Tetranectin is a homotrimeric glycoprotein present in plasma and various tissue locations that binds to calcium, heparin, and plasminogen kringle 4. Tetranectin may play a prominent role in tissue remodeling as well as in the regulation of proteolytic processes via its binding and indirect activation of plasminogen. Tetranectin is found in the extracellular matrix (ECM) of certain carcinomas, but is not present in the ECM of normal tissues. Extracellular proteolysis is an important factor in the ability of malignant cells to penetrate normal tissues and metastasize. Decreased plasma tetranectin or increased tetranectin in stroma of cancers correlates with cancer progression and a grim prognosis. Tetranectin may also influence cancer growth by altering activities of plasminogen or the plasminogen fragment, angiostatin which inhibits tumor cell proliferation.
