Sperm-associated antigen 9 (SPAG9) is an oncoprotein involved in the progression of various human malignancies; however, its role in osteosarcoma (OS) remains poorly evaluated. The present study used Matrigel™ cell migration and invasion assays, tube formation assay, Cell Counting kit-8, quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay to investigate the role of SPAG9 in OS cell motility, invasion and angiogenesis. The results of the present study demonstrated that SPAG9 expression was upregulated in OS tissues, as compared with adjacent normal tissues, and knockdown of SPAG9 in an OS cell line inhibited cell motility and invasion via inactivation of metalloproteinase (MMP)-2 and MMP-9. Furthermore, the present study demonstrated that silencing of SPAG9 in OS cells inhibited tube formation, the proliferation of human umbilical vascular endothelial cells, and suppressed vascular endothelial growth factor (VEGF) expression and secretion, contributing to a reduction in angiogenesis. The results of the present study indicated that SPAG9 may be an important regulator in OS and may be involved in metastasis. Therefore SPAG9 may be a promising target for the treatment of metastatic OS.
Keywords: metalloproteinase-2; metalloproteinase-9; metastasis; osteosarcoma; sperm-associated antigen 9; vascular endothelial growth factor.