Creative Biogene’s gene editing CHO-K1 cells can save your precious time and effort with great performance in antibody production.

1. Antibody-Producing Cell Lines Development
Currently, stable cell lines have been widely used in various research applications, including recombinant protein
and antibody production, screening of experimental drugs, functional study of gene, assay development and so on.
Therapeutic antibodies are mainly produced in mammalian host cell lines including NS0 murine myeloma cells and
Chinese hamster ovary (CHO) cells [1]
. CHO cells are the predominant host used to produce therapeutic proteins.
About 70% of all recombinant proteins produced today are made in CHO cells [2]
. It is important to develop a stable
antibody-producing cell line to meet the high dosage requirement of therapeutic antibodies for the growing cancer
patient population.
Our scientists have years of experience at performing gene editing with CRISPR/Cas9, and have generated series
of gene knockout CHO-K1 cell lines developed by CRISPR/Cas9 system. Our gene editing CHO-K1 cells can save
your precious time and effort with great performance in antibody production.
We have a list of ready to use CHO-K1 cells targeting genes crucial in antibody production process.
1. Fut8 Knockout- Increasing Antibody-Dependent Cellular Cytotoxicity (ADCC)
Fut8 encodes an enzyme belonging to the family of fucosyltransferases. The product of this gene catalyzes the
transfer of fucose from GDP-fucose to N-linked type complex glycopeptides. FUT8(-/-) CHO-K1 cells which
increases antibody-dependent cellular cytotoxicity (ADCC) has been widely used as hosts for antibody production.
2. GS Knockout- Rapidly Selection of CHO-K1 Cell Lines for High Level Antibody Production
GS encodes an enzyme belongs to the glutamine synthetase family. Glutamine is an abundant amino acid, and is
important to the biosynthesis of several amino acids, pyrimidines, and purines. Mutations in this gene are
associated with congenital glutamine deficiency. Glutamine Synthetase (GS) Expression System can be used for
rapidly selection of CHO-K1 cell lines for high level antibody production.
3. Bax/Bak Knockout- Resistant to Apoptosis
Programmed cell death, which is required for the development and homeostasis of metazoans, includes
mechanisms such as apoptosis, autophagic cell death, and necrotic (or type III) death. Members of the Bcl2 family
regulate apoptosis, among which Bax and Bak act as a mitochondrial gateway. Bax/Bak double-knockout mice are
resistant to apoptosis [3]
.
Advantages
1. Rapidly selection of CHO cell lines using the Glutamine Synthetase (GS) Expression System for high level antibody
production
2. Increasing antibody-dependent cellular cytotoxicity (ADCC)
3. Excellent performance with high antibody production, high antibody quality, or a short timeline
Antibody-Producing Cell Line Product List
Cat. Product Name Target Gene Host Cell

2. CSC-RT0097 GS/Fut8 Knockout Cell Line-CHO-K1 GS/Fut8 CHO-K1
CSC-RT0103 GS/Bax/Bak1 Knockout Cell Line-CHO-K1 GS/Bax/Bak1 CHO-K1
CSC-RT0119 GS/BAX Knockout Cell Line-CHO-K1 GS/BAX CHO-K1
CSC-RT0125 GS Knockout Cell Line-CHO-K1 GS CHO-K1
References:
1. Xu N, Ou J, Gilani A K A, et al. High-level expression of recombinant IgG1 by CHO K1 platform[J]. Frontiers of
Chemical Science and Engineering, 2015, 9(3): 376-380.
2. Li F, Vijayasankaran N, Shen A, et al. Cell culture processes for monoclonal antibody production[C]//MAbs. Taylor &
Francis, 2010, 2(5): 466-479.
3. Arakawa S, Tsujioka M, Yoshida T, et al. Role of Atg5-dependent cell death in the embryonic development of Bax/Bak
double-knockout mice[J]. Cell Death & Differentiation, 2017.
Case Study I
CSC-RT0125 GS Knockout Cell Line-CHO-K1
1. Design gRNA targeting GS gene and construct knockout vector.
2. CHO-K1 cells were transfected with the construct and the cell pool was analyzed by Sanger sequencing.
3. Digest PCR products with our knockout detection (KOD) enzyme to select positive clones.
4. TA cloning and sequencing. A single clone containing a 32 bp deletion in allele 1 and allele 2 was carried forward (Fig.
1).
5. To assess loss of function, GS knockouts were grown in the presence or absence of increasing concentrations of
glutamine (Fig. 2).
Fig. 1 Sequencing verification of TA cloning

3. Fig. 2 L-
glutamine Dependence of CHO-K1 (GS-/-)
GS knockouts were unable to grow in the absence of glutamine. However, growth improved in the presence of
increasing concentrations of glutamine, thereby indicating a functional loss in the GS knockout cell line.
Case Study II
CSC-RT0097 GS/Fut8 Knockout Cell Line-CHO-K1
1. Design gRNA targeting Fut8 gene and construct knockout vector.
2. CHO-K1-GS-/- cells (CSC-RT0125) were transfected with the construct and the cell pool was analyzed by Sanger
sequencing. (Fig. 1)
3. Digest PCR products with our KOD enzyme to select positive clones. (Fig. 2)
4. Individual clones were Sanger sequenced to select for homozygous knock-out indels of Fut8. (Fig. 3)
Fig. 1 The
sequencing chromatogram of PCR product for positive clone
Fig. 2 Digestion of PCR products with KOD enzyme

4. KOD enzyme can recognize the nicks resulted from the knocking out process and will therefore cut such PCR
products into two bands.
Fig. 3 Sequencing verification of TA cloning
(11 bp deletion in allele 1 and 1 bp insertion in allele 2)
However, whether the changes in the circadian cycle can lead to human cancer? Currently, it is not clear whether changes in
circadian rhythms will lead to changes in UPR and whether this will, in turn, lead to cancer. However, these results can help
clinicians improve the effectiveness of current cancer treatments. For example, whether it is possible to treat cancers on a
regular basis if taking medications at specific times of the day, may be possible to get a better therapeutic effect on cancer and
less toxicity on normal cells.
https://www.creative-biogene.com/blog/index.php/2018/04/24/tumor-cells-manipulate-biochronometer-with-unfolded-
protein-response-to-immunize-themselves/