Genomic alterations in cultured human embryonic stem cells.
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.
Maitra
Anirban
A
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.
Arking
Dan E
DE
Shivapurkar
Narayan
N
Ikeda
Morna
M
Stastny
Victor
V
Kassauei
Keyaunoosh
K
Sui
Guoping
G
Cutler
David J
DJ
Liu
Ying
Y
Brimble
Sandii N
SN
Noaksson
Karin
K
Hyllner
Johan
J
Schulz
Thomas C
TC
Zeng
Xianmin
X
Freed
William J
WJ
Crook
Jeremy
J
Abraham
Suman
S
Colman
Alan
A
Sartipy
Peter
P
Matsui
Sei-Ichi
S
Carpenter
Melissa
M
Gazdar
Adi F
AF
Rao
Mahendra
M
Chakravarti
Aravinda
A
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*
D004272:DNA, Mitochondrial; D004247:DNA