Figure 1

Basic fibroblast growth factor (bFGF)-induced motility and invasion of ESFT cells. (A and B) An ESFT cell line, RD-ES, was wounded using a rotating silicon tip and treated with growth factors that are typically stored in the bone microenvironment at the indicated concentrations for 12 h: bFGF (10 ng ml⁻¹), IGF-1 (20 ng ml⁻¹), PDGF-BB (20 ng ml⁻¹), HGF (20 ng ml⁻¹), EGF (20 ng ml⁻¹), and TGF-β1(1 ng ml⁻¹). In the control experiment, cells were treated with DMEM containing 0.1% serum. (Panel A) Representative photographs ( × 10) at 0 and 12 h after wounding. Cells were stained with Diff-Quik kit. Bars: 100 μm. (Panel B) The percentage of wound closure corresponds to the distance between the wound edges in five randomly chosen regions. The experiments were repeated at least three times and data are shown as mean±s.d. ^*P<0.05, ^***P<0.001. (C) The chemotaxis of RD-ES cells was assessed by a chemotaxis assay when various concentrations of bFGF were added to the lower chamber. In addition, RD-ES cells (2 × 10⁵) were either left untreated or pre-treated with the indicated concentrations of an anti-bFGF-neutralising antibody and then subjected to the chemotaxis assay. Data are depicted as mean±s.d. of at least three independent experiments. ^**P<0.01 vs control IgG, ^***P<0.001 vs bFGF 0 ng ml⁻¹. (D) Effects of bFGF on chemotaxis of various ESFT cell lines, RD-ES, SK-ES-1, and SK-N-MC, were assessed by the chemotaxis assay. Data are depicted as mean±s.d. of at least three independent experiments. ^**P<0.01, ^***P<0.001 vs an absence of bFGF. (E) Effects of bFGF on the chemotaxis of osteosarcoma and synovial sarcoma cell lines were assessed by the chemotaxis assay. Data are depicted as mean±s.d. of at least three independent experiments. ^***P<0.001 vs an absence of bFGF. (F) In vitro invasion assays were performed in which the indicated growth factors were added to the lower chamber: bFGF (10 ng ml⁻¹), IGF-1 (20 ng ml⁻¹), PDGF-BB (20 ng ml⁻¹). RD-ES cells (2 × 10⁵) were plated onto the upper chamber and incubated for 24 h. The number of cells that migrated across the Matrigel-coated transwell chambers was measured. Experiments were performed in triplicate and repeated at least twice. Data are shown as mean±s.d. ^***P<0.001 vs control.