Table of Contents Author Guidelines Submit a Manuscript
The Scientific World Journal
Volume 2013, Article ID 920595, 11 pages
Review Article

Fluctuating Roles of Matrix Metalloproteinase-9 in Oral Squamous Cell Carcinoma

1Biomedicum Helsinki, Institute of Dentistry, Research Laboratory, University of Helsinki, P.O. Box 63, Haartmaninkatu 8, 00014 Helsinki, Finland
2Department of Diagnostics and Oral Medicine, Institute of Dentistry and the Oulu Center for Cell-Matrix Research, University of Oulu, P.O. Box 5281, 90014 Oulu, Finland
3Oulu University Hospital, Oulu, Finland
4Department of Oral and Maxillofacial Diseases, Helsinki University Hospital, Helsinki, Finland

Received 5 November 2012; Accepted 10 December 2012

Academic Editors: S. Bhan, A. Chuang, and J. E. J. Lee

Copyright © 2013 Suvi-Tuuli Vilen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


One hallmark of cancer is the degradation of the extracellular matrix (ECM), which is caused by proteinases. In oral cancers, matrix metalloproteinases (MMPs), especially MMP-9, are associated with this degradation. MMPs break down the ECM allowing cancer to spread; they also release various factors from their cryptic sites, including cytokines. These factors modulate cell behavior and enhance cancer progression by regulating angiogenesis, migration, proliferation, and invasion. The development of early metastases is typical for oral cancer, and increased MMP-9 expression is associated with a poor disease prognosis. However, many studies fail to relate MMP-9 expression with metastasis formation. Contrary to earlier models, recent studies show that MMP-9 plays a protective role in oral cancers. Therefore, the role of MMP-9 is complicated and may fluctuate throughout the different types and stages of oral cancers.