Insights into the distinct roles of MMP-11 in tumor biology and future therapeutics (Review).

The biological processes of cancer cells such as tumorigenesis, proliferation, angiogenesis, apoptosis and invasion are greatly influenced by the surrounding microenvironment. The ability of solid malignant tumors to alter the microenvironment represents an important characteristic through which tumor cells are able to acquire specific functions necessary for their malignant biological behaviors. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with the capacity of remodeling extracellular matrix (ECM) by degrading almost all ECM proteins, which plays essential roles during the invasion and metastasis process of solid malignant tumors, including allowing tumor cells to modify the ECM components and release cytokines, ultimately facilitating protease-dependent tumor progression. MMP-11, also named stromelysin-3, is a member of the stromelysin subgroup belonging to MMPs superfamily, which has been detected in cancer cells, stromal cells and adjacent microenvironment. Differently, MMP-11 exerts a dual effect on tumors. On the one hand MMP-11 promotes cancer development by inhibiting apoptosis as well as enhancing migration and invasion of cancer cells, on the other hand MMP-11 plays a negative role against cancer development via suppressing metastasis in animal models. Overexpression of MMP-11 was discovered in sera of cancer patients compared with normal control group as well as in multiple tumor tissue specimens, such as gastric cancer, breast cancer, and pancreatic cancer. At present, some evidence supports that MMP-11 may work as a significant tumor biomarker for early detection of cancer, tumor staging, prognostic analysis, monitoring recurrence during follow-up and also a potential target for immunotherapy against cancer. In view of the importance of MMP-11 in modifying tumor microenvironment and potent antitumoral effects on solid tumors, there is an urgent need for a deeper understanding of how MMP-11 modulates tumor progression, and exploring its potential clinical application.