Host-derived MMP-2 impacts tumor survival in the bone microenvironment.

<p><b>A</b>, Representative photomicrograph of MCM2 positive proliferating (brown) cells in the wild type (WT) and MMP-2 null (MMP-2^−/−) tumor-bone microenvironment. <b>B</b>, Proliferation in the tumor-bone microenvironment as a function of total cell number was assessed by staining for Mcm2 in tumor bearing tibias of WT and MMP-2 null mice at day 3 and day 6 post-surgery. <b>C</b>, Representative photomicrograph of caspase-3 positive apoptotic (brown) cells in the wild type (WT) and MMP-2 null (MMP-2^−/−) tumor-bone microenvironment. <b>D</b>, Apoptosis in the tumor-bone microenvironment as a function of total cell number was assessed by staining for cleaved caspase-3 at day 3 and day 6 post surgery. Data are mean ± SD; n.s. implies a non-significant p value (p>0.05).