MMP-2 mediates tumor survival in a TGFβ dependent manner.

<p><b>A</b>, Tumor survival in the presence of 1 ng/ml recombinant TGFβ was assessed by soft agar colony formation assay. <b>B</b>, The number of PyMT-Luc colonies formed in response to 10 days of treatment with control media (5% serum containing αMEM) or conditioned media derived from wild type or MMP-2 null osteoblasts was analyzed in a 2D (plastic) assay (non-treated group). Under similar conditions the impact of TGFβ inhibition was also determined (matched isotype antibody was added to control wells). Differences are significant as assessed by ANOVA. <b>C</b>, The effects of blocking TGFβ in the CM derived from WT and MMP-2^−/− osteoblasts was determined by soft agar colony formation assay. Data are mean ± SD. Asterisk indicates p<0.05 and n.s indicates non significance. Double asterisk denotes that the addition of recombinant MMP-2 to MMP-2^−/− CM significantly enhances tumor survival compared to MMP-2^−/− CM alone. <b>D</b>, Osteoblast-derived MMP-2 and TGF-β mediate tumor survival without impacting colony size. Using a soft agar colony formation assay, no difference in colony size was detected between the various treatment conditions. Data are mean ± SD.