Abstract: Abstract： Objective To investigate the effects of interferon-gamma (IFN-γ) on migration， invasion and vasculogenic mimicry (VM) formation of human melanoma cell line MUM-2B. Methods MUM-2B cells were divided into three groups, control group (10%FBS in DMEM), treatment group1 (10 μg/L IFN-γ) and treatment group2 (100 μg/L IFN-γ). Different concentrations of IFN-γ were added in the culture medium of MUM-2B cells. Wound- healing assay and matrigel invasion assay were performed to examine the migration and invasion ability of MUM-2B cells. Three-D culture was used to observe the VM formation. The expression of vascular endothelial growth factor (VEGF) of MUM-2B cells was detected by Western blot assay. Results The result of wound-healing assay showed that the migration distance of cells was decreased in treat⁃ ment groups compared with that of control group. The migration distance of cells was decreased in treatment group2 com⁃ pared with that of treatment group 1(P < 0.05). The result of matrigel invasion assay showed that the number of invaded cells was decreased in treatment groups compared with that of control group, and which was significantly decreased in treatment group2 than that of treatment group1 (P < 0.05). The result of 3-D culture showed that cells in control group can form typical VM tube-like structures, whereas cells in treatment groups cannot. Western blot assay showed that the expression of VEGF protein was significantly decreased in treatment groups compared with that of control group, and the expression of VEGF pro⁃ tein was significantly decreased in treatment group2 than that of treatment group 1(P < 0.05). Conclusion These data sug⁃ gest that IFN-γ inhibits migration and invasion of MUM-2B cells, and inhibits VM formation by down regulating VEGF ex⁃ pression in vitro.

Key words: melanoma, interferon-gamma, recombinant, vascular endothelial growth factors, cancer stem cells, vasculogenic mimicry