Translocating a High-Affinity Designer TIMP-1 to the Cell Membrane for Total Renal Carcinoma Inhibition: Putting the Prion Protein to Good Use.

embrane ype -atrix etalloroteinase (MT1-MMP) and umor necrosis factor (TNF-α)-onverting nzyme (TACE) are prominent membrane-anchored metalloproteinases that regulate the turnover of extracellular matrix (ECM) components and bioactive molecules required for cancer proliferation. In this study, we describe a novel approach that would allow tissue inhibitor of metalloproteinase 1 (TIMP-1), the endogenous inhibitor of the matrix metalloproteinases (MMPs), to be translocated to the cell membrane for simultaneous MT1-MMP/TACE inhibition. We achieve this by fusing T1, a designer TIMP-1 with superb affinities for MT1-MMP and TACE, to the glycosyl-phosphatidyl inositol anchor of prions to create a membrane-tethered, broad-spectrum inhibitor, named T1, that colocalizes with MT1-MMP and TACE on the cell surface. Transduction of T1 in human fibrosarcoma cells results not only in a substantial reduction in gelatinolytic and TNF-α/heparin binding epithelial growth factor shedding activities but also in a loss of tubulogenic capability in three-dimensional matrices. In renal carcinoma, T1 triggers cellular senescence and disrupts MMP-mediated proteolysis of ECM components such as fibronectin and collagen I, leading to an impairment in cell motility and survival under both and conditions. Taken together, our findings may provide a new perspective in TIMP targeting that could be exploited to halt metastatic renal carcinoma progression.