"Quantitative Proteomics and CRISPR/Cas9 Editing Reveal UPR‐Mediated Control of Immunoglobulin Homeostasis in Hybridomas"

Rubing Zou*, Xinying Lu*, Ying Liu, Peiyu Yang, Shuo Sun, Yihua Liu, Yinyuan Mo, Guonian Zhu, Jae Seong Lee‡, Yirong Guo‡. Advanced Science 13(17): e14140.

Despite their tremendous economic value, monoclonal antibodies are often compromised by the loss of immunoglobulin (Ig) chains, which disrupts antibody homeostasis and quality control. Through subclone screening and characterization, we identified that the loss of Ig production impaired the recognit..

"CRISPR screen-based mammalian cell engineering for complex biotherapeutics"

Sung Wook Shin*, Gyun Min Lee, Jae Seong Lee‡. Trends in Biotechnology Epub ahead of print S0167-7799(25): 00464-0.

The rise of complex biotherapeutics has introduced bottlenecks in production using mammalian cells. Clustered regularly interspaced short palindromic repeats (CRISPR)-based screens enable unbiased discovery of engineering targets that mitigate biomanufacturing-relevant constraints. This forum gives ..

"Recombinase-Mediated Cassette Exchange-Based CRISPR Activation Screening Identifies Hyperosmotic Stress-Resistant Genes in Chinese Hamster Ovary Cells"

Minhye Baek*, Seokchan Kweon, Yujin Kim, Nathan E Lewis, Jae Seong Lee, Gyun Min Lee‡. ACS Synthetic Biology 14(8): 3116-3126.

Chinese hamster ovary (CHO) cells are ubiquitously used for therapeutic protein production. However, fed-batch culture, typically used for large-scale production, often induces hyperosmotic stress, negatively impacting cell growth and productivity. To identify genes conferring resistance to hyperosm..

"Comprehensive genome-scale CRISPR knockout screening of CHO cells"

Sung Wook Shin*, Su Hyun Kim*, Aghiles Gasselin, Gyun Min Lee‡, Jae Seong Lee‡. Scientific Data 12(1): 71.

Chinese hamster ovary (CHO) cells play a pivotal role in the production of recombinant therapeutics. In the present study, we conducted a genome-scale pooled CRISPR knockout (KO) screening using a virus-free, recombinase-mediated cassette exchange-based platform in CHO-K1 host and CHO-K1 derived rec..

"Unraveling productivity-enhancing genes in Chinese hamster ovary cells via CRISPR activation screening using recombinase-mediated cassette exchange system"

Minhye Baek*, Che Lin Kim, Su Hyun Kim, Karen Julie la Cour Karottki, Hooman Hefzi, Lise Marie Grav, Lasse Ebdrup Pedersen, Nathan E Lewis, Jae Seong Lee‡, Gyun Min Lee‡. Metabolic Engineering 87: 11-20.

Chinese hamster ovary (CHO) cells, which are widely used for therapeutic protein production, have been genetically manipulated to enhance productivity. Nearly half of the genes in CHO cells are silenced, which are promising targets for CHO cell engineering. To identify novel gene targets among the s..

"Context-dependent genomic locus effects on antibody production in recombinant Chinese hamster ovary cells generated through random integration"

Hyun Jee Woo*, Jaehoon Kim*, Seul Mi Kim, Dongwoo Kim, Jae Yun Moon, Daechan Park‡, Jae Seong Lee‡. Computational and Structural Biotechnology Journal 23: 1654-1665.

High-yield production of therapeutic protein using Chinese hamster ovary (CHO) cells requires stable cell line development (CLD). CLD typically uses random integration of transgenes; however, this results in clonal variation and subsequent laborious clone screening. Therefore, site-specific integrat..

"Revisiting the impact of genomic hot spots: C12orf35 locus as a hot spot and engineering target"

Kyuhee Cho*, Jae Seong Lee‡. Biotechnology and Bioengineering 121(11): 3642-3649.

Traditional Chinese hamster ovary (CHO) cell line development is based on random integration (RI) of transgene that causes clonal variation and subsequent large-scale clone screening. Therefore, site-specific integration (SSI) of transgenes into genomic hot spots has recently emerged as an alternati..

"A precise and sustainable doxycycline-inducible cell line development platform for reliable mammalian cell engineering with gain-of-function mutations"

Sung Wook Shin*, Honggi Min, Jiwon Kim, Jae Seong Lee‡. Metabolic Engineering 86: 12-28.

