title: Preventing gene silencing with human replicators.
abstract: Transcriptional silencing, one of the major impediments to gene therapy in humans, is often accompanied by replication during late S-phase. We report that transcriptional silencing and late replication were prevented by DNA sequences that can initiate DNA replication (replicators). When replicators were included in silencing-prone transgenes, they did not undergo transcriptional silencing, replicated early and maintained histone acetylation patterns characteristic of euchromatin. A mutant replicator, which could not initiate replication, could not prevent gene silencing and replicated late when included in identical transgenes and inserted at identical locations. These observations suggest that replicators introduce epigenetic chromatin changes that facilitate initiation of DNA replication and affect gene silencing. Inclusion of functional replicators in gene therapy vectors may provide a tool for stabilizing gene expression patterns.
authors.affiliation: Laboratory of Molecular Pharmacology, NCI, Bethesda, Maryland 20892, USA.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Fu
authors.forename: Lixin
authors.initials: L
authors.lastname: Wang
authors.forename: Chii-Mei
authors.initials: CM
authors.lastname: Lin
authors.forename: Sumegha
authors.initials: S
authors.lastname: Singhania
authors.forename: Eric E
authors.initials: EE
authors.lastname: Bouhassira
authors.forename: Mirit I
authors.initials: MI
authors.lastname: Aladjem
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism; D004261:DNA Replication; D044127:Epigenesis, Genetic; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D051379:Mice; D008957:Models, Genetic; D010957:Plasmids / Q000378:metabolism; D014158:Transcription, Genetic; D019076:Transgenes
chemical_list: D002843:Chromatin