Effect of invadosome-inhibiting peptides on leukemia-cell extravasation and circulating MMP-9 levels. (A-D) 125I-labeled OCI-AML-3 cells were administered intravenously into Balb/c mice with peptide (200 μg), anti-HFDDDE (20 μg), or preimmune IgG. At 1 hour after inoculation, mice were killed, and tissues were harvested, weighed in, and subjected to a γ-counter. (E) 125I-labeled Jurkat leukemia T cells were administered as described previously. (F) Peptide alone was administered intravenously, and serum MMP-9 activity was measured by gelatin zymography. (A-F) Shown are means ± SD from triplicates. *P < .005 (t test) of HFDDDE or antibody-treated mice compared with control mice.