Genomic analysis of Sleeping Beauty transposon integration in human somatic cells

PLoS One. 2014 Nov 12;9(11):e112712. doi: 10.1371/journal.pone.0112712. eCollection 2014.

Abstract

The Sleeping Beauty (SB) transposon is a non-viral integrating vector system with proven efficacy for gene transfer and functional genomics. However, integration efficiency is negatively affected by the length of the transposon. To optimize the SB transposon machinery, the inverted repeats and the transposase gene underwent several modifications, resulting in the generation of the hyperactive SB100X transposase and of the high-capacity "sandwich" (SA) transposon. In this study, we report a side-by-side comparison of the SA and the widely used T2 arrangement of transposon vectors carrying increasing DNA cargoes, up to 18 kb. Clonal analysis of SA integrants in human epithelial cells and in immortalized keratinocytes demonstrates stability and integrity of the transposon independently from the cargo size and copy number-dependent expression of the cargo cassette. A genome-wide analysis of unambiguously mapped SA integrations in keratinocytes showed an almost random distribution, with an overrepresentation in repetitive elements (satellite, LINE and small RNAs) compared to a library representing insertions of the first-generation transposon vector and to gammaretroviral and lentiviral libraries. The SA transposon/SB100X integrating system therefore shows important features as a system for delivering large gene constructs for gene therapy applications.

MeSH terms

  • Animals
  • Cell Line
  • DNA Transposable Elements / genetics*
  • Fibroblasts / metabolism
  • Gene Transfer Techniques
  • Genetic Vectors
  • HeLa Cells
  • Humans
  • Keratinocytes / metabolism
  • Mice
  • Transposases / genetics*
  • Transposases / metabolism

Substances

  • DNA Transposable Elements
  • Transposases
  • sleeping beauty transposase, human

Grant support

Funding was received for this study from Italian Ministry of University and Research-FIRB 2008 (AR), DEBRA international (AR) and the European Research Council (GT-SKIN) (FM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.