Treatment of TT1 mice with transposon-based gene therapy

ABSTRACT: DNA transposon-based gene delivery vectors represent a promising new branch of randomly integrating vector development for gene therapy. For the side-by-side evaluation of the piggyBac and Sleeping Beauty systems - the only DNA transposons currently employed in clinical trials - during therapeutic intervention, we treated the mouse model of Tyrosinemia type I. with liver-targeted gene delivery using both transposon vectors. For genome-wide mapping of transposon insertion sites we developed a new Next Generation Sequencing procedure called Streptavidin-Based Enrichment Sequencing, which allowed us to identify approximately 1 million integration sites for both systems. We revealed that a high proportion of piggyBac integrations are clustered in hot regions and found that they are frequently recurring at the same genomic positions among treated animals, indicating that the genome-wide distribution of Sleeping Beauty-generated integrations is closer to random. We also revealed that the piggyBac transposase protein exhibits prolonged activity, which predicts the risk of oncogenesis by generating chromosomal double-strand breaks. Safety concerns associated with prolonged transpositional activity draw attention to the importance of squeezing the active state of the transposase enzymes into a narrower time window.

ORGANISM(S): Mus musculus

PROVIDER: GSE212895 | GEO | 2023/03/09

REPOSITORIES: GEO