Effect of Histone Deacetylase Inhibitors on the Production of Albumin-EPO in CHO Cells

초록

Chinese hamster ovary (CHO) cells are the most widely used mammalian host for the commercial production of biotherapeutics. Recent developments with CHO cells have focused on increasing specific productivity in cell culture. There are numerous small molecule enhancers that can increase protein production. Effects of histone deacetylase inhibitor (HDACi) on the enhanced production of recombinant proteins expressed in CHO cells has been reported.1) Sodium butyrate, sodium propionate and valproic acid are known to be effective inhibitors of histone deacetylation.2) These compounds induce histone hyperacetylation and enhance the expressed mRNA transcription level of target protein. In addition, HDACi can also enhance the protein production by arresting the cell cycle at G1 productive phase.3) Although the addition of HDACi increases the production of target protein, it inhibits the proliferation of cells and induces apoptotic cell death. To determine the effects of HDACi on the production of recombinant albumin-erythropoietin (alb-EPO) fusion protein, various inhibitors were added to the cultures of exponentially growing cells. Among the inhibitors tested, sodium propionate and sodium butyrate were found to be efficient. We optimized the concentration of the two compounds to improve the production of alb-EPO with minimal growth inhibition. It was observed that 1 mM was optimal for both compounds considering cell growth as well as alb-EPO production. These compounds arrested the cell cycle in G1 phase. Compared with the cultures without sodium butyrate, the culture with 1 mM sodium butyrate resulted in a 1.4-fold increase in alb-EPO concentration on day 6. These results demonstrate the potential of HDACi to the enhanced commercial production of EPO in CHO cells.