The American journal of pathology
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Ewing's sarcoma is a primitive highly malignant tumor of bone and soft tissues usually metastasizing to bone, bone marrow, and lung. Growth factor receptors and their ligands may be involved in its growth and dissemination. We analyzed the expression of c-kit and its ligand stem cell factor (SCF) in a panel of six Ewing's sarcoma cell lines. ⋯ The in vitro pretreatment of cells with SCF strongly reduced the metastatic ability of Ewing's sarcoma cells, both to the lung and to extrapulmonary sites. This could be dependent on the down-modulation of c-kit expression observed in SCF-pretreated cells, leading to a reduced sensitivity to the chemotactic and proliferative actions of SCF. Our results indicate that the response to SCF mediated by c-kit may be involved in growth, migration, and metastatic ability of Ewing's sarcoma cells.