Matrix metalloproteinases: changing roles in tumor progression and metastasis.

Articles on tumor invasion, metastasis, and angiogenesis in normal and disease states have been well represented among the pages of The American Journal of Pathology. In addition to exciting interest in a variety of disease processes, these studies have been central in defining the emerging field in cancer research known as the tumor microenvironment. Early studies in this field established the importance of the extracellular matrix on tumor cell growth and differentiation. With time, the role of the extracellular matrix and matrix metalloproteinases in the regulation of tumor invasion, metastasis, and angiogenesis was recognized, and AJP has published seminal articles in this field. Moreover, recent studies show evidence for a role of matrix metalloproteinases in the regulation of inflammation within tumor lesions, making the targeting of matrix metalloproteinases in cancer therapy even more complex. This review attempts to summarize the contribution of AJP to some of the key changes that have led to the evolution of this field. Published by Elsevier Inc.