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Yamano-Adachi N, Hata H, Nakanishi Y, Omasa T. Effects of genome instability of parental CHO cell clones on chromosome number distribution and recombinant protein production in parent-derived subclones. J Biosci Bioeng 2024; 137:54-63. [PMID: 37981489 DOI: 10.1016/j.jbiosc.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/11/2023] [Accepted: 10/16/2023] [Indexed: 11/21/2023]
Abstract
Chinese hamster ovary (CHO) cells are the de facto standard host cells for biopharmaceuticals, and there is great interest in developing methods for constructing stable production cell lines. In this study, clones with a wide chromosome number distribution were selected from isolated antibody-producing strains, and subclones obtained from these clones were evaluated. The transgene copy number varied between the subclones. Even among subclones with similar copy numbers of antibody genes and maintained insertion sites, clones with different productivity were generated. Although the chromosome number distribution differed between these subclones, there was no correlation between the variability in chromosome number after cloning (genome instability) and productivity. Most of the subclones obtained from a parental strain with a wide chromosome number had the same wide chromosome number distribution as the parental strain. Less frequently, cells with less variation (remaining in one distribution) in chromosome number were isolated from cells with a wide chromosome number distribution, from which subclones with less variation in chromosome number were obtained when subcloning was performed again. These results imply that the characteristics of clones with chromosomal instability are inherited by subclones, and thus provide a better understanding of cell line stability/instability.
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Affiliation(s)
- Noriko Yamano-Adachi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hirofumi Hata
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuto Nakanishi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Omasa
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Yamano-Adachi N, Nakanishi Y, Tanaka W, Lai Y, Yamazaki M, Zenner L, Hata H, Omasa T. Artificial induction of chromosome aneuploidy in CHO cells alters their function as host cells. Biotechnol Bioeng 2023; 120:659-673. [PMID: 36385243 DOI: 10.1002/bit.28289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/06/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Chinese hamster ovary (CHO) cells are major host cells for biopharmaceuticals. During culture, the chromosome number of CHO cells alters spontaneously. Here, we investigated the effects of artificial changes in the chromosome number on productivity. When cell fusion between antibody-producing CHO-K1-derived cells was induced, we observed a wide range of aneuploidy that was not detected in controls. In particular, antibody productivities were high in clone-derived cell populations that retained a diverse chromosome number distribution. We also induced aneuploid cells using 3-aminobenzamide that causes chromosome non-disjunction. After induction of aneuploidy by 3-aminobenzamide, cells with an increased chromosome number were isolated, but cells with a decreased chromosome number could not be isolated. When antibody expression vectors were introduced into these isolated clones, productivity tended to increase in cells with an increased chromosome number. Further analysis was carried out by focusing on clone 5E8 with an average chromosome number of 37. When 5E8 cells were used as host, the productivity of multiple antibodies, including difficult-to-express antibodies, was improved compared with CHO-K1 cells. The copies of exogenous genes integrated into the genome were significantly increased in 5E8 cells. These findings expand the possibilities for host cell selection and contribute to the efficient construction of cell lines for recombinant protein production.
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Affiliation(s)
- Noriko Yamano-Adachi
- Graduate School of Engineering, Osaka University, Osaka, Japan.,Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan
| | - Yuto Nakanishi
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Wataru Tanaka
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - YuanShan Lai
- Graduate School of Advanced Technology and Science, Tokushima University, Tokushima, Japan
| | | | - Laura Zenner
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Hirofumi Hata
- Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Takeshi Omasa
- Graduate School of Engineering, Osaka University, Osaka, Japan.,Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan
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Horie M, Yamano-Adachi N, Kawabe Y, Kaneoka H, Fujita H, Nagamori E, Iwai R, Sato Y, Kanie K, Ohta S, Somiya M, Ino K. Recent advances in animal cell technologies for industrial and medical applications. J Biosci Bioeng 2022; 133:509-514. [DOI: 10.1016/j.jbiosc.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/25/2022]
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Spahn PN, Zhang X, Hu Q, Lu H, Hamaker NK, Hefzi H, Li S, Kuo CC, Huang Y, Lee JC, Davis AJ, Ly P, Lee KH, Lewis NE. Restoration of DNA repair mitigates genome instability and increases productivity of Chinese hamster ovary cells. Biotechnol Bioeng 2022; 119:963-982. [PMID: 34953085 PMCID: PMC8821244 DOI: 10.1002/bit.28016] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/18/2021] [Indexed: 11/11/2022]
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.
