Efficient Selection of Stable Chinese Hamster Ovary (CHO) Cell Lines for Expression of Recombinant Proteins by Using Human Interferon β SAR Element

2008 ◽  
Vol 21 (3) ◽  
pp. 933-937 ◽  
Author(s):  
Jeong Do Kim ◽  
Yeup Yoon ◽  
Hye-Yeon Hwang ◽  
Jeong Soo Park ◽  
Sungryul Yu ◽  
...  
2008 ◽  
Vol 21 (4) ◽  
pp. 1154-1164 ◽  
Author(s):  
Han Kyu Oh ◽  
Moon Kyoung So ◽  
Jihye Yang ◽  
Ho Chul Yoon ◽  
Ji Soo Ahn ◽  
...  

2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Paula Meleady ◽  
Padraig Doolan ◽  
Michael Henry ◽  
Niall Barron ◽  
Joanne Keenan ◽  
...  

1996 ◽  
Vol 313 (3) ◽  
pp. 991-996 ◽  
Author(s):  
Michael R. NARKEWICZ ◽  
S. David SAULS ◽  
Susan S. TJOA ◽  
Cecilia TENG ◽  
Paul V. FENNESSEY

Serine hydroxymethyltransferase (SHMT) is the primary enzyme in the interconversion of serine and glycine. The roles of mitochondrial and cytosolic SHMT in the interconversion of serine and glycine were determined in two Chinese hamster ovary (CHO) cell lines that both contain cytosolic SHMT but either have (CHOm+) or lack (CHOm-) mitochondrial SHMT. Mitochondrial SHMT activity was significantly reduced in CHOm- (0.24±0.11 nmol/min per mg of mitochondrial protein) compared with CHOm+ (3.21±0.66 nmol/min per mg of mitochondrial protein; P = 0.02) cells, whereas cytosolic SHMT activity was similar in CHOm- and CHOm+ cells (1.09±0.31 and 1.53±0.12 nmol/min per mg of cytosolic protein respectively; P = 0.57). In CHOm+ and CHOm- cells, the relative flux of glycine to serine measured with either [1-13C]- or [2-13C]-glycine was similar (CHOm-: 538±82 nmol/24 per mg of DNA; CHOm+: 616±88 nmol/24 h per mg of DNA; P = 0.42). In contrast, the relative flux of serine to glycine measured with [1-13C]serine was low in CHOm- cells (80±28 nmol/24 h per mg of DNA) compared with CHOm+ cells (3080±320 nmol/24 h per mg of DNA; P = 0.0001). The rate of glycine production determined by UA-2[1-13C]glycine dilution was lower in CHOm- (1200±200 nmol/24 h per mg of DNA) than CHOm+ (10200±1800 nmol/24 h per mg of DNA; P = 0.03) cells, whereas glycine utilization was similar in the two cell lines. Serine production was similar in the two cell lines but serine utilization was lower in CHOm- (3800±1200 μmol/24 h per mg of DNA) than CHOm+ (6600±1000 nmol/24 h per mg of DNA; P = 0.0002) cells. Increasing the serine concentration in the medium resulted in an increase in glycine production in CHOm+ but not in CHOm- cells. Intracellular studies with [1-13C]serine confirm the findings of decreased glycine production from serine. In CHO cells there is partitioning of intracellular serine and glycine metabolism. Our data support the hypothesis that mitochondrial SHMT is the primary pathway for serine into glycine interconversion.


2021 ◽  
Author(s):  
Philipp N. Spahn ◽  
Xiaolin Zhang ◽  
Qing Hu ◽  
Nathaniel K. Hamaker ◽  
Hooman Hefzi ◽  
...  

AbstractChinese Hamster Ovary (CHO) cells are the primary host used for manufacturing of therapeutic proteins. However, production instability of high-titer cell lines is a major problem and is associated with genome instability, as chromosomal aberrations reduce transgene copy number and decrease protein titer. We analyzed whole-genome sequencing data from 11 CHO cell lines and found deleterious single-nucleotide polymorphisms (SNPs) in DNA repair genes. Comparison with other mammalian cells confirmed DNA repair is compromised in CHO. Restoration of key DNA repair genes by SNP reversal or expression of intact cDNAs improved DNA repair and genome stability. Moreover, the restoration of LIG4 and XRCC6 in a CHO cell line expressing secreted alkaline phosphatase mitigated transgene copy loss and improved protein titer retention. These results show for the first time that correction of key DNA repair genes yields considerable improvements in stability and protein expression in CHO, and provide new opportunities for cell line development and a more efficient and sustainable production of therapeutic proteins.


PLoS ONE ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. e0241250
Author(s):  
Shanta Boddapati ◽  
Jason Gilmore ◽  
Kyle Boone ◽  
John Bushey ◽  
Jonathan Ross ◽  
...  

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Nathalie Veith ◽  
Holger Ziehr ◽  
Roderick A. F. MacLeod ◽  
Stella Marie Reamon-Buettner

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