SOX6 is downregulated in osteosarcoma and suppresses the migration, invasion and epithelial-mesenchymal transition via TWIST1 regulation.

Transcription factor SOX6 (SOX6) has been reported to serve essential roles in numerous types of cancers. However, the expression and functions of SOX6 in osteosarcoma (OS) have not been analyzed. In the present study, the patterns of SOX6 expression in OS cell lines and tissues were investigated by reverse transcription‑quantitative polymerase chain reaction and western blotting. The results of the present study revealed that SOX6 was notably downregulated in OS tissues and cell lines. Subsequently, gain‑ and loss‑of‑function studies demonstrated that SOX6 inhibited OS cell migration and invasion. In addition, SOX6 may have suppressed epithelial‑mesenchymal transition via twist‑related protein 1 (TWIST1) modulation. Chromatin immunoprecipitation (ChIP), quantitative ChIP and dual luciferase activity assays were used to confirm the binding of SOX6 to the promoter region of TWIST1. Additionally, colony formation assays and Cell Counting Kit‑8 assays demonstrated that SOX6 suppressed cell proliferation. The findings of the present study indicated that SOX6 serves as a tumor suppressor in OS and may be a potential therapeutic target for OS.