Butyrate promotes oral squamous cell carcinoma cells migration, invasion and epithelial-mesenchymal transition

Oral squamous cell carcinoma (OSCC), the most common type of primary malignant tumor in the oral cavity, is a lethal disease with high recurrence and mortality rates. Butyrate, a metabolite produced by periodontal pathogens, has been linked to oral diseases. The purpose of this study was to evaluate the effect of sodium butyrate (NaB) on the proliferation, migration, and invasion of OSCC cells in vitro and to explore the potential mechanism.

Two OSCC cell lines (HSC-4 and SCC-9) were treated with NaB at different concentrations. The cell proliferation was assayed by CCK-8, ethylene deoxyuridine (EdU), and flow cytometry. Wound healing and transwell assay were performed to detect cell migration and invasion. Changes in epithelial-mesenchymal transition (EMT) markers, including E-cadherin, Vimentin, and SNAI1, were evaluated by quantitative real-time PCR (qRT-PCR), western blot, and immunofluorescent staining. The expression levels of matrix metalloproteinases (MMPs) were analyzed by qRT-PCR and gelatin zymography.

Our results showed that NaB inhibited the proliferation of OSCC cells and induced cell cycle arrest at G1 phase, but NaB significantly enhanced cell migration and invasion compared with the control group. Further mechanistic investigation demonstrated that NaB induced EMT by increasing the expression of Vimentin and SNAI1, decreasing the expression of membrane-bound E-cadherin, and correspondingly promoting E-cadherin translocation from the membrane to the cytoplasm. In addition, the overexpression of MMP1/2/9/13 was closely related to NaB treatment.

Our study conclude that butyrate may promote the migration and invasion of OSCC cells by inducing EMT. These findings indicate that butyrate may contribute to OSCC metastasis.