Thromb Haemost 2013; 110(05): 1046-1054
DOI: 10.1160/TH13-02-0158
Cellular Proteolysis and Oncology
Schattauer GmbH

Cyr61 is a target for heparin in reducing MV3 melanoma cell adhesion and migration via the integrin VLA-4

Patrick Schmitz*
1   Department of Pharmacy, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
,
Ursula Gerber*
1   Department of Pharmacy, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
,
Norbert Schütze
2   Orthopedic Center for Musculoskeletal Research, University Würzburg, Würzburg, Germany
,
Eva Jüngel
3   Frankfurt University Hospital, Center of Surgery, Research Laboratory, Frankfurt am Main, Germany
,
Roman Blaheta
3   Frankfurt University Hospital, Center of Surgery, Research Laboratory, Frankfurt am Main, Germany
,
Annamaria Naggi
4   “G. Ronzoni” Institute for Chemical and Biochemical Research, Milano, Italy
,
Giangiacomo Torri
4   “G. Ronzoni” Institute for Chemical and Biochemical Research, Milano, Italy
,
Gerd Bendas
1   Department of Pharmacy, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Received: 21. Februar 2013

Accepted after major revision: 18. Juli 2013

Publikationsdatum:
01. Dezember 2017 (online)

Zoom Image

Summary

The integrin VLA-4 is important for the metastatic dissemination of melanoma cells. We could recently show that heparin can block VLA-4 binding, which contributes, next to blocking P-and L-selectin, to the understanding of antimetastatic activities of heparin. The matricellular ligand Cyr61, secreted by numerous tumours, is responsible for increased tumourigenicity and metastasis. This has been attributed to Cyr61 binding to, and thus activating integrins. However, a VLA-4/Cyr61 axis has not yet been reported. Since Cyr61 possesses heparin binding capabilities, Cyr61 can be supposed as potential target for heparin to indirectly interfere with integrin functions. The present in vitro studies address (i) the existence of a Cyr61/VLA-4 axis and (ii) the functional relevance of heparin interference via Cyr61. The C-terminal module III of Cyr61 could be exposed as nanomolar affine binding site for VLA-4. A shRNA-based knockdown of Cyr61 in MV3 human melanoma cells reduced VLA-4-mediated cell binding to VCAM-1, migration on fibronectin, and integrin signalling functions significantly. Using a biosensor approach we provide insight into heparin interference with this process. The low-molecular-weight heparin tinzaparin, but not the pentasaccharide fondaparinux, binds module IV of Cyr61 with micromolar affinity. But tinzaparin cannot interfere with Cyr61 accumulation onto syndecan-4, indicating different Cyr61 binding sites for heparin and other GAGs. Nonetheless, tinzaparin affects the VLA-4 binding and signalling functions selectively via Cyr61 already at very low concentration most likely by blocking the cellular secreted free Cyr61. This study emphasises Cyr61 as promising, and hitherto not considered target for heparin to selectively influence integrin functions.

* These authors contributed equally.