Daily pill to beat genetic diseases
This is an incredible and huge step in medicine, we're getting closer. In our life times we will see a revolution in molecular medicine and will harness the genome rendering diseases like cancer a thing of the past. When I was in college a girlfriend of mine had a son who had Duchenne muscular dystrophy and I urged her not to give up hope as novel approaches were just beginning to take form, science fiction has become reality.
Daily pill to beat genetic diseases
April 23, 2007
Mark Henderson, Science Editor
A pill that can correct a wide range of faulty genes which cause crippling illnesses should be available within three years, promising a revolution in the treatment of thousands of conditions.
The drug, known as PTC124, has already had encouraging results in patients with Duchenne muscular dystrophy and cystic fibrosis. The final phase of clinical trials is to begin this year, and it could be licensed as early as 2009.
As well as offering hope of a first effective treatment for two conditions that are at present incurable, the drug has excited scientists because research suggests it should also work against more than 1,800 other genetic illnesses.
PTC124 targets a particular type of mutation that can cause very different symptoms according to the gene that is disrupted. This makes it potentially useful against a range of inherited disorders.
The same drug could be given to patients with Duchenne muscular dystrophy, the most serious form of the muscle-wasting condition, cystic fibrosis, which mainly affects the lungs, and haemophilia, in which the blood does not clot. It can be taken orally, and safety trials have not revealed any major side effects.
“There are literally thousands of genetic diseases that could benefit from this approach,” Lee Sweeney, of the University of Pennsylvania, who is leading the research, said. “What’s unique about this drug is it doesn’t just target one mutation that causes disease, but a whole class of mutations.”
In most genetic conditions, between 5-15 per cent of cases are caused by a defect called a “nonsense mutation”. Genes are instruction manuals for cells to make proteins, but nonsense mutations in effect introduce a command halfway through that stops production. The kind of protein disrupted determines the nature of the disease.
In Duchenne muscular dystrophy, for example, the protein necessary for normal muscle development is not made, and the fatal wasting disease is the result. In haemophilia, it is the gene for the clotting agents factor VIII or factor IX that is disrupted.
PTC124 works by binding to a part of the cell called the ribosome, which translates genetic code into protein, and allows it to ignore nonsense mutations. The gene can be read straight through and a normal protein is produced.
The beauty of the drug is that it should be useful with any disease caused by a nonsense mutation, no matter what its outward effects. The error is not corrected, but ignored. Patients would have to take the pill throughout their lives.
PTC124, which is made by PTC Therapeutics, has been staggeringly successful in animal models. A study published today in Nature shows that in mice with a nonsense mutation that causes Duchenne muscular dystrophy, the drug starts dystrophin production and restores their muscles to health.
The drug has passed safety trials in humans, and the results of phase-two trials on cystic fibrosis and Duchenne muscular dystrophy will be published shortly.
About 13 per cent of patients with Duchenne muscular dystrophy have a nonsense mutation and should respond to the drug. It would not be suitable for treating different mutations in the dystrophin gene, or diseases not caused by nonsense mutations.
Other diseases that can be caused by nonsense mutations include beta thalassaemia, a blood disorder, and Hurler syndrome, in which children’s mental and physical development stops and most patients die by the age of 10.
Another great story!
Nanotechnology used to treat spinal cord injuries
Last Updated: Monday, April 23, 2007 | 3:38 PM ET
Paralyzed lab mice with spinal cord injuries have regained the ability to walk after being injected with a nanomaterial, a scientific conference heard Monday.
The research raises hope that nanotechnology might be used in treating degenerative illnesses such as Parkinson's disease and Alzheimer's disease, according to Samuel Stupp, a Northwestern University professor who presented his findings at a session hosted by the Project on Emerging Nanotechnologies in Washington.
"By injecting molecules that were designed to self-assemble into nanostructures in the spinal tissue, we have been able to rescue and regrow rapidly damaged neurons," he said in a statement.
"The nanofibres ... are the key to not only preventing the formation of harmful scar tissue which inhibits spinal cord healing, but to stimulating the body into regenerating lost or damaged cells," said Stupp, director of the Institute for Bionanotechnology in Medicine at Northwestern.
Nanotechnology is the applied science of manipulating and controlling matter at a scale below 100 nanometres, or in the range of 1/100,000th the width of a human hair.
Stupp said he and his co-workers have designed molecules with the capacity to self-assemble into nanofibres once injected into the body with a syringe.
He said the work could eventually be used to help cure degenerative illnesses and help repair or regenerate damaged cells.
Early testing urged
The Project on Emerging Nanotechnologies also issued a report Monday suggesting the future of nanotechnology would be in providing better medical treatments and providing clean water and energy.
The report, NanoFrontiers: Visions of the Future of Nanotechnology, said the industry would need to focus on acquiring better tools to view nanoscales, manage the information and create the materials.
It also suggested early testing to ensure nanomaterials are safe for public use.
"Many future surprises might be avoided by carefully testing nanomaterials up front in order to gauge their toxicities and to predict how easily they could spread in water, air and soil," the report said.
"We, as a society, could then choose to work with the new materials that appear most useful and benign and to avoid the riskier ones."
A UN report released in February at the Global Ministerial Environment Forum called for more research in nanotechnology to identify environmental, health and socio-economic hazards.