Functional nucleotide sequences capable of promoting non-viral genetic transfer

Abstract

6 Conclusions: Currently, significant advances in the development of non-viral vectors are being made by means of recent technological innovations, including nanotechnology (Vijayanathan et al. 2002). Employment of functional genetic elements, such as EBNA1/oriP and the SB transposon, may further improve their efficacy, compensating for the shortcomings of non-viral systems. EBV-based plasmid vectors are transported into and maintained in the nucleus as well as replicated as episomes, overcoming the problems of the low transfection rate and the transience of transgene expression. The SB transposon enables chromosomal integration of a transgene in transfected cells, potentially enabling its permanent expression, although random integration into the host genome may cause aberrant expression and/or silencing of cellular genes that locate close to the integration site. Both the EBV-based plasmid vector and SB have been shown to work not only in vitro but also in vivo. Plasmid vector sequences should be focused on as an important component of non-viral gene delivery systems, while their combination with other devises, such as polypeptides containing a nuclear localization signal (reviewed in Hebert 2003), may also be useful in developing promising strategies.