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This study explored the cell line-specific effects of dexamethasone (DEX) on three antibody-producing Chinese hamster ovary (CHO) clones derived from different parental host cell lines: CHO-K1, -S, and -DG44. The CHO-K1 and -DG44 cell lines displayed DEX-concentration-dependent growth inhibition but had improved viability in later culture stages, extending culture longevity. Conversely, the CHO-S cell line was less sensitive to DEX regarding cell growth but exhibited a drastic decrease in viability in the later stages of culture. The cell line-specific impact of DEX (i.e. the anti-apoptotic or pro-apoptotic effects) could have resulted from the presence or absence of the GRα-D isoform and relative level of GRα-C isoform in these cell lines. The CHO-K1 and -DG44 cell lines, which expressed GRα-D and relatively low levels of GRα-C, displayed improved cell viability in response to DEX. In contrast, the CHO-S cell line, which lacked GRα-D expression with relatively higher levels of GRα-C, exhibited pro-apoptotic effects upon exposure to DEX. DEX also influenced glucose consumption and metabolite production in all three cell lines, while its effects on antibody quality were negligible. Therefore, when supplementing glucocorticoids such as DEX in cell culture media, it is crucial to assess their ability to enhance culture performance carefully. This study could provide insights for optimizing production media to specific cell lines within the bioprocessing field. [ABSTRACT FROM AUTHOR]

Cell line instability is a common problem in biopharmaceutical manufacturing using Chinese hamster ovary (CHO) cells. Cell line instability, which refers to unintended and unpredicted genetic, epigenetic, and phenotypic changes over time, can increase production costs and threaten sales approval by reducing product quantity and quality. While a stability test is conducted to screen cell lines with stable transgene expression, this process requires several months, delaying the entire drug development timeline. To accelerate timeline for drug development, understanding, mitigation, and prediction of cell line instability are critical. In this review, we update recent research progresses regarding instability-inducing biological mechanisms and alleviating the intrinsic instability of CHO cells. We also discuss studies that contribute to predicting irregular phenotypic changes in recombinant protein-producing CHO cell lines, based on omics-based studies. These prediction strategies will contribute to complementing current instability alleviating strategies, thereby saving labor, cost, and time for the cell line development process as well as providing a comprehensive understanding of CHO cell biology. [ABSTRACT FROM AUTHOR]

Polyamines such as putrescine (PUT), spermidine (SPD), and spermine (SPM) are amine group-containing biomolecules that regulate multiple intracellular functions such as proliferation, differentiation, and stress response in mammalian cells. Although these biomolecules can be generated intracellularly, lack of polyamine-synthesizing activity has occasionally been reported in a few mammalian cell lines such as Chinese hamster ovary (CHO)-K1; thus, polyamine supplementation in serum-free media is required to support cell growth and production. In the present study, the effects of biogenic polyamines PUT, SPD, and SPM in media on cell growth, production, metabolism, and antibody quality were explored in cultures of antibody-producing CHO-K1 cells. Polyamine withdrawal from media significantly suppressed cell growth and production. On the other hand, enhanced culture performance was achieved in polyamine-containing media conditions in a dose-dependent manner regardless of polyamine type. In addition, in polyamine-deprived medium, distinguishing metabolic features, such as enriched glycolysis and suppressed amino acid consumption, were observed and accompanied by higher heterogeneity of antibody quality compared with the optimal concentration of polyamines. Furthermore, an excessive concentration of polyamines negatively affected culture performance as well as antibody quality. Hence, the results suggest that polyamine-related metabolism needs to be further investigated and polyamines in cell growth media should be optimized as a controllable parameter in CHO cell culture bioprocessing. Key points: • Polyamine supplementation enhanced cell growth and production in a dose-dependent manner • Polyamine type and concentration in the media affected mAb quality • Optimizing polyamines in the media is suggested in CHO cell bioprocessing [ABSTRACT FROM AUTHOR]

Chinese hamster ovary (CHO) cell lines have been widely used to produce recombinant proteins. While the biosynthesis of recombinant proteins is energy-intensive, CHO cells exhibit inefficient metabolism, characterized by rapid conversion of glucose to lactate, possibly leading to lower cell growth and productivity of therapeutic proteins. Therefore, it is important to understand and engineer cellular metabolism to increase recombinant protein production. In this review, cellular energy metabolism of CHO cells with respect to protein synthesis is overviewed. Then, genetic and process engineering approaches to enhance metabolic efficiency are described, resulting in the improvement of cell culture performance. Finally, recent modeling technologies for understanding and predicting cellular metabolic behaviors are reviewed. These efforts will aid to further advance the biomanufacturing of therapeutic proteins. [ABSTRACT FROM AUTHOR]