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. 2015 May 27;17(5):421–433. doi: 10.1016/j.neo.2015.04.003

Figure 3.

Figure 3

MMP9 promotes tumor onset in the C3(1)-Tag but not in the MMTV-Neu mouse model of breast cancer. (A) MMP9 is expressed in neutrophils/monocytes and (B) macrophages in tumors of both MMTV-Neu and C3(1)-Tag mice. Tumors were stained for reactivity against Ly6B.2 (clone 7/4, for neutrophils/monocytes), F4/80 (for macrophages), and MMP9. Lower panels are high magnifications of indicated areas. All sections were counterstained with 4′,6-diamidino-2-phenylindole for visualization of cell nuclei. Scale bars, 50 μm. (C and D) The percentages of neutrophils/monocytes and macrophages expressing MMP9 were the same in the MMTV-Neu and C3(1)-Tag models (n.s., not significant, Mann-Whitney, two-sided). (E and F) Neutrophils/monocytes constituted a higher percentage of MMP9-expressing cells in the C3(1)-Tag models than in the MMTV-Neu model (P = .09, Mann-Whitney), while macrophages constituted a higher percentage of MMP9-expressing cells in the MMTV-Neu model than in the C3(1)-Tag model (P = .02, Mann-Whitney, two-sided). (G) Kaplan-Meier curves showing tumor-free survival of MMTV-Neu;Mmp9+/+, MMTV-Neu;Mmp9+/−, and MMTV-Neu;Mmp9−/− mice. No significant differences among the curves were observed. (H) Kaplan-Meier curves showing tumor-free survival of C3(1)-Tag;Mmp9+/+, C3(1)-Tag;Mmp9+/−, and C3(1)-Tag;Mmp9−/− mice. A significant delay (P = .002, log rank test) in tumor onset was observed in C3(1)-Tag;Mmp9−/− compared to C3(1)-Tag;Mmp9+/+ mice.