfection assays were used to determine the contributions made by different elements towards the regulation of the enhancer. RESULTS: Three distinct regions surrounding androgen response elements of the PSE were found to bind unknown ubiquitous and cell type-specific proteins. These regions, when mutated in a PSE reporter construct, were shown to be required for maximal activation in LNCaP cells. CONCLUSIONS: These results correlate unknown sequence-specific DNA binding proteins with androgen-mediated regulation of a prostate-specific gene, thus providing further insight into the mechanism of PSA gene expression.