Amino-terminal fragments of laminin γ2 chain retract vascular endothelial cells and increase vascular permeability
Article first published online: 7 JAN 2014
© 2013 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Volume 105, Issue 2, pages 168–175, February 2014
How to Cite
Cancer Sci 105 (2014) 168–175
- Issue published online: 10 FEB 2014
- Article first published online: 7 JAN 2014
- Accepted manuscript online: 15 NOV 2013 11:45AM EST
- Manuscript Accepted: 11 NOV 2013
- Manuscript Revised: 2 NOV 2013
- Manuscript Received: 1 OCT 2013
- Ministry of Education, Culture, Sports, Science and Technology of Japan. Grant Numbers: 23112517, 23300351
- Laminin γ2 chain;
- tumor invasion;
- vascular endothelial cells;
- vascular permeability
Laminin γ2 (Lmγ2) chain, a subunit of laminin-332, is a typical molecular marker of invading cancer cells, and its expression correlates with poor prognosis of cancer patients. It was previously found that forced expression of Lmγ2 in cancer cells promotes their invasive growth in nude mice. However, the mechanism of the tumor-promoting activity of Lmγ2 remains unknown. Here we investigated the interaction between Lmγ2 and vascular endothelial cells. When treated with an N-terminal proteolytic fragment of γ2 (γ2pf), HUVECs became markedly retracted or shrunken. The overexpression of Lmγ2 or treatment with γ2pf stimulated T-24 bladder carcinoma cells to invade into the HUVEC monolayer and enhanced their transendothelial migration in vitro. Moreover, γ2pf increased endothelial permeability in vitro and in vivo. As the possible mechanisms, γ2pf activated ERK and p38 MAPK but inactivated Akt in HUVECs. Such effects of γ2pf led to prominent actin stress fiber formation in HUVECs, which was blocked by a ROCK inhibitor. In addition, γ2pf induced delocalization of VE-cadherin and β-catenin from the intercellular junction. As possible receptors, γ2pf interacted with heparan sulfate proteoglycans on the surface of HUVECs. Moreover, we localized the active site of γ2pf to the N-terminal epidermal growth factor-like repeat. These data suggest that the interaction between γ2pf and heparan sulfate proteoglycans induces cytoskeletal changes of endothelial cells, leading to the loss of endothelial barrier function and the enhanced transendothelial migration of cancer cells. These activities of Lmγ2 seem to support the aberrant growth of cancer cells.