c-Met promotes chemotaxis toward a SDF-1 gradient. (A,C) BM cells from G-CSF–treated mice were transduced with lentiviral vectors expressing a c-Met shRNA or a nonfunctional control shRNA and subsequently subjected to a chemotaxis assay through Matrigel-coated filters. (A) SDF-1–induced migration or (C) spontaneous migration of BM leukocytes or progenitor cells are shown. (B,D) BM cells taken from mice injected with G-CSF; cells were preincubated with c-Met inhibitor and then subjected to a chemotaxis assay through Matrigel-coated filters. (B) SDF-1–induced migration or (D) spontaneous migration of BM leukocytes or progenitor cells are shown. (E) MMP-9 activity in the BM of mice receiving c-Met Abs, DMSO, or 5 injections of G-CSF with or without anti–c-Met Abs on days 4 and 5 of G-CSF treatment or mice that received 5 injections of G-CSF with vehicle or c-Met inhibitor. Gelatin zymography has been performed on BM supernatants. The data are expressed as mean ± SE in 3 independent experiments *P < .05, **P < .001.