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Updated: Apr 17, 2026
Generating a Murine Orthotopic Metastatic Breast Cancer Model and Performing Murine Radical Mastectomy
Published on: November 29, 2018
Blockade of MMP14 activity in murine breast carcinomas: implications for macrophages, vessels, and radiotherapy
Eleanor I Ager1, Sergey V Kozin1, Nathaniel D Kirkpatrick1
1Edwin L. Steele Laboratory, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston MA (EIA, SVK, NDK, GS, DPK, VA, YH, SG, MS, YB, DF, RKJ); Department of Surgery (Austin Health), University of Melbourne, Studley Road Heidelberg, VIC, Australia (EIA); Novogen, Hornsby, NSW, Australia (EIA); Novartis Institutes for BioMedical Research, Cambridge, MA (NDK); Centenary Institute of Cancer Medicine and Cell Biology, University of Sydney, Camperdown, NSW, Australia (SG); Department of Biostatistics, Massachusetts General Hospital Biostatistics Center, Boston, Massachusetts (AM, DMF); Department of Pathology, NYU Langone Medical Center and Medical School, New York, NY (MS); Dyax Corp., Burlington, MA (DTD, LD); Departments of Medical Oncology and Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (SG); Tokai Pharmaceuticals, Inc., Cambridge, MA (DTD); Merck Serono S. A., Geneva, Switzerland (LD).
Background:
Matrix metalloproteinase (MMP) 14 may mediate tumor progression through vascular and immune-modulatory effects.
Methods:
Orthotopic murine breast tumors (4T1 and E0771 with high and low MMP14 expression, respectively; n = 5-10 per group) were treated with an anti-MMP14 inhibitory antibody (DX-2400), IgG control, fractionated radiation therapy, or their combination. We assessed primary tumor growth, transforming growth factor β (TGFβ) and inducible nitric oxide synthase (iNOS) expression, macrophage phenotype, and vascular parameters. A linear mixed model with repeated observations, with Mann-Whitney or analysis of variance with Bonferroni post hoc adjustment, was used to determine statistical significance. All statistical tests were two-sided.
Results:
DX-2400 inhibited tumor growth compared with IgG control treatment, increased macrophage numbers, and shifted the macrophage phenotype towards antitumor M1-like. These effects were associated with a reduction in active TGFβ and SMAD2/3 signaling. DX-2400 also transiently increased iNOS expression and tumor perfusion, reduced tissue hypoxia (median % area: control, 20.2%, interquartile range (IQR) = 6.4%-38.9%; DX-2400: 1.2%, IQR = 0.2%-3.2%, P = .044), and synergistically enhanced radiation therapy (days to grow to 800mm(3): control, 12 days, IQR = 9-13 days; DX-2400 plus radiation, 29 days, IQR = 26-30 days, P < .001) in the 4T1 model. The selective iNOS inhibitor, 1400W, abolished the effects of DX-2400 on vessel perfusion and radiotherapy. On the other hand, DX-2400 was not capable of inducing iNOS expression or synergizing with radiation in E0771 tumors.
Conclusion:
MMP14 blockade decreased immunosuppressive TGFβ, polarized macrophages to an antitumor phenotype, increased iNOS, and improved tumor perfusion, resulting in reduced primary tumor growth and enhanced response to radiation therapy, especially in high MMP14-expressing tumors.
Insights
Matrix metalloproteinase 14 (MMP14) blockade reduced tumor growth and enhanced radiation therapy efficacy. This MMP14 inhibition shifted macrophages to an antitumor state, decreased immunosuppressive factors, and improved tumor perfusion, particularly in high MMP14-expressing tumors.
Area of Science:
- Oncology
- Immunology
- Radiotherapy
Background:
- Matrix metalloproteinase 14 (MMP14) plays a role in tumor progression via vascular and immune modulation.
- Understanding MMP14's role is crucial for developing novel cancer therapies.
Purpose of the Study:
- To investigate the therapeutic potential of targeting MMP14 in breast cancer models.
- To evaluate the effects of MMP14 inhibition on tumor growth, immune microenvironment, and response to radiation therapy.
Main Methods:
- Orthotopic murine breast tumor models (4T1 and E0771) with varying MMP14 expression were treated with an anti-MMP14 antibody (DX-2400), control IgG, radiation, or combination therapy.
- Tumor growth, TGFβ and iNOS expression, macrophage phenotype, and vascular parameters were assessed.
- Statistical significance was determined using appropriate models and post hoc tests.
Main Results:
- DX-2400 treatment inhibited tumor growth, increased antitumor M1-like macrophages, and reduced immunosuppressive TGFβ signaling.
- MMP14 blockade enhanced tumor perfusion, reduced hypoxia, and synergistically improved radiation therapy response in high MMP14-expressing 4T1 tumors.
- These effects were dependent on inducible nitric oxide synthase (iNOS) activity, as demonstrated by inhibition studies.
Conclusions:
- MMP14 blockade effectively reduces primary tumor growth and enhances radiotherapy outcomes, especially in tumors with high MMP14 expression.
- Targeting MMP14 modulates the tumor microenvironment by decreasing immunosuppression and improving vascularization.
- The findings highlight MMP14 as a promising therapeutic target in combination with radiation for breast cancer treatment.
