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Application of microRNA Targeted 3'UTRs to Repress DHFR Selection Marker Expression for Development of Recombinant Antibody Expressing CHO Cell Pools

Jossé, Lyne, Zhang, Lin, Smales, Christopher Mark (2018) Application of microRNA Targeted 3'UTRs to Repress DHFR Selection Marker Expression for Development of Recombinant Antibody Expressing CHO Cell Pools. Biotechnology Journal, 13 (10). Article Number 1800129. ISSN 1860-6768. (doi:10.1002/biot.201800129) (KAR id:68777)

Abstract

The dihydrofolate reductase (DHFR) system is used for the selection of recombinant Chinese hamster ovary (CHO) cell lines using the inhibitor methotrexate (MTX). During clonal selection, endogenous DHFR expression, and resistance to MTX allows the selection of cells expressing sufficient DHFR to survive. Here, the authors describe a novel vector platform for the DHFR system, whereby addition of a synthetic 3′UTR destabilizes DHFR expression. miRs ability to negatively regulate gene expression by their near-complementary binding to the 3′UTR region of transcripts are harnessed. From the literature, the authors identified let-7f as a highly abundant, invariant miR in CHO cells. Three 3′UTR targets of the let-7f miR are then cloned in the DHFR host 3′UTR to determine the impact on gene expression (HMGA2 3′UTR sequence 1, 2, and 3). Using luciferase as a reporter, the authors show down-regulation of luciferase activity is mediated by the nature of the 3′UTR and its ability to bind let-7f. The same 3′UTRs downstream of the DHFR gene to show this also results in reduced transcript amounts are then applied. Finally, the authors applied this methodology to generate stable DG44-derived cell pools expressing a model monoclonal antibody (mAb), demonstrating this approach can be used for the selection of antibody-producing cells with low MTX concentrations.

Item Type: Article
DOI/Identification number: 10.1002/biot.201800129
Subjects: Q Science
Q Science > QR Microbiology
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Lyne Josse
Date Deposited: 23 Aug 2018 13:47 UTC
Last Modified: 31 Oct 2023 12:46 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/68777 (The current URI for this page, for reference purposes)

University of Kent Author Information

Jossé, Lyne.

Creator's ORCID:
CReDIT Contributor Roles:

Smales, Christopher Mark.

Creator's ORCID: https://orcid.org/0000-0002-2762-4724
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