Adult stem cells taken from humans suffering from Duchenne muscular dystrophy can be genetically modified and used to treat the disease in a mouse model, researchers report today in Cell Stem Cell.

Duchenne muscular dystrophy is a progressive condition caused by a mutation on the X chromosome that leads to a lack of dystrophin protein in muscle. The mutation is usually caused by a deletion or mutation in the gene, leading to a shift in the reading frame of mRNA translation. In past studies, injecting Duchenne mice with normal muscle cells has temporarily staved off disease symptoms, but that technique does not work reliably and can cause immune rejection. So researchers have proposed delivering muscle progenitor cells instead.

Yvan Torrente of the University of Milan, Italy, and colleagues took human blood- and muscle-derived stem cells from Duchenne patients. They used antisense oligonucleotides delivered by lentiviral vectors to mask the incorrect mRNA splicing sites, thus returning translation to its normal reading frame. They then intramuscularly injected the corrected cells into the sick mice. Within three weeks, the transplanted cells gave rise to muscle fibers and spurred production of the dystrophin protein. The authors caution, however, that using viral vectors may cause tumor formation, and that details of the technique such as its efficiency remain to be worked out.

Both the antisense techniques and muscle cell transplantation have been tried before in Duchenne, note Kay Davis of Oxford University and Miranda Grounds of the University of Western Australia in an accompanying review article. But the combination of the two makes this a proof of principle study that shows that "steady progress is being made toward the goal of stem cell-mediated restoration of dystrophin expression," they write.