Antithrombin is an important inhibitor of the coagulation cascade, but it can also serve as an anti-inflammatory, antiangiogenic, antiviral, and antiapoptotic protein. A role for antithrombin in modulating tumor cell invasion and migration has been demonstrated here. U87-MG, A549, and HT29 cell surfaces. A central loop and heparin-binding domain are required for the inhibitory process to occur, and antithrombin must be activated by heparin. This study has revealed a novel mechanism of inhibition for enteropeptidase, cleavage of antithrombin, in turn, has resulted in a molecule with antiangiogenic properties that reduces the formation of vascular endothelium.
