Expression of matrix metalloproteinases and their association with clinical characteristics of solid tumors

Matrix metalloproteinases (MMPs) are a group of zinc-dependent enzyme families that play an important role in regulating human physiological as well as pathological processes, especially in malignant tumors. Numerous experimental studies have shown that MMPs are not only involved in the occurrence and development of solid tumors but also play a key role in the staging and grading of tumors. The specific processes by which MMPs are involved in tumor cell invasion and metastasis mainly include degradation of the extracellular matrix, regulation of gene polymorphism, promotion of epithelial-mesenchymal transformation, and induction of adhesion molecule expression. The correlated expression of MMPs in different solid tumors provides a basis for tumor markers, tumor prognosis, and drug targets. In this review, the function, classification, and nomenclature of MMPs will be summarized, and the relevant expression of MMPs in solid tumors, as well as the clinical survival rate and general prognosis associated with MMPs, will be elaborated to provide useful information on which to base the search for new targets for tumor therapy.