title: Understanding central carbon metabolism of rapidly proliferating mammalian cells based on analysis of key enzymatic activities in GS-CHO cell lines.
abstract: The central carbon metabolism (glycolysis, the pentose phosphate pathway [PPP], and the tricarboxylic acid [TCA] cycle) plays an essential role in the supply of biosynthetic precursors and energy. How the central carbon metabolism changes with the varying growth rates in the in vitro cultivation of rapidly proliferating mammalian cells, such as cancer cells and continuous cell lines for recombinant protein production, remains elusive. Based on relationships between the growth rate and the activity of seven key enzymes from six cell clones, this work reports finding an important metabolic characteristic in rapidly proliferating glutamine synthetase-Chinese hamster ovary cells. The key enzymatic activity involved in the TCA cycle that is responsible for the supply of energy became elevated as the growth rate exhibited increases, while the activity of key enzymes in metabolic pathways (glycolysis and the PPP), responsible for the supply of biosynthetic precursors, tended to decrease-suggesting that rapidly proliferating cells still depended predominantly on the TCA cycle rather than on aerobic glycolysis for their energetic demands. Meanwhile, the growth-limiting resource was most likely biosynthetic substrates rather than energy provision. In addition, the multifaceted role of glucose-6-phosphate isomerase (PGI) was confirmed, based on a significant correlation between PGI activity and the percentage of G2/M-phase cells.
authors.affiliation: School of Chemical and Bioprocess Engineering, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, Ireland.
authors.forename: Wu
authors.initials: W
authors.lastname: Zou
authors.affiliation: School of Chemical and Bioprocess Engineering, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, Ireland. m.al-rubeai@ucd.ie.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Rubeai
mesh_terms: D000818:Animals; D016466:CHO Cells; D002244:Carbon / Q000378:metabolism*; D049109:Cell Proliferation; D002470:Cell Survival; D002952:Citric Acid Cycle; D006224:Cricetinae; D003412:Cricetulus; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism*; D006019:Glycolysis; D007700:Kinetics; D064688:Metabolic Flux Analysis; D010427:Pentose Phosphate Pathway
chemical_list: D002244:Carbon; D005956:Glucose-6-Phosphate Isomerase
keywords: CHO cells; central carbon metabolism; enzymatic activity; glucose-6-phosphate isomerase; grow rate; metabolic characteristics