Thromb Haemost 2014; 112(02): 402-411
DOI: 10.1160/TH13-11-0895
Cellular Proteolysis and Oncology
Schattauer GmbH

Potent and specific inhibition of the biological activity of the type-II transmembrane serine protease matriptase by the cyclic microprotein MCoTI-II

Kelly Gray
1   School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
,
Salma Elghadban
1   School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
,
Panumart Thongyoo
2   Biological and Biophysical Chemistry Section, Department of Chemistry, Imperial College London, UK
,
Kate A. Owen
1   School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
,
Roman Szabo
3   Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, NIH, Bethesda, Maryland, USA
,
Thomas H. Bugge
3   Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, NIH, Bethesda, Maryland, USA
,
Edward W. Tate
2   Biological and Biophysical Chemistry Section, Department of Chemistry, Imperial College London, UK
,
Robin J. Leatherbarrow
2   Biological and Biophysical Chemistry Section, Department of Chemistry, Imperial College London, UK
,
Vincent Ellis
1   School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
› Institutsangaben

Financial support:This study was supported by the Norfolk and Waveney Big C Cancer Charity, the John and Pamela Salter Charitable Trust and by European Union FP6 (Cancerdegradome) project.
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Publikationsverlauf

Received: 04. November 2013

Accepted after major revision: 10. März 2014

Publikationsdatum:
21. November 2017 (online)

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Summary

Matriptase is a type-II transmembrane serine protease involved in epithelial homeostasis in both health and disease, and is implicated in the development and progression of a variety of cancers. Matriptase mediates its biological effects both via as yet undefined substrates and pathways, and also by proteolytic cleavage of a variety of well-defined protein substrates, several of which it shares with the closely-related protease hepsin. Development of targeted therapeutic strategies will require discrimination between these proteases. Here we have investigated cyclic microproteins of the squash Momordica cochinchinensis trypsin-inhibitor family (generated by total chemical synthesis) and found MCoTI-II to be a high-affinity (Ki 9 nM) and highly selective (> 1,000-fold) inhibitor of matriptase. MCoTI-II efficiently inhibited the proteolytic activation of pro-hepatocyte growth factor (HGF) by matriptase but not by hepsin, in both purified and cell-based systems, and inhibited HGF-dependent cell scattering. MCoTI-II also selectively inhibited the invasion of matriptase-expressing prostate cancer cells. Using a model of epithelial cell tight junction assembly, we also found that MCoTI-II could effectively inhibit the re-establishment of tight junctions and epithelial barrier function in MDCK-I cells after disruption, consistent with the role of matriptase in regulating epithelial integrity. Surprisingly, MCoTI-II was unable to inhibit matriptase-dependent proteolytic activation of prostasin, a GPI-anchored serine protease also implicated in epithelial homeostasis. These observations suggest that the unusually high selectivity afforded by MCoTI-II and its biological effectiveness might represent a useful starting point for the development of therapeutic inhibitors, and further highlight the role of matriptase in epithelial maintenance.