Abstract:      Background and purpose: Researches demonstrated that the butyric acid sodium salt (sodium butyrate, NaB) has effect on the inhibition of tumor cell proliferation, differentiation and apoptosis-promoting, while the mechanism on salivary adenoid cystic carcinoma(SACC) is still uncertain. This study mainly probed into the impact of different concentration of sodium butyrate on the migration and invasion of SACC cell line ACC-M, and its mechanism of action. Methods: MTT assay explored the optimal concentration of sodium butyrate on the cell ACC-M and the observation of cell growth. Transwell assay was used to detect the effects of sodium butyrate on the ACC-M cells on the aspact of invasion and migration ability. Fluorescence real-time quantitative PCR (RT-PCR) and Western blot were used to test respectively the expression of HMGB1, TLR4 mRNA and protein in ACC-M after functioned by 5 group drugs with different concentrations. Results: Compared with the control group, on the one hand, the concentration 0.625, 1.25, 2.5, 5 and 10 mmol/L of sodium butyrate could effectively inhibit cell proliferation and apparently showing concentration- dependence (P<0.05)；On the other hand, 5 sets concentration of sodium butyrate could also effectively inhibit invasion and migration ability of ACC-M cells in vitro (P<0.05), as well as reducing the expression of HMGB1, TLR4 mRNA and protein in ACC-M cells (P<0.05). Furthermore related analysis showed that the decline of TLR4 protein expression was positively correlated with inhibition of HMGB1 (r=0.810, P<0.05). Conclusion: Sodium butyrate has an effect on inhibiting ACC-M cell proliferation, significantly reducing ACC-M cell invasion and  igration capabilities, and reducing expression of HMGB1, TLR4 mRNA and protein, and both expression amount are positively correlated, Meanwhile the positively correlation suggests that sodium butyrate probably achieve the inhibition ability by lowering the expression of HMGB1, TLR4 mRNA and protein in ACC-M cell.

Key words: Salivary adenoid cystic carcinoma, Sodium butyrate, High mobility group box-1, Toll like receptor-4, Invasion, Migration