1. ¹Department of Biochemistry, Norris Cotton Cancer Center, Dartmouth Medical School, Lebanon, NH 03756, USA
2. ²Department of Medicine, Norris Cotton Cancer Center, Dartmouth Medical School, Lebanon, NH 03756, USA
3. ³Department of Pathology, Haartman Institute, University of Helsinki and Helsinki University Central Hospital, Helsinki, FIN-00014, Finland

Correspondence: CE Brinckerhoff, Norris Cotton Cancer Center, Dartmouth Medical School, Department of Medicine, 1 Medical Center Drive, Rubin Building, HB#7936, Lebanon, NH 03756, USA. E-mail: constance.e.brinckerhoff@dartmouth.edu

Received 7 October 2004; Accepted 19 October 2004; Published online 13 December 2004.

Abstract

Metastatic renal cell carcinoma (RCC) resulting from the hereditary loss of the von Hippel–Lindau (VHL) tumor suppressor gene is the leading cause of death in VHL patients due to the deleterious effects of the metastatic tumor(s). VHL functions in the destruction of the alpha subunits of the heterodimeric transcription factor, hypoxia-inducible factor (HIF-1 and HIF-2), in normoxic conditions. When VHL function is lost, HIF- protein is stabilized, and target hypoxia-inducible genes are transcribed. The process of tumor invasion and metastasis involves the destruction of the extracellular matrix, which is accomplished primarily by the matrix metalloproteinase (MMP) family of enzymes. Here, we describe a connection between the loss of VHL tumor suppressor function and the upregulation of membrane type-1 MMP (MT1-MMP) gene expression and protein. Specifically, MT1-MMP is upregulated in VHL-/- RCC cells through an increase in gene transcription, which is mediated by the cooperative effects of the transcription factors, HIF-2 and Sp1. Further, we identify a functional HIF-binding site in the proximal promoter of MT1-MMP. To our knowledge, this is the first report to show direct regulation of MT1-MMP by HIF-2 and to provide a direct link between the loss of VHL tumor suppressor function and an increase in MMP gene and protein expression.