HSA/TIMP-2 does not inhibit MMP-2 activity.

<p>(A) <i>In vitro</i> MMP-2 inhibitory activity was measured by co-incubating with a MMP-2 NIRF probe and activated MMP-2 in the presence of TIMP-2, MMP-2 inhibitors, or HSA/TIMP-2, followed by fluorescence imaging with an IVIS-200 imaging system (<i>top</i>). The corresponding fluorescence intensity (p/s) was quantified in each sample from 3 independent experiments (<i>bottom</i>). A reaction containing NIRF and MMP-2 was used as a positive control in this experiment (lane 4). (B) Representative whole-body NIRF images. NIRF imaging of MLL tumor-bearing mice was performed at 2 h after injection of the MMP-2 NIRF probe in the presence of MMP I (<i>n</i> = 4), HSA/TIMP-2 (<i>n</i> = 5), or control PBS (<i>n</i> = 6). (C) The quantitation of fluorescent signal in the tumor. The fluorescence intensity (p/s) was quantified based on the total photon count determined from regions of interest. Each data point represents the mean ± SEM; ^#<i>P</i><0.05 <i>vs.</i> control group by two-way ANOVA followed by Bonferroni post-hoc test.