SOX5 promotes cell invasion and metastasis via activation of Twist-mediated epithelial–mesenchymal transition in gastric cancer

BACKGROUND: Sex-determining region Y-box protein 5 (SOX5) has been demonstrated to be implicated in oncogenic function in various types of cancers. However, the role of SOX5 in gastric cancer (GC) remains poorly elucidated. Herein, we investigated the role and the underlying mechanism of SOX5 in GC progression. METHODS: SOX5 mRNA and protein expression were detected by quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry in human GC specimens, and their clinical significance was evaluated. The effects of SOX5 knockdown or overexpression on GC cell behavior were determined by proliferation, wound-healing and transwell assays in vitro, and metastasis assays in vivo; and epithelial–mesenchymal transition (EMT)-related markers were detected by qRT-PCR, Western blot and immunofluorescence staining. RESULTS: The up-regulated expression of SOX5 in GC specimens was significantly correlated with clinical metastasis and poor prognosis for patients with GC. Besides, SOX5 promoted GC cell migration and invasion in vitro, as well as GC cell metastasis in vivo. Mechanically, Twist-mediated EMT was likely involved in SOX5-facilitated GC cell behavior. CONCLUSION: SOX5 has an important function in GC progression. In addition, SOX5 promotes GC cell invasion and metastasis via activation of Twist-mediated EMT, thus providing a potential therapeutic target for GC metastasis.