RNAi-mediated knockdown of Dnmt3a enhances antibody titer in CHO cells up to 200 percent

Background Increasing cell specific productivity is still an important challenge in today’s production of biopharmaceuticals in mammalian cell cultures. During the last two decades various efforts were made to achieve higher yields, e.g. by optimization of process strategies, media development or cell line and metabolic engineering. Nevertheless, some challenges remain for efficient and applicable high titer production processes at industrial scale: the stability of engineered cell lines and the complexity of stable high-titer production processes as well as the characterization for regulatory authorities and strategies for downstream processing [1-3]. We found decreased transcript levels of the de novo methyltransferase 3a (Dnmt3a) in independent cultivation processes with increased productivity, i.e. in perfusions under glucose limitation and batch cultivation upon butyrate treatment. To prove the hypothesis that reduced transcript levels of Dnmt3a is responsible for an increase in productivity, we investigated the influence of RNAi-mediated knockdown of Dnmt3a in recombinant CHO cells on cell growth, viability and cellular and process productivity.