Genomic Analysis of hESC Pedigrees Identifies De Novo Mutations and Enables Determination of the Timing and Origin of Mutational Events

• Published in: Cell reports (Cambridge) 2013-09, Vol.4 (6), p.1288-1302
• Main Authors: Ben-Yosef, Dalit, Boscolo, Francesca S., Amir, Hadar, Malcov, Mira, Amit, Ami, Laurent, Louise C.
• Format: Article
• Language: English
• Subjects: Cell Growth Processes - genetics; Cell Line; Embryonic Stem Cells - cytology; Embryonic Stem Cells - pathology; Embryonic Stem Cells - physiology; Genomics - methods; Humans; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - pathology; Induced Pluripotent Stem Cells - physiology; Mutation; Pedigree; Pluripotent Stem Cells - cytology; Pluripotent Stem Cells - pathology; Pluripotent Stem Cells - physiology
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2013.08.009

Given the association between mutational load and cancer, the observation that genetic aberrations are frequently found in human pluripotent stem cells (hPSCs) is of concern. Prior studies in human induced pluripotent stem cells (hiPSCs) have shown that deletions and regions of loss of heterozygosity (LOH) tend to arise during reprogramming and early culture, whereas duplications more frequently occur during long-term culture. For the corresponding experiments in human embryonic stem cells (hESCs), we studied two sets of hESC lines: one including the corresponding parental DNA and the other generated from single blastomeres from four sibling embryos. Here, we show that genetic aberrations observed in hESCs can originate during preimplantation embryo development and/or early derivation. These early aberrations are mainly deletions and LOH, whereas aberrations arising during long-term culture of hESCs are more frequently duplications. Our results highlight the importance of close monitoring of genomic integrity and the development of improved methods for derivation and culture of hPSCs. [Display omitted] •Subchromosomal deletions and LOH most commonly occur during derivation of hESC lines•Genetic duplications arise most frequently during long-term passage of hESC lines•The timing of duplications and deletions/LOH are similar in hESCs and hiPSCs•There is no detectable parent-of-origin bias for de novo CNVs identified in hESCs Human embryonic stem cells (hESCs) are potential sources of cells for transplantation therapy. However, given the association between mutations and cancer, the frequency of genetic aberrations observed in hESCs is concerning. Using unique pedigrees of hESC lines, Laurent and colleagues now find that aberrations that occur during cell-line derivation are mainly deletions and loss of heterozygosity, whereas duplications arise more commonly during long-term culture. These results highlight the need for improved methods for derivation and culture that preserve the genetic integrity of hESCs.