Ophiopogon Saponin B Affects the Proliferation, Apoptosis, and Oxidative Stress of Osteosarcoma Cells by Regulating POU Class 3 Homeobox 3 Expression

Osteosarcoma is characterized by early lung metastasis and a high recurrence rate. Research on anti-osteosarcoma drugs is progressing slowly, and patient survival rates have not been improved. Ophiopogon saponin B (OP-B), a steroidal saponin monomer extracted from the ophiopogon japonicus, is effective in the treatment of many cancers. We explored the mechanism underlying the in vitro effects of OP-B on proliferation, apoptosis, and oxidative stress in cultured osteosarcoma U2OS cells. We observed significant reductions in optical density, clonal number, and expression of superoxide dismutase, glutathione peroxidase, and POU Class 3 Homeobox 3 (POU3F3) in the presence of OP-B. OP-B also increased the apoptotic rate and malondialdehyde expression. Downregulation of POU3F3 inhibited U2OS proliferation and oxidative stress in osteosarcoma cells and promoted apoptosis. OP-B reduced POU3F3 expression in U2OS cells, and overexpression of POU3F3 reversed the effects of OP-B on proliferation, apoptosis, and oxidative stress. We thus conclude that OP-B promotes apoptosis and inhibits proliferation and the oxidative stress response of osteosarcoma cells by downregulating POU3F3 expression. These results suggest an avenue for the research and development of new drugs for osteosarcoma.