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Affiliation(s)
- Philipp N. Spahn
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego School of Medicine, San Diego, La Jolla, CA 92093
| | - Xiaolin Zhang
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711
| | - Qing Hu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Huiming Lu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nathaniel K. Hamaker
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711
| | - Hooman Hefzi
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Shangzhong Li
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Chih-Chung Kuo
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Yingxiang Huang
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093
| | - Jamie C. Lee
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Anthony J. Davis
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Peter Ly
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Kelvin H. Lee
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, These authors jointly supervised this work: Kelvin H. Lee, , 302-831-0344, Nathan E. Lewis, , 858-997-5844
| | - Nathan E. Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego School of Medicine, San Diego, La Jolla, CA 92093, Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, These authors jointly supervised this work: Kelvin H. Lee, , 302-831-0344, Nathan E. Lewis, , 858-997-5844
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Yamano-Adachi N, Ogata N, Tanaka S, Onitsuka M, Omasa T. Characterization of Chinese hamster ovary cells with disparate chromosome numbers: Reduction of the amount of mRNA relative to total protein. J Biosci Bioeng 2019; 129:121-128. [PMID: 31303495 DOI: 10.1016/j.jbiosc.2019.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/06/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022]
Abstract
Chromosomes in Chinese hamster ovary (CHO) cells are labile. We have shown that high-chromosome-number CHO cells have greater potential to become robust producers of recombinant proteins. One explanation being the increase in transgene integration sites. However, high-chromosome-number cell clones produce more IgG3 following culture of single-cell clones, even under conditions that yield the same number of integrations as cells with normal chromosome numbers. Here, we characterized high-chromosome-number cells by transcriptome analysis. RNA standards were used to normalize transcriptomes of cells that had different chromosome numbers. Our results demonstrate that the mRNA ratio of β-actin and many other genes in high-chromosome-number cells to that in normal-chromosome-number cells per cell (normalized to RNA standards) was smaller than the equivalent genomic size and cell volume ratios. Many genes encoding membrane proteins are more highly expressed in high-chromosome-number cells, probably due to differences in cell size caused by the increase in chromosomes. In addition, genes related to histone modification and lipid metabolism are differentially expressed. The reduced transcript level required per protein produced in total and the different intracellular signal transductions might be key factors for antibody production.
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Affiliation(s)
- Noriko Yamano-Adachi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Norichika Ogata
- Nihon BioData Corporation, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan.
| | - Sho Tanaka
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Masayoshi Onitsuka
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima, Tokushima 770-8506, Japan.
| | - Takeshi Omasa
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Yang B, Zhou J, Zhao H, Wang A, Lei Y, Xie Q, Xiong S. Study of the mechanism for increased protein expression via transcription potency reduction of the selection marker. Bioprocess Biosyst Eng 2019; 42:799-806. [PMID: 30730009 DOI: 10.1007/s00449-019-02083-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 01/24/2019] [Indexed: 01/02/2023]
Abstract
Stable transfection of mammalian cells using various expression cassettes for exogenous gene expression has been well established. The impact of critical factors in these cassettes, such as promoter and enhancer elements, on recombinant protein production in mammalian cells has been studied extensively to optimize the expression efficiency. However, few studies on the correlation between the strength of selection marker and the expression of gene of interest (GOI) have been reported. Here we investigated the correlation between the strength of a widely used selection marker, glutamine synthetase (GS) gene, and gene of interest in which the expression of GOI is driven by mouse cytomegalovirus (mCMV) major immediate early (MIE) promoter whereas the expression of GS is controlled by SV40E (Simian vacuolating virus 40E) promoter. We used a green fluorescent protein and the adalimumab antibody (heavy and light chain) as two distinct examples for the gene of interest. We then decreased the expression of GS gene by engineering a specific region of its SV40E promoter in these expression cassettes. By comparing the expression of GS and GOI at transcription and translation level before and after the SV40E promoter was weakened, we found that lower GS expression due to weaker SV40E transcription correlated well with the higher expression of recombinant proteins, mainly by increasing the copy number of GS and GOI integration into host cell genome.
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Affiliation(s)
- Bin Yang
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China
| | - Jiatao Zhou
- Sunshine Lake Pharma Co., Ltd., Zhen An Road, Dongguan, 523867, People's Republic of China
| | - Hui Zhao
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China
| | - Anling Wang
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China
| | - Yuanjun Lei
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China
| | - Qiuling Xie
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China
| | - Sheng Xiong
- Department of Cell Biol, Institute of Biomedicine & National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, 730 Building of Biology, 601 W Huangpu Ave, Guangzhou, 510630, Guangdong, People's Republic of China.
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Soo BPC, Tay J, Ng S, Ho SCL, Yang Y, Chao SH. Correlation Between Expression of Recombinant Proteins and Abundance of H3K4Me3 on the Enhancer of Human Cytomegalovirus Major Immediate-Early Promoter. Mol Biotechnol 2017; 59:315-322. [DOI: 10.1007/s12033-017-0019-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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