title: CMV promoter mutants with a reduced propensity to productivity loss in CHO cells.
abstract: The major immediate-early promoter and enhancer of the human cytomegalovirus (hCMV-MIE) is one of the most potent DNA elements driving recombinant gene expression in mammalian cells. Therefore, it is widely employed not only in research but also in large-scale industrial applications, e.g. for the production of therapeutic antibodies in Chinese hamster ovary cells (CHO). As we have reported previously, multi-site methylation of hCMV-MIE is linked to productivity loss in permanently transfected CHO cells lines. In particular, the cytosine located 179 bp upstream of the transcription start site (C-179) is frequently methylated. Therefore, our objective was to study whether mutation of C-179 and other cytosines within hCMV-MIE might lessen the instability of transgene expression. We discovered that the single mutation of C-179 to G can significantly stabilise the production of recombinant protein under control of hCMV-MIE in permanently transfected CHO cells.
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Moritz
authors.affiliation: Biomedical Center and Center for Integrated Protein Science Munich, Ludwig Maximilian University, Munich, Germany.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Becker
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Penzberg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Göpfert
mesh_terms: D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002999:Clone Cells; D006224:Cricetinae; D003412:Cricetulus; D003587:Cytomegalovirus / Q000235:genetics*; D017781:Genes, Immediate-Early; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis*
chemical_list: D011994:Recombinant Proteins