Matrix metalloproteinases in remodeling of the normal and neoplastic mammary gland.

Alterations in mammary gland structure and function are associated with changes in the expression of members of the matrix metalloproteinase (MMP)3 family of enzymes. In this review, the evidence for a role for specific MMPs in mammary gland development and cellular differentiation, proliferation, and apoptosis is discussed. In addition, MMP expression is altered during the development and progression of preneoplastic and neoplastic breast lesions. The expression of MMP family members in human breast cancer is described, and studies with mouse model systems addressing the role of MMPS in the initiation, growth, invasion, and metastasis of breast neoplasms are reviewed.