title: The matrix metalloproteinase stromelysin-1 acts as a natural mammary tumor promoter.
abstract: Extracellular matrix-degrading matrix metalloproteinases (MMPs) are invariably upregulated in epithelial cancers and are key agonists in angiogenesis, invasion and metastasis. Yet most MMPs are secreted not by the cancer cells themselves, but by stromal cells within and around the tumor mass. Because the stromal environment can influence tumor formation, and because MMPs can alter this environment, MMPs may also contribute to the initial stages of cancer development. Several recent studies in MMP-overexpressing and MMP-deficient mice support this possibility, but have required carcinogens or pre-existing oncogenic mutations to initiate tumorigenesis. Here we review the spontaneous development of premalignant and malignant lesions in the mammary glands of transgenic mice that express an autoactivating form of MMP-3/stromelysin-1 under the control of the whey acidic protein gene promoter. These changes were absent in nontransgenic littermates and were quenched by co-expression of a human tissue inhibitor of metalloproteinases-1 (TIMP-1) transgene. Thus by altering the cellular microenvironment, stromelysin-1 can act as a natural tumor promoter and enhance cancer susceptibility.
authors.affiliation: Department of Anatomy, University of California, 513 Parnassus Avenue, HSW-1301, San Francisco, California, CA 94143-0452, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Sternlicht
authors.forename: M J
authors.initials: MJ
authors.lastname: Bissell
authors.forename: Z
authors.initials: Z
authors.lastname: Werb
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000201:enzymology* / Q000235:genetics; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism*; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020782:Matrix Metalloproteinases; D019278:Matrix Metalloproteinase 3