Preventing gene silencing with human replicators.
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.
Fu
Haiqing
H
Laboratory of Molecular Pharmacology, NCI, Bethesda, Maryland 20892, USA.
Wang
Lixin
L
Lin
Chii-Mei
CM
Singhania
Sumegha
S
Bouhassira
Eric E
EE
Aladjem
Mirit I
MI
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
D002843:Chromatin