Noninvasive Bioluminescence Imaging of Matrix Metalloproteinase-14 Activity in Lung Cancer Using a Membrane-Bound Biosensor.

Matrix metalloproteinase-14 (MMP-14) plays a crucial role in the cancer migration and metastasis by guiding the extracellular matrix remodeling and cell motility. Despite increasing efforts have been taken to develop methodology for measuring MMP-14 expression, there is a lack of tools capable of monitoring the MMP-14 dynamic activity with high temporal and spatial resolution in living cells and animals. Here, we describe the design of Gaussia luciferase (Gluc)-based membrane-bound biosensor for efficient visualization of MMP-14 activity. The epidermal growth factor (EGF) induced significant luciferase changes in the biosensor-transfected lung cancer cells. Deletion of the transmembrane domain in the mutant biosensor or treatment with an MMP-14 inhibitor, tissue inhibitor of metalloproteinase-2 (TIMP-2), relieved the EGF-induced luciferase activation, suggesting that MMP-14 functions at the cell surface to result in luciferase changes. Moreover, utilizing this biosensor, the bioluminescence signals activated by MMP-14 enabled clear visualization of MMP-14-positive lung tumors in animal models. Our results indicated this biosensor is an effective probe for quantitatively monitoring proteolytic activities in live cells and mouse models. These findings offer the general design of biosensors as an adaptable tool for studying various membrane-anchored proteases in biological models.