Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 313

The DOI matches its Crossref record; 45 of the 45 references it cites were found in a registry or an index.

A study of monoclonal antibody‐producing CHO cell lines: What makes a stable high producer?

Open access
Chusainow, Janet, Yang, Yuan Sheng, Yeo, Jessna H.M., Toh, Poh Choo, Asvadi, Parisa, Wong, Niki S.C., Yap, Miranda G.S.·2009·Biotechnology and Bioengineering
DOI 10.1002/bit.22158
Open this paper in CoChat — free account

Abstract

Generating stable, high‐producing cell lines for recombinant protein production requires an understanding of the potential limitations in the cellular machinery for protein expression. In order to increase our understanding of what makes a stable high producer, we have generated a panel of 17 recombinant monoclonal antibody expressing Chinese hamster ovary subclones (CHO‐mAb) with specific productivities ranging between 3 and 75 pg cell−1 day−1 using the dihydrofolate reductase (dhfr) expression system and compared the molecular features of these high‐ and low‐producer clones. The relative heavy chain (HC) and light chain (LC) transgene copy numbers and mRNA levels were determined using real‐time quantitative PCR (RT qPCR). We observed that not only higher transgene copy numbers and mRNA levels of both HC and LC were characteristic for the high‐producer clones as compared to the low‐producer clones but also a more favorable HC to LC transgene copy numbers ratio. By studying the long‐term stability of the CHO‐mAb subclones in the absence of methotrexate (MTX) selective pressure over 36 passages we observed a 35–92% decrease in volumetric productivity, primarily caused by a significant decrease in HC and LC mRNA levels with little change in the transgene copy numbers. Using Southern blot hybridization we analyzed the HC and LC transgene integration patterns in the host chromosome and their changes in course of gene amplification and long‐term culturing. We observed that MTX‐induced gene amplification caused chromosomal rearrangements resulting in clonal variability in regards to growth, productivity, and stability. No further obvious DNA rearrangements occurred during long‐term culturing in the absence of MTX, indicating that other mechanisms were responsible for the decreased transcription efficiency. Our results implicate that the amplified transgene sequences were arranged in tandem repeats potentially triggering repeat‐induced gene silencing. We hypothesize that the decline in transgene mRNA levels upon long‐term culturing without MTX was mainly caused by transgene silencing consequently leading to a loss in mAb productivity. The exact molecular mechanisms causing production instability are not yet fully understood. The herein described extensive characterization studies could help understand the limitations to high‐level, stable recombinant protein production and find ways to improving and accelerating the process for high‐producer cell line generation and selection. Biotechnol. Bioeng. 2009;102: 1182–1196. © 2008 Wiley Periodicals, Inc.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1002/bit.22158

Cites

45 of 45 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Cited by

See all 313

Metadata

Authors
Chusainow, J., Yang, Y. S., Yeo, J. H. M., Toh, P. C., Asvadi, P., Wong, N. S. C., & Yap, M. G. S.
Venue
Biotechnology and Bioengineering
Publisher
Wiley
Published
2008-10-31
Volume
102
Issue
4
Pages
1182-1196
ISSN
  • 0006-3592 (ISSN-L)
  • 1097-0290
DOI
10.1002/bit.22158
OpenAlex
W2121074166
Cited by
313
References
45
FWCI
5.21
Type
journal article
Language
en
Open access
bronze

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.