A class of (thio)chromenone derivatives has been identified as suitable ligands for uPAR, a glycoprotein with a prognostic value in a large number of human cancers. The (thio)chromenone agents actively inhibited the binding of uPAR to uPA with a binding affinity of 18.6 nM, reducing cell migration in the wound healing assay by up to 40% without apparent cell motility. The discovery of an uPAR-targeting fluorescent probe was also made in this study that can selectively bind to the membrane uPAR, providing valuable molecular insights into the role of uPAR in cancer metastasis. This study should serve as a basis for the development of new uPAR-targeting agents that can control the metastatic potential of cancer cells with minimal cytotoxicity.
