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GEN News Highlights : Sep 27, 2007

Safer and More Efficient Gene Delivery Method Suggested

Preliminary work done by a UW scientist published in Applied Biosafety looks at transposons to enable gene therapy.

A University of Wisconsin-Madison (UW) scientist says that she has discovered a gene delivery system that is safer than using viruses and more efficient than plasmids. Molecular biologist and associate biological safety officer Margy Lambert describes the gene-delivery potential of transposons, stretches of DNA capable of jumping from one DNA molecule to another.

When used in gene delivery, viruses can be infectious and some types occasionally land in a target genome near an oncogene and raise the risk of cancer, according to Lambert. Plasmids don't carry that risk, but they are not nearly as efficient at reproducing in cells.

Techniques for targeting transposon vectors to regions of the genome devoid of cancer genes are being refined, Lambert says. Meanwhile, an advantage over simple plasmids is that jumping gene technology is more effective at achieving stable expression of genes introduced into animal cells, she adds.

To harness jumping genes, researchers use an enzyme to ferry a desired DNA sequence from one DNA molecule to another inside a cell. The enzyme can then be turned off to stop genes from jumping.

Lambert acknowledged that there are both technical and safety issues to be worked out in the development of transposon vectors before they could be tried in human therapy. But the use of such new vectors “offers a great opportunity to maximize the advantages and minimize the drawbacks of existing delivery systems.”

The research is published in the September issue of the Applied Biosafety.