Development of Magoh protein‐overexpressing HEK cells for optimized therapeutic protein production

In the pharmaceutical industry, the need for high levels of protein expression in mammalian cells has prompted the search for new strategies, including technologies to obtain cells with improved mechanisms that enhance its transcriptional activity, folding, or protein secretion. Chinese Hamster Ovary (CHO) cells are by far the most used host cell for therapeutic protein expression. However, these cells produce specific glycans that are not present in human cells and therefore potentially immunogenic. As a result, there is an increased interest in the use of human‐derived cells for therapeutic protein production. For many decades, human embryonic kidney (HEK) cells were exclusively used for research. However, two products for therapeutic indication were recently approved in the United States. It was previously shown that tethered Magoh, an Exon‐junction complex core component, to specific mRNA sequences, have had significant positive effects on mRNA translational efficiency. In this study, a HEK Magoh‐overexpressing cell line and clones, designated here as HEK‐MAGO, were developed for the first time. These cells exhibited improved characteristics in protein expression, reaching —two‐ to threefold increases in rhEPO protein production in comparison with the wild‐type cells. Moreover, this effect was promoter independent highlighting the versatility of this expression platform.