title: Genome modification in human embryonic stem cells.
abstract: Induced pluripotent stem cell (iPSC) technology has emerged as the most promising method for generating patient-specific human embryonic stem (ES) cells and adult stem cells (Takahashi et al., 2007, Cell 131:861-872; Wernig et al., 2007, Nature 448:318-324; Park et al., 2008, Nature 451:141-146). So far, most studies of direct reprogramming have been done by using lentiviruses/retroviruses encoding the reprogramming factors. This represents a major limitation to therapeutic applications since viral integration in the host genome increases the risk of tumorigenicity, and low-level residual expression of reprogramming factors may alter the differentiation potential of the human iPSCs (hiPSCs). As a result, more attention has been paid to developing new techniques to manipulate the human genome, with the goal of making safer hiPSCs that have fewer or no lesions or alterations in the genome. Additionally, the efficiency of reprogramming and of homologous recombination in gene therapy must be improved, if iPSC technology is to be a viable tool in regenerative medicine. Here, we summarize the recent developments in human genome manipulation for generating hiPSCs and advances in homologous recombination for gene targeting.
authors.affiliation: Stowers Medical Institute, Harvard Stem Cell Institute, Center for Regenerative Medicine, Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. totenzen@gmail.com
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Tenzen
authors.forename: Filip
authors.initials: F
authors.lastname: Zembowicz
authors.forename: Chad A
authors.initials: CA
authors.lastname: Cowan
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements; D053595:Embryonic Stem Cells / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting; D015316:Genetic Therapy / Q000009:adverse effects / Q000379:methods*; D005822:Genetic Vectors; D015894:Genome, Human; D042822:Genomic Instability; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D039904:Pluripotent Stem Cells / Q000502:physiology*; D011995:Recombination, Genetic; D012190:Retroviridae / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements