Bioluminescence Imaging of Urokinase-Type Plasminogen Activator Activity in Vitro and in Tumors

Urokinase-type plasminogen activator (uPA) is a cell-secreted serine protease and plays a significant role in numerous biological processes. Overexpression of uPA has been proved to be relevant to some malignant tumors as well as poor prognosis. However, bioluminescence (BL) probes for selectively sensing uPA activity have not been reported up to now. Herein, we designed a BL probe, GGR-AmLuc, to detect uPA in vitro and sense uPA both inside cells and in tumors. In vitro studies demonstrated that GGR-AmLuc was able to selectively detect uPA with a limit of detection (LOD) of 1.37 mu g/L. Moreover, GGR-AmLuc was successfully applied to image uPA in living subjects with excellent sensitivity. We anticipate that probe GGR-AmLuc could be applied for highly sensitive diagnosis of cancers overexpressing uPA and provide guidance for cancer treatment in the near future.