For mammalian synthetic biology research, multiple orthogonal and tunable gene expression systems have been developed, among which the tetracycline (Tet)-inducible system is a key tool for gain-of-function mutations. Precise and long-lasting regulation of genetic circuits is necessary for the effect..

"Application of CRISPR/Cas9 Genome Editing to Improve Recombinant Protein Production in CHO Cells"

Lise Marie Grav‡, Johan Blatt Rojek, Karen Julie la Cour Karottki, Jae Seong Lee, Helene Faustrup Kildegaard. Heterologous Protein Production in CHO Cells. Methods in Molecular Biology 2853: 49-69.

Genome editing has become an important aspect of Chinese hamster ovary (CHO) cell line engineering for improving the production of recombinant protein therapeutics. Currently, the engineering focus is directed toward expanding product diversity while controlling and improving product quality and yie..

"Genome-wide CRISPR/Cas9 screening unveils a novel target ATF7IP–SETDB1 complex for enhancing difficult-to-express protein production"

Su Hyun Kim*, Jong-Ho Park, Sungwook Shin, Seunghyeon Shin, Dahyun Chun, Yeon-Gu Kim, Jiseon Yoo, Weon-Kyoo You, Jae Seong Lee‡, Gyun Min Lee‡. ACS Synthetic Biology 13(2): 634-647.

With the emerging novel biotherapeutics that are typically difficult-to-express (DTE), improvement is required for high-yield production. To identify novel targets that can enhance DTE protein production, we performed genome-wide fluorescence-activated cell sorting (FACS)-based clustered regularly i..

"Knockout of the lysosomal membrane protein, LAMP2C, improves transient gene expression in HEK293 cells via increased intracellular plasmid availability"

Dongwoo Kim*, Seul Mi Kim*, Jaejin Lee, Jiwon Kim, Jae Seong Lee‡. Biotechnology Journal 19(1): 2300017.

Plasmid-based transfection can be used in many applications such as transient gene expression (TGE)-based therapeutic protein production. These applications preferentially require maximization of intracellular plasmid availability. Here, we applied a lysosome engineering approach to alleviate lysoso..

"Identification of hyperosmotic stress-responsive genes in Chinese hamster ovary cells via genome-wide virus-free CRISPR/Cas9 screening"

Su Hyun Kim*, Seunghyeon Shin, Minhye Baek, Kai Xiong, Karen Julie la Cour Karottki, Hooman Hefzi, Lise Marie Grav, Lasse Ebdrup Pedersen, Helene Faustrup Kildegaard, Nathan E Lewis, Jae Seong Lee‡, Gyun Min Lee‡. Metabolic Engineering 80: 66-77.

Chinese hamster ovary (CHO) cells are the preferred mammalian host cells for therapeutic protein production that have been extensively engineered to possess the desired attributes for high-yield protein production. However, empirical approaches for identifying novel engineering targets are laborious..

"Implementation of ubiquitous chromatin opening elements as artificial integration sites for CRISPR/Cas9-mediated knock-in in mammalian cells"

Seul Mi Kim*, Jaejin Lee, Jae Seong Lee‡. Engineering in Life Sciences 23(4): e2200047.

CRISPR/Cas9-mediated targeted gene integration (TI) has been used to generate recombinant mammalian cell lines with predictable transgene expression. Identifying genomic hot spots that render high and stable transgene expression and knock-in (KI) efficiency is critical for fully implementing TI-medi..

"Limitations of the plasmid-based Cas9-zinc finger fusion system for homology-directed knock-in in Chinese hamster ovary cells"

Dongwoo Kim*, Jae Seong Lee‡. Biotechnology and Bioprocess Engineering 28(2): 289-299.

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been used for the insertion of large transgenes into Chinese hamster ovary cells via co-transfection of a Cas9/guide RNA expression vector and donor plasmid. The Cas9 protein includes ..

"Hybrid cell line development system utilizing site-specific integration and methotrexate-mediated gene amplification in Chinese hamster ovary cells"

Honggi Min*, Seul Mi Kim, Dongwoo Kim, Solhwi Lee, Sumin Lee, Jae Seong Lee‡. Frontiers in Bioengineering and Biotechnology 10: 977193.

Site-specific integration has emerged as a promising strategy for streamlined and predictable Chinese hamster ovary (CHO) cell line development (CLD). However, the low specific productivity of the targeted integrants limits their practical application. In this study, we developed a hybrid CLD platfo..