Stem cells in the news
A big week for stem cells
Stem cells, stem cells, stem cells. We hear about these things all the time it seems. Here in California, we ponied up 3 billion dollars to look into them.
Well, judging by this week's news, it may well be worth the money. There were two big stories about stem cells this week.
The first was using cloned embryos to create personalized stem cells for patients. The second was using stem cells from umbilical cord blood to actually treat a disease. Wow, it was a big week!
Before discussing these stories in detail, let's make sure we understand what a stem cell is and why they have such potential. If you have a pretty good handle on stem cells already, you can skip this part and start in on the two stories.
Most cells in our body are stuck doing what they do. A liver cell will always be a liver cell; a muscle cell will always be a muscle cell.
And they can't make new copies of themselves. In other words, when they die, they can't replace themselves.
Stem cells are different. Stem cells can keep making more and more of themselves creating an almost endless supply. They can also change into other cells like muscle, nerve, blood or almost anything else.
Where do you find these wonderful cells? The stem cells that can really become any other cell are found only in embryos. Embryos need to be able to make every different kind of cell from a single cell. So these early cells need to be able to become anything.
What makes stem cells controversial is that to get these cells, an embryo must be destroyed. Which is one of the reasons people are looking hard at another type of cell, the adult stem cell.
When a blood cell dies off, where does its replacement come from? Blood stem cells in our bone marrow. Many of our other tissues also have their own supply of adult stem cells.
These stem cells usually can't easily become any other kind of cell. Blood stem cells pretty much turn into different kinds of blood cells in the body. Researchers are working hard to coax them into different kinds of cells but stem cells from embryos are still more versatile.
Where can stem cells be used to treat disease? There are lots of problems that are caused by the loss of some important tissue. Some examples include diabetes, Parkinson's, or spinal cord injuries.
Scientists are trying to use stem cells to recreate the lost cells in these diseases. For example, in diabetes, new pancreatic cells could replace the lost ones. Now instead of treating diabetes with insulin, scientists are hoping to cure it with stem cells.
Your own personal embryonic stem cells
Say it ain't so, Joe! Or should I say Hwang Woo Suk? Unfortunately, the results we talk about in this part of the article have been shown to be false. Investigations are currently ongoing to see if the data was deliberately falsified.
The ideas still stand and one day scientists will do what Hwang Woo Suk has claimed he has done. It will be just a matter of time thank goodness science is self correcting!
This is big news. All the scientists I talked to about this went gaga over it. Scientists in South Korea led by Woo Suk Hwang and Shin Yong Moon have made embryonic stem cells with DNA that exactly matches the patient's. No one thought this could be done as quickly as this.
This is a big deal because one of the big problems with stem cells is the same problem with the transfer of any tissue from one person to anotherrejection. If the stem cell doesn't match up, then the body may reject it.
So, an obvious answer is to use our own stem cells. But the most versatile kind are the ones from embryos and they are long gone. So is there any way to get some of these?
One way is by cloning. And that is exactly what these South Korean scientists did. And no, this isn't like Dolly the sheep they didn't grow the clone all the way.
They only grew it big enough to collect some stem cells. These stem cells can now be grown in the lab and someday maybe put back into a patient.
The way they did this was to start out with a donated egg. They took out the whole nucleus with all of its DNA. They did this by making a small tear in the cell and squeezing out the nucleus.
They then put a skin cell inside the egg and gave it an electric jolt to fuse the two cells. They grew the cloned embryo for six days and then put it onto feeder cells. This is also an important step.
Many stem cell lines that are around now can't be used in people because they were grown with animal feeder cells. Fears of some new, unknown animal virus prevent the use of these lines in people. These new stem cell lines, though, could be used in people.
OK, so they got rid of the animal feeder cells. Haven't they done all of the rest already? Well, they've done it with a lot of animals, but not much in people. In fact, this same South Korean group is the only one to have cloned a human embryo before, from just one healthy woman.
What they've done now is made the whole system more routine. Instead of 242 eggs, the process took only around 20. They were able to do it with men and women between the ages of 2 and 56. And they used DNA from people with diabetes, spinal cord injuries and genetic immune diseases.
Eventually they'd like to, for example, put the stem cells from a spinal cord patient back into that patient so he can walk again. While this is a big step forward, the therapies are still years away. But they won't be possible without this huge first step.
A use for stem cells right now
Stem cells hold great promise but are they being used anywhere in medicine today? Embryonic stem cells aren't, but adult stem cells are.
Most people have heard of bone marrow transplants. Bone marrow transplants are really blood stem cell transplants. So, if a disease is treated with a bone marrow transplant, it is getting treated with stem cells.
One disease that is treated with bone marrow transplants is Krabbe's disease. In Krabbe's disease, the nervous system doesn't develop properly. People with Krabbe's disease often don't live past the age of 2.
Treatment is only really possible if the disease is caught early. What doctors do is destroy the affected person's immune system with chemotherapy. They then replace the destroyed bone marrow with new bone marrow.
The new bone marrow contains stem cells that can slow down any new damage. The issue with the bone marrow transplant is you need a matched donor and you need one fast. Krabbe's disease progresses pretty rapidly so you want to start the treatment as soon as possible.
This is where umbilical cord blood comes in. Umbilical cord blood contains stem cells too. Unlike bone marrow, banked umbilical cord blood is readily available. So, if doctors could use it instead of bone marrow, then they could begin treatment almost immediately.
And this is what this story is about. The researchers looked at 11 babies who weren't yet showing symptoms and 14 other babies at various stages in the disease.
The results were very encouraging for the babies treated before symptoms appeared. The progression of the disease slowed down significantly. The study isn't far enough along to figure out how much the disease has been slowed but so far the results are good.
Babies already showing symptoms, however, weren't helped as much. It may be that by the time symptoms can be seen, there has been too much damage. The treatment doesn't heal damage that has already happened, it slows down any new damage.
One lesson from this study is that it is really important to treat babies with Krabbe's before symptoms appear. This might suggest that newborn screening could be really important for this disease.
So as you can see, this was a really big week for stem cells. At this rate, maybe we'll have treatments sooner rather than later. If only Chris Reeves were around to see this