Document Type

Article

Publication Date

2-2017

Publication Title

Clinical & Experimental Metastasis

Volume

34

Issue

2

First Page

155

Last Page

169

DOI

10.1007/s10585-017-9837-y

Abstract

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a basic carboxypeptidase zymogen present in blood plasma. Proteolytic activation of TAFI by thrombin, thrombin in complex with the endothelial cell cofactor thrombomodulin, or plasmin results in an enzyme (TAFIa) that removes carboxyl-terminal lysine residues from protein and peptide substrates, including cell-surface plasminogen receptors. TAFIa is therefore capable of inhibiting plasminogen activation in the pericellular milieu. Since plasminogen activation has been linked to angiogenesis, TAFIa could therefore have anti-angiogenic properties, and indeed TAFIa has been shown to inhibit endothelial tube formation in a fibrin matrix. In this study, the TAFI pathway was manipulated by providing exogenous TAFI or TAFIa or by adding a potent and specific inhibitor of TAFIa. We found that TAFIa elicited a series of anti-angiogenic responses by endothelial cells, including decreased endothelial cell proliferation, cell invasion, cell migration, tube formation, and collagen degradation. Moreover, TAFIa decreased tube formation and proteolysis in endothelial cell culture grown alone and in co-culture with breast cancer cell lines. In accordance with these findings, inhibition of TAFIa increased secretion of matrix metalloprotease proenzymes by endothelial and breast cancer cells. Finally, treatment of endothelial cells with TAFIa significantly inhibited plasminogen activation. Taken together our results suggest a novel role for TAFI in inhibiting tumour angiogenic behaviors in breast cancer.

Comments

The online version of this article (doi:10.1007/s10585-017-9837-y) contains supplementary material, which is available to authorized users.

Available for download on Sunday, January 01, 2119

Included in

Biology Commons

Share

COinS