title: Characterization of gene localization and accessibility in DHFR-amplified CHO cells.
abstract: Efficient transcription is critical for high yields of recombinant proteins by mammalian cells. We previously reported that dihydrofolate reductase (DHFR)-mediated gene amplification can augment transcriptional rates as well as increasing gene copy numbers in Chinese hamster ovary (CHO) cells.1 In an attempt to elucidate the mechanisms involved, we have employed several approaches to identify the epigenetic differences between cell clones with varying transcriptional rates. Transgene placement and accessibility varies between unrelated parental cell clones with differential transcriptional rates. However, we did not observe any apparent epigenetic differences between parental clones and their amplified progeny, indicating undiscovered regulatory mechanisms are responsible for the augmentation of transcriptional rates upon DHFR-mediated amplification.
authors.affiliation: Dept. of Chemical & Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Jiang
authors.forename: Susan T
authors.initials: ST
authors.lastname: Sharfstein
mesh_terms: D000107:Acetylation; D000818:Animals; D015139:Blotting, Southern; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics*; D018983:DNA Footprinting; D044127:Epigenesis, Genetic; D006657:Histones / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D006657:Histones; D004247:DNA; D013762:Tetrahydrofolate Dehydrogenase