A group of Japanese scientists has used gene therapy to deliver three insulin transcription factors, MafA, PDX-1, and NeuroD, to the livers of diabetic mice. As a result, the mice experienced an increase in insulin gene expression and insulin production, raising the possibility that this could eventually be used to treat diabetes. The research appears as the "Paper of the Week" in the April 15 issue of the Journal of Biological Chemistry, an American Society for Biochemistry and Molecular Biology journal.

Dr. Hideaki Kaneto, of the Osaka University Graduate School of Medicine, and his colleagues over-expressed the insulin transcription factors MafA, PDX-1, and NeuroD in the liver of mice. The researchers did this by inserting the transcription factors into adenovirus and then injecting the adenovirus into the cervical vein of the mice. Each transcription factor was detected only in the liver and not in other tissues after infection with the adenovirus. The result was that the mice had a marked increase in insulin gene expression and therefore insulin production.

The researchers also discovered that overexpression of these three transcription factors in the livers of diabetic mice dramatically ameliorated glucose tolerance in these animals.

Adenovirus vector cannot be used to deliver genes into humans.

Thus, it will be necessary to modify the vector or to develop some other technique to deliver the transcription factor genes into humans.

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