title: Gene transfer of matrix metalloproteinase-9 induces tumor regression of breast cancer in vivo.
abstract: Matrix metalloproteinases (MMP) are important regulators of angiogenesis and tumor progression by degradation of extracellular matrix. Clinical trials using MMP inhibitors have failed and recent studies suggest that MMPs may in contrast suppress tumor growth. It is not known, however, if MMPs or their inhibitors, tissue inhibitor of metalloproteinases (TIMP), can be used as therapy of established cancer. Here, adenovirus vectors carrying the human genes for MMP-9, TIMP-1, or empty controls were injected intratumorally in breast cancers established in mice supplemented with estradiol and treated with tamoxifen. Microdialysis was used to quantify MMP activity and sampling of endostatin and vascular endothelial growth factor (VEGF) in situ. We show that AdMMP-9 increased MMP activity in vivo, decreased tumor growth rate, and decreased microvessel area significantly. AdMMP-9 therapy resulted in significantly increased levels of endostatin in vivo, whereas VEGF levels were unaffected. As previously shown, tamoxifen exposure by itself increased MMP activity in all treatment groups. Moreover, the combined therapy with AdMMP-9 and tamoxifen further reduced tumor growth and increased the endostatin levels compared with either treatment alone. Gene transfer of TIMP-1 had no effects on tumor progression and counteracted the therapeutic effect of tamoxifen in our breast cancer model. This is the first report showing that overexpression of MMP-9 results in increased generation of antiangiogenic fragments, decreased angiogenesis, and therapeutic effects of established breast cancer.
authors.affiliation: Linköping University, Department of Clinical and Experimental Medicine, Division of Oncology, University Hospital, Linköping, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Bendrik
authors.forename: Jennifer
authors.initials: J
authors.lastname: Robertson
authors.forename: Jack
authors.initials: J
authors.lastname: Gauldie
authors.forename: Charlotta
authors.initials: C
authors.lastname: Dabrosin
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018450:Disease Progression; D043169:Endostatins / Q000378:metabolism; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000628:therapy; D012074:Remission Induction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics; D047368:Tumor Burden; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D043169:Endostatins; D019715:Tissue Inhibitor of Metalloproteinase-1; D042461:Vascular Endothelial Growth Factor A; D020780:Matrix Metalloproteinase 9