title: Transcriptome and proteome analysis of Chinese hamster ovary cells under low temperature and butyrate treatment.
abstract: Recombinant Chinese hamster ovary (CHO) cells selected for high productivity are capable of secreting immunoglobulin G (IgG) molecules at a level that rivals plasma cells in vivo. Following butyrate treatment at 33 degrees C, further increases in productivity are observed. To better understand the mechanisms by which this increased productivity is incurred, the transcriptional response of an antibody-producing cell line undergoing these treatments was investigated using oligo-DNA microarrays. Using distance calculations, more than 900 genes were identified as kinetically differentially expressed between the butyrate-treated 33 degrees C culture and the untreated culture. Furthermore, transcript levels of the heavy and light chain IgG genes increased following treatment. Using stable isotope labeling (SILAC), the secretion rate of IgG was investigated by tracking the decay of the isotope label upon switching to unlabeled medium. Both treated and untreated cultures exhibited very similar IgG secretion kinetics. In contrast, the intracellular IgG content was found to be elevated following treatment. This result suggests that increased productivity under treatment is attributable to elevated cellular secretory capacity, rather than shorter holding times in the secretory pathway. This hypothesis is further supported by the results of gene set enrichment analysis (GSEA), which revealed that elements of the secretory pathway, including Golgi apparatus, cytoskeleton protein binding and small GTPase-mediated signal transduction are enriched and thus may play a role in the increased recombinant protein production observed under butyrate treatment at 33 degrees C.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455-0132, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Kantardjieff
authors.forename: Nitya M
authors.initials: NM
authors.lastname: Jacob
authors.forename: Joon Chong
authors.initials: JC
authors.lastname: Yee
authors.forename: Eyal
authors.initials: E
authors.lastname: Epstein
authors.forename: Yee-Jiun
authors.initials: YJ
authors.lastname: Kok
authors.forename: Robin
authors.initials: R
authors.lastname: Philp
authors.forename: Michael
authors.initials: M
authors.lastname: Betenbaugh
authors.forename: Wei-Shou
authors.initials: WS
authors.lastname: Hu
mesh_terms: D000818:Animals; D002087:Butyrates / Q000008:administration & dosage*; D016466:CHO Cells / Q000187:drug effects / Q000378:metabolism*; D006224:Cricetinae / Q000378:metabolism*; D003412:Cricetulus; D020869:Gene Expression Profiling / Q000379:methods; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000235:genetics; D020543:Proteome / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D002087:Butyrates; D007074:Immunoglobulin G; D020543:Proteome; D011994:Recombinant Proteins; D014157:Transcription Factors