title: Genome-wide analysis of hepatic gene silencing in mammalian cell hybrids.
abstract: Silencing of tissue-specific gene expression in mammalian somatic cell hybrids is a well-documented epigenetic phenomenon which is both profound (involving a large number of genes) and enigmatic. Our aim was to utilize whole-genome microarray analyses to determine the true extent of gene silencing on a genomic level. By comparing gene expression profiles of hepatoma×fibroblast cell hybrids with those of parental cells, we have identified over 300 liver-enriched genes that are repressed at least 5-fold in the cell hybrids, the majority of which are repressed at least 10-fold. Also, we identify nearly 200 fibroblast-enriched genes that are repressed at least 5-fold. Silenced hepatic genes include several that encode transcription factors and proteins involved in signal transduction pathways. These data suggest that extensive reprogramming occurs in cell hybrids, leading to a nearly global (although not complete) loss of tissue-specific gene expression.
authors.affiliation: Department of Biological Sciences, Eastern Illinois University, 600 Lincoln Avenue, Charleston, IL 61920, USA. gabulla@eiu.edu
authors.forename: Gary A
authors.initials: GA
authors.lastname: Bulla
authors.forename: Quang
authors.initials: Q
authors.lastname: Luong
authors.forename: Sushma
authors.initials: S
authors.lastname: Shrestha
authors.forename: Sarah
authors.initials: S
authors.lastname: Reeb
authors.forename: Sharon
authors.initials: S
authors.lastname: Hickman
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D065150:Cellular Reprogramming / Q000235:genetics; D057890:Epigenomics; D005347:Fibroblasts / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006822:Hybrid Cells / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D015203:Reproducibility of Results; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D011506:Proteins; D014157:Transcription Factors