RNA as a source of transposase for Sleeping Beauty-mediated gene insertion and expression in somatic cells and tissues.

Sleeping Beauty (SB) is a DNA transposon capable of mediating gene insertion and long-term expression in vertebrate cells when co-delivered with a source of transposase. In all previous reports of SB-mediated gene insertion in somatic cells, the transposase component has been provided by expression of a co-delivered DNA molecule that has the potential for integration into the host cell genome. Integration and continued expression of a gene encoding SB transposase could be problematic if it led to transposon re-mobilization and reintegration. We addressed this potential problem by supplying the transposase-encoding molecule in the form of mRNA. We show that transposase-encoding mRNA can effectively mediate transposition in vitro in HT1080 cells and in vivo in mouse liver following co-delivery with a recoverable transposon or with a luciferase transposon. We conclude that in vitro-transcribed mRNA can be used as an effective source of transposase for SB-mediated transposition in mammalian cells and tissues.