title: Genomic alterations in cultured human embryonic stem cells.
abstract: Cultured human embryonic stem cell (hESC) lines are an invaluable resource because they provide a uniform and stable genetic system for functional analyses and therapeutic applications. Nevertheless, these dividing cells, like other cells, probably undergo spontaneous mutation at a rate of 10(-9) per nucleotide. Because each mutant has only a few progeny, the overall biological properties of the cell culture are not altered unless a mutation provides a survival or growth advantage. Clonal evolution that leads to emergence of a dominant mutant genotype may potentially affect cellular phenotype as well. We assessed the genomic fidelity of paired early- and late-passage hESC lines in the course of tissue culture. Relative to early-passage lines, eight of nine late-passage hESC lines had one or more genomic alterations commonly observed in human cancers, including aberrations in copy number (45%), mitochondrial DNA sequence (22%) and gene promoter methylation (90%), although the latter was essentially restricted to 2 of 14 promoters examined. The observation that hESC lines maintained in vitro develop genetic and epigenetic alterations implies that periodic monitoring of these lines will be required before they are used in in vivo applications and that some late-passage hESC lines may be unusable for therapeutic purposes.
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Anirban
authors.initials: A
authors.lastname: Maitra
authors.forename: Dan E
authors.initials: DE
authors.lastname: Arking
authors.forename: Narayan
authors.initials: N
authors.lastname: Shivapurkar
authors.forename: Morna
authors.initials: M
authors.lastname: Ikeda
authors.forename: Victor
authors.initials: V
authors.lastname: Stastny
authors.forename: Keyaunoosh
authors.initials: K
authors.lastname: Kassauei
authors.forename: Guoping
authors.initials: G
authors.lastname: Sui
authors.forename: David J
authors.initials: DJ
authors.lastname: Cutler
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Sandii N
authors.initials: SN
authors.lastname: Brimble
authors.forename: Karin
authors.initials: K
authors.lastname: Noaksson
authors.forename: Johan
authors.initials: J
authors.lastname: Hyllner
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Schulz
authors.forename: Xianmin
authors.initials: X
authors.lastname: Zeng
authors.forename: William J
authors.initials: WJ
authors.lastname: Freed
authors.forename: Jeremy
authors.initials: J
authors.lastname: Crook
authors.forename: Suman
authors.initials: S
authors.lastname: Abraham
authors.forename: Alan
authors.initials: A
authors.lastname: Colman
authors.forename: Peter
authors.initials: P
authors.lastname: Sartipy
authors.forename: Sei-Ichi
authors.initials: S
authors.lastname: Matsui
authors.forename: Melissa
authors.initials: M
authors.lastname: Carpenter
authors.forename: Adi F
authors.initials: AF
authors.lastname: Gazdar
authors.forename: Mahendra
authors.initials: M
authors.lastname: Rao
authors.forename: Aravinda
authors.initials: A
authors.lastname: Chakravarti
mesh_terms: D018929:Cell Culture Techniques; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D004272:DNA, Mitochondrial / Q000737:chemistry; D004622:Embryo, Mammalian / Q000166:cytology*; D015894:Genome, Human / Q000235:genetics*; D006801:Humans; D009154:Mutation; D011401:Promoter Regions, Genetic; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D004272:DNA, Mitochondrial; D004247:DNA