Sodium butyrate inhibits oral squamous cell carcinoma proliferation and invasion by regulating the HDAC1/HSPB7 axis.

The study was performed to ascertain the mechanism of sodium butyrate (NaB) mediating the proliferative and invasive properties of oral squamous cell carcinoma (OSCC) cells. The cell proliferative, migrating, and invasive potentials were detected by CCK-8, colony formation, EdU, and Transwell assays. The expression of proliferation- and invasion-related proteins, HDAC1, and HSPB7 in OSCC cells were evaluated by western blot. Immunofluorescence was also performed to evaluate the HDAC1 expression. The enrichment of histone deacetylase HDAC1 in the promoter region of HSPB7 was assessed by the ChIP assay. In vivo growth of OSCC cells was measured by tumorigenesis in nude mice (n=18). The t-test was employed for comparisons of data between the two groups. One-way ANOVA was utilized for comparisons of data among multiple groups, and repeated-measures ANOVA for comparisons of data at different time points among groups, followed by Bonferroni post-hoc test. The data showed that HDAC1 expression was highly upregulated in OSCC cells compared to human normal oral keratinocytes (HNOKs) (p<0.0001), and NaB diminished the HDAC1 expression in OSCC cells. NaB restricted OSCC cell proliferative, migrating, and invasive capabilities by downregulating HDAC1. HSPB7 expression was downregulated in OSCC cells versus HNOKs (p<0.0001). HDAC1 inversely orchestrated the HSPB7 expression in OSCC cells through histone deacetylation modification, and NaB augmented the HSPB7 expression by inhibiting HDAC1. Moreover, NaB inhibited OSCC cell growth in vivo by elevating HSPB7 levels through the HDAC1 repression. In conclusion, NaB restrained cell proliferation and invasion in OSCC cells via HSPB7 upregulation by decreasing the HDAC1 expression.