Huntingdon’s disease gene therapy shows promise
MedWire News: Mesenchymal stem cells expressing small hairpin (sh)RNA capable of inhibiting expression of the huntingtin protein show promise for future treatment of Huntingdon's disease (HD), suggest study results.
"For the first time, we have been able to successfully deliver inhibitory RNA sequences from stem cells directly into neurons, significantly decreasing the synthesis of the abnormal huntingtin protein," said study author Jan Nolta (University of California Davis Health System, Sacramento, USA) in a press statement.
"Our team has made a breakthrough that gives families affected by this disease hope that genetic therapy may one day become a reality," she said.
There are currently no approved or effective therapies for prevention or against progression of HD. However, RNA interference (i) technology has successfully reduced mutant huntingtin protein and progression of HD in mouse models.
In order for this technology to be reliably transferred to humans, a strong and sustainable method of delivering RNAi to affected neurons is needed, say Nolta and team.
The team demonstrated the ability of mesenchymal stem cells to carry and transfer RNAi to target cells using stem cells carrying RNAi against green fluorescent protein. The stem cells were able to reduce the amount of GFP in a GFP expressing cell line.
The researchers genetically engineered mesenchymal stem cells from the bone marrow of unaffected donors to carry RNAi capable of inhibiting the mutated huntingtin protein seen in patients with HD. They then demonstrated that these stem cells were capable of reducing the amount of mutant huntingtin expressed by modified glioblastoma and neuroblastoma cell lines using Western blot and densitometry.
"A number of genetic diseases that are currently incurable and often untreatable could benefit greatly should mesenchymal stem cells, or another cell type, be able to deliver efficacious amounts of RNAi directly to affected cells over a prolonged period of time," write the authors in Molecular and Cellular Neuroscience.
"The potential benefits of cellular therapies and RNAi therapies combined may be sufficient to delay or even halt disease progression, which could dramatically improve quality of life for patients suffering from degenerative diseases like HD," they add.
"Not only is finding new treatments for HD a worthwhile pursuit on its own, but the lessons we are learning are applicable to developing new therapies for other genetic disorders that involve excessive protein development and the need to reduce it," commented Nolta.
"We have high hopes that these techniques may also be utilized in the fight against some forms of amyotrophic lateral sclerosis (Lou Gehrig's disease), as well as Parkinson's and other conditions."
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By Helen Albert