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Parkinson's May Be Treatable With Therapeutic Cloning
In a step closer to developing a treatment for Parkinson's in humans using 
therapeutic cloning, scientists in the US and Japan have for the first time 
used cells from a mouse to treat Parkinson's in the same mouse.
The study is published in the advanced online issue of the journal Nature 
Medicine and is the work of investigators at the Memorial Sloan-Kettering 
Cancer Center (MSKCC) in New York, and the Riken Institute in Kobe, Japan.
Hailed as the first study of its kind, the investigators showed that 
therapeutic cloning, or somatic cell nuclear transfer (SNCT), using cells 
from a mouse to treat the same mouse can be successful. Although so far only 
demonstrated in animals, if the success is replicated in humans, it will 
open the door to treatments that reduce transplant rejection and improve 
recovery in a range of other diseases and medical conditions.
Therapeutic cloning or SNCT involves removing the nucleus from an egg and 
replacing it with the nucleus of the subject. Thus the egg develops using 
the DNA of the donor of the nucleus and not the donor of the egg. The egg 
develops into a blastocyst cell that yields embryonic stem cells with the 
potential to become a range of cell types that can be used therapeutically.
Since the cells develop with the DNA of the donor of the nucleus, when 
implanted into the donor's body, they will not be attacked by the donor's 
immune system.
In this new study, senior author Dr Lorenz Studer, who is Head of the Stem 
Cell and Tumor Biology Laboratory within the Sloan-Kettering Institute at 
MSKCC, and lead author Dr Viviane Tabar, Neurosurgeon and stem cell 
scientist at MSKCC, used skin cells from the tails of 24 mice with Parkinson's 
to create 187 cell lines, from which they derived dopamine neurons that were 
customized to each individual's DNA. Dopamine neurons are brain cells that 
are missing or not working effectively in Parkinson's disease.
They then grafted the customized cells into mice with the same DNA as the 
cells. And another control group of mice received cells with DNA that did 
not match their own. The mice that received dopamine neurons that matched 
their own DNA showed neurological improvement and lack of immunological 
response whereas those that received mismatched cells did not.
The study has been welcomed by experts as bringing medicine a step closer 
toward an effective treatment for Parkinson's, a chronic and progressive 
brain disease for which there is currently no cure although there are drugs 
that slow and relieve the symptoms. However, some have also remarked that 
there is still a long way to go before it can be said that such a treatment 
will be successful in humans.
Speaking to BBC News, Robin Lovell-Badge, a professor in stem cell research 
at the National Institute of Medical Research in London, UK, said that this 
study demonstrated the potential for therapeutic cloning in the treatment of 
Parkinson's, but while the successfully treated mice made a significant 
recovery, they were only studied for 11 weeks, which is not long enough to 
tell if the treatment persists.
The Washington Post reported a comment from assistant professor Michael 
Jakowec, a neurologist at the George and MaryLou Boone Parkinson's Disease 
and Movement Disorders Research Center at the University of Southern 
California Keck School of Medicine in Los Angeles, who said that moving the 
science from mice to humans is a "gigantic" step.
Jakowec told the Post that:
"You see a lot of failures in studies that try to translate success from 
rodents to humans."
He suggested it might be premature to move to humans next, perhaps the 
method shoud be demonstrated in primates first, but there is no doubt that 
it opens "a new avenue of therapeutic strategy, which may ultimately benefit 
patients down the road," said Jakowec.
"Therapeutic cloning in individual parkinsonian mice."
Viviane Tabar, Mark Tomishima, Georgia Panagiotakos, Sayaka Wakayama, 
Jayanthi Menon, Bill Chan, Eiji Mizutani, George Al-Shamy, Hiroshi Ohta, 
Teruhiko Wakayama & Lorenz Studer.
Nature Medicine, Published online: 23 March 2008.

Rayilyn Brown
Director AZNPF
Arizona Chapter National Parkinson Foundation
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