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Yanggu, South Korea

Hong J.K.,KAIST | Hong J.K.,Bio R and nter | Lee G.M.,KAIST | Yoon S.K.,Bio R and nter
Journal of Biotechnology | Year: 2011

The effect of growth factor (GF) and sodium butyrate (NaBu) on Chinese hamster ovary (CHO) cell growth, cell viability and antibody production was investigated using shaking flasks in GF-containing and GF-deficient medium containing 0, 1 and 3mM NaBu. The withdrawal of GF and the addition of NaBu suppressed cell growth, but they significantly increased specific antibody productivity, q Ab. Interestingly, the withdrawal of GF in combination with the addition of NaBu markedly retarded cell death, leading to extended culture longevity. For instance, at 3mM NaBu, cell viability fell below 80% after day 4 in GF-containing medium, but it remained over 80% until day 18 in GF-deficient medium. Due to the enhanced q Ab and the extended culture longevity, approximately 2-fold increase in total antibody production was achieved in pseudo-perfusion culture with 1mM NaBu in GF-deficient medium, compared to the culture in GF-containing medium. The effect of GF and NaBu on the change in the expression and activity of cellular proteins, c-Myc, Bcl-2 and pyruvate dehydrogenase (PDH), was also investigated. Both the withdrawal of GF and the addition of NaBu decreased the expression of c-Myc. The expression of Bcl-2 was enhanced by the addition of NaBu in a dose-dependent manner while it was not affected by the withdrawal of GF. In addition, both the withdrawal of GF and the addition of NaBu reduced metabolic rates, q Glc, q Lac and Y Lac/Glc, and increased PDH activity while not affecting PDH expression, suggesting that they may reduce the glycolytic rates, but enhance the conversion rates of pyruvate to TCA intermediates. Taken together, the withdrawal of GF in combination with the addition of NaBu can be considered as a relevant strategy for alleviating NaBu-induced cell apoptosis and enhancing antibody production since it can be easily implemented as well as enhance q Ab and extend culture longevity. © 2011 Elsevier B.V. Source

Hwang S.-J.,KAIST | Hwang S.-J.,Bio R and nter | Jeon C.-J.,Bio R and nter | Cho S.M.,Bio R and nter | And 2 more authors.
Biotechnology Progress | Year: 2011

To investigate the effect of chemical chaperones on the production and aggregation of flag-tagged cartilage oligomeric matrix protein-Angiopoietin1 (FCA1) in recombinant Chinese hamster ovary (CHO) cells, CHO cells were cultivated in serum-free media with various chemical chaperones, 1 mM 4-phenylbutyrate (4-PBA), 200 mM proline, 3% glycerol, 2% dimethyl sulfoxide (DMSO), and without chemical chaperone as control. The addition of chemical chaperones enhanced FCA1 production and specific FCA1 productivity, qFCA1. For example, the qFCA1 at 200 mM proline was fourfold higher than that at control. Unlike qFCA1, the aggregation of FCA1 was strongly affected by which chemical chaperone was added. The addition of 2% DMSO and 200 mM proline significantly reduced the proportion of aggregates, but the addition of 1 mM 4-PBA and 3% glycerol was hardly effective. The proportions of aggregates were 29.5 and 55.6% at 2% DMSO and 200 mM proline, respectively, whereas it was 79.6% at control. The exact mechanism how chemical chaperones affected the aggregation of FCA1 was not investigated in this study, and therefore, more extensive works will be needed to clarify why different chemical chaperones behaved differently in reducing the aggregation of FCA1. Among chemical chaperones tested, DMSO was the most effective one in regard to enhancing the production and reducing the aggregation of FCA1 in CHO cells. © 2011 American Institute of Chemical Engineers. Source

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