@article{c3d023e5a826455695234ee21ff20ad2,
title = "Restoration of DNA repair mitigates genome instability and increases productivity of Chinese hamster ovary cells",
abstract = "Chinese hamster ovary (CHO) cells are the primary host for manufacturing of therapeutic proteins. However, productivity loss is a major problem and is associated with genome instability, as chromosomal aberrations reduce transgene copy number and decrease protein expression. We analyzed whole-genome sequencing data from 11 CHO cell lines and found deleterious single-nucleotide variants in DNA repair genes. Comparison with primary Chinese hamster cells confirmed DNA repair to be compromised in CHO. Correction of key DNA repair genes by single-nucleotide variant reversal or expression of intact complementary DNAs successfully improved DNA repair and mitigated karyotypic instability. Moreover, overexpression of intact copies 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 that correction of DNA repair genes yields improvements in genome stability in CHO, and provide new opportunities for cell line development for sustainable protein expression.",
keywords = "CHO, DNA repair, cell line instability, protein expression",
author = "Spahn, {Philipp N.} and Xiaolin Zhang and Qing Hu and Huiming Lu and Hamaker, {Nathaniel K.} and Hooman Hefzi and Shangzhong Li and Kuo, {Chih Chung} and Yingxiang Huang and Lee, {Jamie C.} and Davis, {Anthony J.} and Peter Ly and Lee, {Kelvin H.} and Lewis, {Nathan E.}",
note = "Funding Information: We would like to express our gratitude to George Yerganian for sharing primary Chinese hamster tissue. We thank Bj?rn Voldborg and Alexandra Hoffmeyer for sharing cell lines and for RNA sequencing services, and Nicole Borth for sharing metaphase preparation protocols. We thank Mojtaba Samoudi for assistance with fibroblast isolation. We thank Francisco Diaz, Jennifer Santini and Marcy Erb for technical assistance. We also thank Philip Gordts for constructive feedback, and John Ruano-Salguero and Jong Youn Baik for comments on the manuscript. This study was supported by NIGMS (R35 GM119850, NEL), the Novo Nordisk Foundation (NNF20SA0066621, NEL), NSF (grants 1736123 and 1412365, KHL), NIH (CA162804 and GM047251, AJD). Laser-scanning confocal microscopy was supported by NINDS P30 NS047101. Funding Information: We would like to express our gratitude to George Yerganian for sharing primary Chinese hamster tissue. We thank Bj{\o}rn Voldborg and Alexandra Hoffmeyer for sharing cell lines and for RNA sequencing services, and Nicole Borth for sharing metaphase preparation protocols. We thank Mojtaba Samoudi for assistance with fibroblast isolation. We thank Francisco Diaz, Jennifer Santini and Marcy Erb for technical assistance. We also thank Philip Gordts for constructive feedback, and John Ruano‐Salguero and Jong Youn Baik for comments on the manuscript. This study was supported by NIGMS (R35 GM119850, NEL), the Novo Nordisk Foundation (NNF20SA0066621, NEL), NSF (grants 1736123 and 1412365, KHL), NIH (CA162804 and GM047251, AJD). Laser‐scanning confocal microscopy was supported by NINDS P30 NS047101. Publisher Copyright: {\textcopyright} 2021 Wiley Periodicals LLC.",
year = "2022",
month = mar,
doi = "10.1002/bit.28016",
language = "English (US)",
volume = "119",
pages = "963--982",
journal = "Biotechnology and Bioengineering",
issn = "0006-3592",
publisher = "Wiley-VCH Verlag",
number = "3",
}