DownRegulated SOX4 Expression Suppresses Cell Proliferation, Migration, and Induces Apoptosis in Osteosarcoma In Vitro and In Vivo.

The SOX4 transcription factor is involved in various cellular processes, such as embryonic development and differentiation. Deregulated expression of Sox4 in several human cancers has been reported to date, but its biological functions in the progression of osteosarcoma remain unclear. In this study, we found that the expression levels of SOX4 protein were significantly higher in high-grade osteosarcoma tissues and metastatic osteosarcoma tissues. Its overexpression was associated with poor prognosis in osteosarcoma. Knockdown of the SOX4 gene in the osteosarcoma cell lines resulted in decreased cell proliferation, migration, invasion, and induced apoptosis. After SOX4 gene silencing, the protein expression levels of Bax, Caspase-3, and P53 in osteosarcoma cells were significantly elevated, while the protein expression levels of Bcl-2, MMP2, and MMP9 were obviously decreased. In vivo analysis in nude mice further confirmed that knockdown of SOX4 suppressed tumor growth. In conclusion, SOX4 appears to be an important tumor oncogene in the regulation of osteosarcoma cell proliferation, apoptosis, and invasion, and it may be a potential target for effective osteosarcoma therapy.