Identification of regulatory motifs in the CHO genome for stable monoclonal antibody production
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Chinese hamster ovary (CHO) cell lines are widely used for therapeutic protein production. When a transgene is integrated into the genome of a CHO cell, the expression level is highly dependent on the site of integration because of positional effects such as gene silencing. To overcome negative positional effects and establish stable CHO cell lines with high productivity, several regulatory DNA elements are used in vector construction. Previously, we established the CHO DR1000L-4N cell line, a stable and high copy number Dhfr gene-amplified cell line. It was hypothesized that the chromosomal location of the exogenous gene-amplified region in the CHO DR1000L-4N genome contains regulatory motifs for stable protein production. Therefore, we isolated DNA regulatory motifs from the CHO DR1000L-4N cell line and determined whether these motifs act as an insulator. Our results suggest that stable expression of a transgene can be promoted by the CHO genome sequence, and it would be a powerful tool for therapeutic protein manufacturing.
KeywordsChinese hamster ovary cells Therapeutic antibody Insulator Epigenetics
This work was partly patented as Japan patent 4568378 and partly supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science. Authors also appreciate to Mr. Shuichi Kimura for detail discussion.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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