Expression of human prostatic acid phosphatase gene is regulated by upstream negative and positive elements

Human prostatic acid phosphatase (PAcP) is a prostate epithelium-specific differentiation antigen. To understand the regulation of expression of the PAcP gene, we studied the cis-regulatory elements of its promoter. A DNA fragment from -2899 to +87 base pairs (bp) of PAcP gene was fused to the chloramphenicol acetyltransferase (CAT) reporter gene and introduced into PC-3 and LNCaP human prostate cancer cells. The expression of the CAT gene driven by the PAcP promoter was assessed in transient expression assays. Sequential 5' deletions of the promoter were constructed and analyzed to reveal the positive and the negative regulatory elements that are involved in regulating the transcription of the PAcP gene. Our data showed that the proximal sequence -1305/+87 bp directs a high level of the CAT activity in both cell lines. Deletion of the region from -1305 to -779 resulted in approximately a 10- and three-fold decrease of the PAcP promoter activity in PC-3 and LNCaP cells, respectively. Interestingly, an inverse correlation of the CAT activity with the cell growth was observed when the reporter gene was driven by the -1305/+87 fragment, but not by the -779/+87 fragment. Two regions of transcriptional suppression were identified and located in positions from -2899 to -2583, and from -2583 to -1305 bp. Furthermore, the activity of the core promoter region from -779 to +87 bp can be activated by a SV-40 enhancer. The results, thus, clearly demonstrate the presence of positive and negative cis-elements in the promoter region of the PAcP gene.