['To investigate the potential regulation of matrix metalloproteinases (MMPs) by hepatocyte growth factor (HGF), and to identify individual MMPs essential for migration of human corneal epithelial cells.', 'Migration of human corneal epithelial cells (HCECs) was measured with a colony dispersion assay in response to concentrations of HGF (0-50 ng/mL). MMP activity in the conditioned media collected from the dispersion assay was assessed by zymography. The broad-spectrum MMP inhibitor ilomastat (1-100 microM) or an MMP-9-neutralizing antibody (1-10 microg/mL) were included in the dispersion assay to determine their effects on HCEC migration. Immunocytochemistry and in situ hybridization were used to localize MMP-1 in HCECs in the colony dispersion assay and in a human ex vivo corneal wound-healing model, respectively. ELISA for MMP-1 was performed on conditioned medium from migrating HCECs. Neutralizing antibodies to MMP-1 and -9 were added to an in vitro scratch-wound model to assess the effect on HCEC healing.', 'HCEC migration (P < 0.05) and MMP-2 and -9 released into the medium increased in response to HGF in a dose-dependent manner up to 20 ng/mL. Broad-spectrum MMP inhibition significantly reduced HCEC migration (P < 0.05). In contrast, neutralization of MMP-9 increased migration (P < 0.05). MMP-1 was found in association with HCECs at the migratory leading edge in both the dispersion and the ex vivo wound-healing experiments, and was found to be stimulated above basal levels by HGF. Neutralization of MMP-1 significantly decreased (P < 0.05), whereas neutralization of MMP-9 significantly increased (P < 0.05), scratch-wound closure.'] Do human corneal epithelial cells require MMP-1 for HGF-mediated migration on collagen I?