THE ROLE OF THROMBIN IN TUMOR-CELL METASTASIS

The relationship between malignancy and thrombosis and hemostasis has long been recognized but is poorly understood. The interaction of tumo r cells and the proteins and cells of coagulation is symbiotic and com plex. Selected cancers have been known to respond to antithrombotic an d anticoagulant therapies such as warfarin, heparin and, most recently , hirudin. The identification of the functional 'tethered ligand' thro mbin receptor on platelets, other cells and recently tumor cells has p rovided additional opportunities to examine and control the course of tumor proliferation. Thrombin, at concentrations which precede fibrin formation, is a potent inducer of tumor cell. expression of various in tegrin receptors and tumor cell adhesion to the matrix and other activ ated cells. New strategies based on specifically controlling the actio n of thrombin may be beneficial in arresting the proliferation of thes e cells.