LAUSR

The majority of cancer patients die of metastasis rather than primary tumors, and most patients may have already completed the cryptic metastatic process at the time of diagnosis, making them intractable for therapeutic intervention. The urokinase-type plasminogen activator (uPA) system has been proved to drive cancer metastasis. However, current blocking agents such as uPA inhibitors or antibodies were far from satisfactory due to poor pharmacokinetics and especially have to face multiplex mechanisms of metastasis. Herein, an effective strategy was proposed to develop a uPA-scavenger macrophage (uPAR-MΦ), followed by loading chemotherapeutics with nanoparticles (GEM@PLGA) to confront cancer metastasis. Interestingly, significant elimination of uPA by uPAR-MΦ is demonstrated by transwell analysis on tumor cells in vitro and enzyme-linked immunosorbent assay (ELISA) detection in peripheral blood of mice with metastatic tumors, contributing to significant inhibition of migration of tumor cells and occurrence of metastatic tumor lesions in mice. Moreover, uPAR-MΦ loaded with GEM@PLGA showed a robust anti-metastasis effect and significantly prolonged survival in 4T1-tumor bearing mice models. Our work provided a novel living drug platform for realizing a potent treatment strategy to patients suffering from cancer metastasis, which can be further expanded to handle other tumor metastasis markers mediating cancer metastasis. This article is protected by copyright. All rights reserved.