According to a recent article by UMass Medical School, promising new research from scientists at UMass supports the potential of gene therapy as a treatment for amyotrophic lateral sclerosis. The study, called ‘Safe and effective superoxide dismutase 1 silencing using artificial microRNA in macaques’, was published in Science Translational Medicine and can be found here.
About Amyotrophic Lateral Sclerosis (ALS)
ALS, also known as Lou Gehrig’s disease, is a neurological disorder that affects voluntary muscle control. This can cause problems with movements such as walking, talking, and chewing, and, because the condition is progressive, the symptoms get worse over time. ALS is caused by damage to neurones, which relay messages between the brain and muscles. Without this connection, muscles can begin to weaken and waste away. Approximately 5 to 10% of ALS cases are familial (inherited), while the other ~90% are sporadic. According to the NIH, several genes have been linked to familial ALS, and an estimated 12-20% of cases are connected to mutations in the gene SOD1.
The researchers tested an experimental gene therapy that uses microRNA to target SOD1. They used the therapy to ‘turn off’ the gene and stop it from producing proteins that may play a role in the disease. One challenge when creating the drug was the high number of SOD1 gene mutations linked to ALS – over 180. To get around this, the scientists found commonalities in DNA between many of these mutations, which they could use to create a therapy that was able to target many SOD1 mutations, rather than only one.
What the Researchers Found
Previous research that silenced SOD1 in mouse models of ALS had shown encouraging results, including delayed disease onset and a longer survival period, and results from the more recent study were similarly encouraging. The gene therapy was found to reduce SOD1 protein production by up to 93% in motor neurones. Furthermore, the drug showed limited side-effects, with no liver toxicity or detected unintended silencing of other genes. The next step, the scientists say, is to carry out clinical trials in patients.