title: Genomic discovery of potent chromatin insulators for human gene therapy.
abstract: Insertional mutagenesis and genotoxicity, which usually manifest as hematopoietic malignancy, represent major barriers to realizing the promise of gene therapy. Although insulator sequences that block transcriptional enhancers could mitigate or eliminate these risks, so far no human insulators with high functional potency have been identified. Here we describe a genomic approach for the identification of compact sequence elements that function as insulators. These elements are highly occupied by the insulator protein CTCF, are DNase I hypersensitive and represent only a small minority of the CTCF recognition sequences in the human genome. We show that the elements identified acted as potent enhancer blockers and substantially decreased the risk of tumor formation in a cancer-prone animal model. The elements are small, can be efficiently accommodated by viral vectors and have no detrimental effects on viral titers. The insulators we describe here are expected to increase the safety of gene therapy for genetic diseases.
authors.affiliation: Division of Medical Genetics, University of Washington, Seattle, Washington, USA.
authors.forename: Mingdong
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, Washington, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Maurano
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, Washington, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: 1] Division of Medical Genetics, University of Washington, Seattle, Washington, USA. [2] Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Heyuan
authors.initials: H
authors.lastname: Qi
authors.affiliation: 1] Division of Medical Genetics, University of Washington, Seattle, Washington, USA. [2] Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Chao-Zhong
authors.initials: CZ
authors.lastname: Song
authors.affiliation: Division of Medical Genetics, University of Washington, Seattle, Washington, USA.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Navas
authors.affiliation: 1] Division of Medical Genetics, University of Washington, Seattle, Washington, USA. [2] Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Emery
authors.affiliation: 1] Department of Genome Sciences, University of Washington, Seattle, Washington, USA. [2] Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Stamatoyannopoulos
authors.affiliation: 1] Division of Medical Genetics, University of Washington, Seattle, Washington, USA. [2] Department of Genome Sciences, University of Washington, Seattle, Washington, USA.
authors.forename: George
authors.initials: G
authors.lastname: Stamatoyannopoulos
mesh_terms: D001665:Binding Sites / Q000235:genetics; D000076246:CCCTC-Binding Factor; D002843:Chromatin / Q000235:genetics*; D019295:Computational Biology; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D005822:Genetic Vectors; D015894:Genome, Human; D023281:Genomics; D006801:Humans; D038101:Insulator Elements / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D002843:Chromatin; D012097:Repressor Proteins