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Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that contribute to pathological conditions associated with angiogenesis and tumor invasion. MMP-2 is highly expressed in human prostate cancer cells, and plays multiple critical roles in the neoplastic process, including facilitation of neoangiogenesis and formation of distal metastases. We have previously demonstrated that androgen induces MMP-2 expression in human prostate cancer cells (Liao et al. Endocrinology 2003; 144:1656). In this study, we sought to identify the androgen responsive elements (AREs) in MMP-2 promoter. We utilized a series of 5’-deletional MMP-2 gene reporter constructs to determine which fragment of the promoter is required for androgen induction of MMP-2 gene expression in prostate cancer LNCaP cells. A luciferase reporter gene was cloned into the downstream of the wild-type or mutant promoters. In addition, a chromatin-immunoprecipitation (ChIP) assay and the point mutagenesis approach were performed to confirm the identity or the interaction of androgen receptor with the element identified. Two sites (ARE-like 1 and ARE-like 2) were identified by the 5’-deletional MMP-2 gene reporter assay. Deletion of the ARE-like 1 or 2 site resulted in more than 70% reduction of androgen-stimulated reporter activity compared to the wild-type promoter. Deletion of both of the sites almost diminished the androgen response of the promoter. Site-specific mutagenesis analysis demonstrated that the two sites are responsible for androgen-stimulated reporter activity. Moreover, ChIP assay confirmed the interaction of the AR with the two sites after androgen treatment in LNCaP cells. Finally, AR binding to these two ARE-like sites was further confirmed by an EMSA assay. Our conclusion is that androgen regulates MMP-2 expression in prostate cancer cells via two pivotal ARE elements in the promoter region of MMP-2 gene. Acknowledgements: This study was supported by the KU William L.Valk Endowment, and grants from Kansas Mason’s Foundation and Lied Foundation.

[Proc Amer Assoc Cancer Res, Volume 46, 2005]