U.S. researchers said on Sunday they had used cloned cells to treat a Parkinson-like disease in mice and said it provided a good experimental basis for testing whether so-called therapeutic cloning will work.
While they did not clone each individual mouse, the cells they used were from cloned embryos and relieved the symptoms of artificially induced Parkinson’s, they reported in this week’s issue of the journal Nature Biotechnology.
Cloning is highly controversial but many scientists believe therapeutic cloning can revolutionize medicine. The idea is for a patient to provide a single cell that could be manipulated and grown into new tissue or even organs.
Theoretically, it could cure juvenile diabetes, severe injuries and diseases such as Parkinson’s, which is caused when the body mistakenly destroys healthy brain cells.
Lorenz Studer of Memorial Sloan-Kettering Cancer Center in New York and colleagues were working with embryonic stem cells — the body’s master cells, valued because they have the potential to become any kind of cell in the body.
The cells were directed to become several different types of brain cell — including the dopamine-producing cells that are destroyed in Parkinson’s.
The researchers created symptoms of Parkinson’s in six mice using chemicals to damage their brains, then transplanted the dopamine-producing cells into their brains.
The symptoms of the mice got better, the researchers reported. Usually mice with this brain damage walk in constant circles.
When killed and examined, the mice had healthy colonies of the transplanted cells in their brains.
“There has been great interest in developing renewable cell sources for the generation of dopamine neurons in the experimental treatment of Parkinson disease,” they wrote.
Their experiment may be a basis for further study — perhaps by cloning each individual mouse to make a tiny embryo that could then provide tailor-made stem cells for the brain treatment.
The eventual goal, the researchers said, would be to try this in humans. But President Bush, who strongly opposes cloning and research involving human embryos, has greatly restricted federal funding for such experiments.
Bills are pending in Congress that would ban them outright.