title: Transcriptome and proteome profiling to understanding the biology of high productivity CHO cells.
abstract: A combined transcriptome and proteome analysis was carried out to identify key genes and proteins differentially expressed in Chinese hamster ovary (CHO) cells producing high and low levels of dhfr-GFP fusion protein. Comparison of transcript levels was performed using a proprietary 15K CHO cDNA microarray chip, whereas proteomic analysis was performed using iTRAQ quantitative protein profiling technique. Microarray analysis revealed 77 differentially expressed genes, with 53 genes upregulated and 24 genes downregulated. Proteomic analysis gave 75 and 80 proteins for the midexponential and stationary phase, respectively. Although there was a general lack of correlation between mRNA levels and quantitated protein abundance, results from both datasets concurred on groups of proteins/genes based on functional categorization. A number of genes (20%) and proteins (45 and 23%) were involved in processes related to protein biosynthesis. We also identified three genes/proteins involved in chromatin modification. Enzymes responsible for opening up chromatin, Hmgn3 and Hmgb1, were upregulated whereas enzymes that condense chromatin, histone H1.2, were downregulated. Genes and proteins that promote cell growth (Igfbp4, Ptma, S100a6, and Lgals3) were downregulated, whereas those that deter cell growth (Ccng2, Gsg2, and S100a11) were upregulated. Other main groups of genes and proteins include carbohydrate metabolism, signal transduction, and transport. Our findings show that an integrated genomic and proteomics approach can be effectively utilized to monitor transcriptional and posttranscriptional events of mammalian cells in culture.
authors.affiliation: Bioprocessing Technology Institute, 20 Biopolis Way, #06-01 Centros, Singapore, 138668. peter_morin@bti.a-star.edu.sg
authors.forename: Peter Morin
authors.initials: PM
authors.lastname: Nissom
authors.forename: Arleen
authors.initials: A
authors.lastname: Sanny
authors.forename: Yee Jiun
authors.initials: YJ
authors.lastname: Kok
authors.forename: Yeo Thong
authors.initials: YT
authors.lastname: Hiang
authors.forename: Song Hui
authors.initials: SH
authors.lastname: Chuah
authors.forename: Tan Kher
authors.initials: TK
authors.lastname: Shing
authors.forename: Yih Yean
authors.initials: YY
authors.lastname: Lee
authors.forename: Kathy Tin Kam
authors.initials: KT
authors.lastname: Wong
authors.forename: Wei-Shou
authors.initials: WS
authors.lastname: Hu
authors.forename: Miranda Yap Gek
authors.initials: MY
authors.lastname: Sim
authors.forename: Robin
authors.initials: R
authors.lastname: Philp
mesh_terms: D000818:Animals; D016466:CHO Cells / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D023281:Genomics; D049452:Green Fluorescent Proteins / Q000096:biosynthesis*; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000235:genetics* / Q000378:metabolism*; D040901:Proteomics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis*; D014158:Transcription, Genetic
chemical_list: D020543:Proteome; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D013762:Tetrahydrofolate Dehydrogenase