[Sodium butyrate down-regulates IFN-γ-induced indoleamine 2, 3 dioxygenase and promotes its acetylation and ubiquitination in CNE2 nasopharyngeal carcinoma cells].

OBJECTIVE

To investigate molecular mechanisms of posttranslational regulation of sodium butyrate (NaB) on indoleamine 2, 3-dioxygenase (IDO) expression induced by interferon γ (IFN-γ) in CNE2 nasopharyngeal carcinoma cells.

METHODS

Western blotting and co-immunoprecipitation assay were used to detect the expression, acetylation and ubiquitination of IDO in CNE2 nasopharyngeal carcinoma cells.

RESULTS

Western blotting demonstrated that while the cells were treated with IFN-γ and NaB compared with IFN-γ treatment only, the expression of IDO protein increased significantly; furthermore, in the co-immunoprecipitation assay, while the cells were treated with IFN-γ and NaB compared with the ones treated with IFN-γ only, acetylation and ubiquitination of IDO increased significantly. Western blotting showed that the cells treated with NaB and IFN-γ presented with lower IDO protein expression than the ones treated with NaB, IFN-γ and bortezomib simultaneously.

CONCLUSION

NaB could down-regulate the expression of IDO induced by IFN-γ in a dose-dependent manner, and the combined treatment of IFN-γ and NaB could promote the acetylation and ubiquitination of IDO in CNE2 nasopharyngeal carcinoma cells.