Expression of Human Erythropoietin Containing 2 Additional N-Link in CHO-K1 Cells under Different Culture Conditions

Abstract

Human erythropoietin (hEPO) is a glycoprotein that regulates the formation of erythrocytes and mainly used in anemia patients. Previously, we have reported the expression of modified human EPO with 2 additional N-linked in mammalian cell CHO-K1. The aim of this current research was to study the optimum condition for modified recombinant hEPO (rhEPO) production in CHO-K1. To do this, several parameters of culture conditions were applied including antibiotic concentrations, seeding densities, time of incubations, fetal bovine serum (FBS) concentrations and cell culture media. The result showed that the presence of antibiotic G418 improved the expression level with the highest was at 1% of concentration. Meanwhile, seeding density of 2–3x105 cells/6 cm dish and seven day of incubation time were the best condition for rhEPO protein expression. From five different combination media used, F12 medium with 10% FBS gave the highest expression of rhEPO protein. From this study was also found that at passage 16 the expression level was still increasing proving that the clone expressing the protein of our interest is promisingly stable. Keywords : EPO, erythropoietin, protein expression, CHO-K1, optimation