In the study, scheduled to be published online in the Proceedings of the National Academy of Sciences the week of Jan. 2, the researchers used gene therapy to introduce a healthy copy of the gene dystrophin into mice with a condition that mimics muscular dystrophy. The dystrophin gene is mutated and as a result produces a defective protein in the roughly 20,000 people in the United States with the most common form of the disease.
Using gene therapy to treat muscular dystrophy isn't a new idea. Thomas Rando, MD, PhD, associate professor of neurology and neurological sciences, said that researchers have tried several different techniques with variable success. One hurdle is getting genes into muscle cells all over the body. Another is convincing those cells to permanently produce the therapeutic protein made by those genes.
The gene therapy technique Rando and postdoctoral fellow Carmen Bertoni, PhD, used was developed by Michele Calos, PhD, associate professor of genetics. One of the main advantages of this method is that it could potentially provide a long-term fix for a variety of genetic diseases, including muscular dystrophy.
In muscular dystrophy, the muscle cells break down and are slowly replaced by fat. Eventually people with the disease are confined to a wheelchair and usually die in their 20s. There is currently no effective treatment for the disease, which explains why gene therapy remains a hope despite the significant hurdles.
Rando said the PNAS paper highlights an additional requirement for any gene therapy to be successful: the introduced gene must produce healthy dystrophin protein in large quantities in order to repair the entire muscle cell. Previous muscular dystrophy gene therapy studies
Source:Stanford University Medical Center