Posted on 10/23/2006 10:24:34 AM PDT by truthandlife
Injecting human embryonic stem cells into the brains of Parkinson's disease patients may cause tumors to form, U.S. researchers reported on Sunday.
Steven Goldman and colleagues at the University of Rochester Medical Center in New York said human stem cells injected into rat brains turned into cells that looked like early tumors.
Writing in the journal Nature Medicine, the researchers said the transplants clearly helped the rats, but some of the cells started growing in a way that could eventually lead to a tumor.
Various types of cell transplants are being tried to treat Parkinson's disease, caused when dopamine-releasing cells die in the brain.
This key neurotransmitter, or message-carrying chemical, is involved in movement and Parkinson's patients suffer muscle dysfunction that can often lead to paralysis. Drugs can slow the process for a while but there is no cure.
The idea behind brain cell transplants is to replace the dead cells. Stem cells are considered particularly promising as they can be directed to form the precise desired tissue and do not trigger an immune response.
Goldman's team used human embryonic stem cells. Taken from days-old embryos, these cells can form any kind of cell in the body. This batch had been cultured in substances aimed at making them become brain cells.
Previous groups have tried to coax stem cells into becoming dopamine-releasing cells.
Goldman's team apparently succeeded and transplanted them into the rats with an equivalent of Parkinson's damage. The animals did get better.
But the grafted cells started to show areas that no longer consisted of dopamine-releasing neurons, but of dividing cells that had the potential to give rise to tumors.
The researchers killed the animals before they could know for sure, and said any experiments in humans would have to be done very cautiously.
Scientists have long feared that human embryonic stem cells could turn into tumors, because of their pliability.
Opponents of embryonic stem cell research cite such threats. Many opponents, including President George W. Bush and some members of Congress, believe it is immoral to destroy human embryos to obtain their stem cells.
The results in the above article? Profoundly unsurprising. They've known that FOR YEARS.
Now, I'm against using ES cells. But there is still the possibility that this research can teach about how the cell life cycle of adult cells, pattern of differentiation, etc.
There's enough progress being made in medicine without the need for embryonic stem cells. This is yet another reason to tread very carefully here.
Full disclosure: Whether ESC's promote tumors or not, and the science thus far seems to suggest just that, killing humna embryo's for utilitarian purposes crosses a line I'm not willing to travel even if it extended my life.
Even without tumor formation, the effect of injecting the cells seems to be roughly equivalent to taking a dopamine precursor drug. This is hardly the road to a "cure".
Rush needs this info right now since he is talking about Michael J Fox.
Anyone around here have Rush's insider attention?
Embryonic stem cell research causes death everywhere.
Michael J. Fox is wrong: Jim Talent supports stem cell research
See #8
Which begs the question, why? Why not keep the animals alive and observe the final result rather than make claims that the ESC's "clearly helped the rats". What kind of science is this?
Well that depends on ones perspective. I clearly oppose ESC research that kills human embryos.
>>>Steven Goldman and colleagues at the University of Rochester Medical Center in New York said human stem cells injected into rat brains turned into cells that looked like early tumors. >>>
That's because the body is fighting against a FOREIGN BODY.
But I bet this won't play in a World Series Commercial break.
Yes and yes. Bank your babies cord blood.
A pity if true.
Not necessarily, because your own stem cells would carry the same genetic flaw responsible for any gene-based disorder. In the end, there won't be any meaningful difference between "adult" and "embryonic" stem cells. By the time all the obstacles to effective treatment are solved, any stem cell will have the potential to produce a new baby.
Adult stem cells have also been found to cause cancer. http://www.newscientist.com/channel/sex/mg18624965.200
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