Is there a possibility of using stem cells from a relative's umbilical cord to use for spinal cord cell cure treatment? I saved my niece's umbilical cord last year hoping there would be a day to use for a cure for my spinal cord injury or if my niece ever has a use for it.
-A curious adult from Arizona
November 10, 2006
One day this sort of thing might be possible. In fact, there is even a claim that this very strategy has worked in South Korea.
A woman who had been a paraplegic for 19 years received matched umbilical cord stem cells. According to the scientists who did the work, within six weeks she could walk with a walker.
But after a second operation her condition worsened. And now she complains of severe pain.
South Korean scientists have repeated the experiment on other patients. Some of these patients complained of complications. Others had mild improvements.
Another procedure has been done on people using stem cells from a patient's nose. Why nose stem cells?
Well, nerve stem cells are incredibly rare. The only abundant ones that are easy to get are found in the nose (they're used for our sense of smell).
A doctor in Portugal has treated over 30 different spinal cord patients with their own nose stem cells. (Actually these cells are called olfactory ensheathing and stem-like progenitor cells but we'll keep calling them nose stem cells.)
These patients have made definite improvements and so the results are encouraging. As long as it is safe and the effects last that is. Like the work done in South Korea, this work is at a very early stage.
Too early really. It was almost certainly not a good idea to start human experiments quite yet.
Before starting on people, these scientists should have done more work in animals first. And this is what other scientists are doing.
Why you might ask should they be doing animal studies first? Don't we want to help people who are suffering right now?
Well yes but we want to make sure the therapy can work. And we want to make sure it is safe. Animal studies can help us figure this out.
For example, it might be that stem cells work at first and then stop working (like gene therapy). Or stem cells might become like a cancer.
Cancers are cells that can grow and so are stem cells. Scientists want to make sure these stem cells stay where they are supposed to and don't end up like a cancer.
All of these things would be better to find out in animals first. And the early results from animal experiments are encouraging.
Let's start with the most controversial experiments -- those using embryonic stem cells. Embryonic stem cells are said to hold the most promise because they can become any other kind of cell.
So why isn't everyone using embryonic stem cells? Because their use has major ethical and medical issues.
Right now an embryo needs to be destroyed to get a hold of its stem cells. Anyone who considers the embryo to be a life is going to be troubled by this.
In the near future, scientists will probably be able to get these cells without destroying the embryo. Despite all the recent hoopla, though, we aren't there yet. (Click here to learn more about this.)
And even if we overcome this ethical problem, we still have the problem of rejection. Embryonic stem cells may not match the paralyzed person's cells. If this is the case, then the body will reject them.
In the future, rejection may not be a big issue for embryonic stem cells either. People will make embryos from themselves and harvest their own embryonic stem cells.
Of course, they'll have to either destroy the embryo or make a clone of themselves. So the ethical dilemma will likely be here for years to come!*
So real therapies with embryonic stem cells are still a ways off. But like I said, the early work in animals is very encouraging.
For example, a group at UC Irvine has managed to use human embryonic stem cells to partially cure rats with spinal cord injuries. And after a year the rats are still OK.
But it only works on recently injured rats. A rat with a 7 day old spinal injury was helped. One with a 10 month old spinal injury was not.
In other words, the work they're doing might not help people who injured their spine years ago. And this line of research still suffers from ethical and rejection problems.
Besides embryonic stem cells, scientists are also doing animal studies with adult stem cells. Some of these experiments are showing promise as well.
We've already talked about a couple of these stem cells that were used in the human studies. But wait a minute. Aren't umbilical cord stem cells the same thing as embryonic stem cells? No.
Umbilical cord stem cells are adult stem cells. You can see why scientists don't like calling these cells adult. They prefer the term somatic. More of a mouthful but you don't have to deal with fetal stem cells being adult!
Anyway, adult stem cells don't have any real ethical problems. Rejection problems are less significant too.
The umbilical cord stem cells can come from a relative decreasing the chance for rejection. And other adult stem cells (like the nose ones) can come from the patients themselves. No rejection risk there!
Early animal work suggests that adult stem cells might be an alternative to embryonic stem cells. People are finding nerve-like cells in umbilical cord stem cells. They are also finding that when these cells are put into the spinal cord environment, they can turn into nerve stem cells.
Studies using both nose and umbilical cord stem cells have shown that the cells went to the injury and turned into some nerve cells. A number of studies showed some improvement and some did not. The early safety data looks promising as well.
So lots of work is being done on treating spinal cord injury with stem cells. The most promising results are those with embryonic stem cells in animals. But some of the early work with adult stem cells is looking promising as well.
The stem cells aren't turning into cancers. They are staying at the site of the injury and turning into nerve cells. And some scientists are starting to do proper safety studies in people as well.
This is all very encouraging. Perhaps sooner rather than later stem cells will be used to help heal injured spinal cords.
*Personalized stem cells may become less controversial if all children start out with their own embryonic stem cells -- click here to learn more about how this might happen.
By Dr. Barry Starr, Stanford University