Researchers make stem cell discovery by studying tissue stress and repair
GWEN IFILL: Today's news of a breakthrough in stem cell research captured the attention of scientists around the world.
For years, researchers have been investigating how to get adult stem cells to behave more like embryonic ones, which would allow them to be developed into almost any organ or tissue. The findings announced today involve a simple treatment, immersing adult mouse cells in a mild acid bath. As seen here, mouse embryos were grown with beating heart cells derived from this process.
Dr. Charles Vacanti was one of the lead researchers from the team at Brigham and Women's Hospital. And he joins me now.
Dr. Vacanti, this is kind of amazing. Are you explaining -- are you telling us you're making stem cells, instead of finding them?
DR. CHARLES VACANTI, Brigham & Women's Hospital: That is correct. And we believe we're doing exactly what's being done in the body when you normally have an injury.
GWEN IFILL: So how did you come about this?
CHARLES VACANTI: It's been a long process.
I started working with this with my brother Martin about 15 years ago, first looking for a better cell to use in tissue engineering. And in 2001, we described a stem cell that we thought we had found, and several years later, we started to wonder, rather than finding the cell, were we making the cell with the harsh environment of the isolation process?
GWEN IFILL: And that's the acid bath I was just referring to?
CHARLES VACANTI: Yes.
And, actually, we tested seven different stimuli to see which stresses would cause mature cells to naturally revert back to their embryonic stem cell state.
GWEN IFILL: I have to -- I noticed, Doctor, you're an, anesthesiologist and your brother is?
CHARLES VACANTI: A pathologist.
GWEN IFILL: A pathologist.
Neither of you are stem cell experts. How did you stumble across this discovery?
CHARLES VACANTI: Well, we started doing this in the early days of stem cell reports. And, in the 1990s, there were very few stem cell reports. And it seemed logical.
We had had a lot of experience with tissue engineering, but it seemed logical that in order to do this effectively, we would need to find a better cell than currently used mature cells.
GWEN IFILL: By the way, when you say you have some experience with tissue engineering, you're the guy who grew the ear on the mouse back in the day. I think it was the late '90s?
CHARLES VACANTI: Actually, 1995. I am guilty of that one.
GWEN IFILL: I still remember those pictures. It was creepy then, creepy now.
But let's stick back to what you have discovered now. Are you saying that the research premise all these years for all these experts who were trying to get to the bottom of how to create stem cells, the research premise was wrong?
CHARLES VACANTI: I'm saying that when I read a lot of the stem cell papers, when you describe their isolation process, the harsh conditions, the conclusion was that people were killing adult cells and only the very hardy stem cells were surviving.
And I think that they were looking at it from the wrong perspective. So we started to wonder, if, rather than in natural, normal injury and repair, is it the stem cells that reside in the tissue doing the repair, or the harsh environment causing mature cells to change back to stem cells, which are doing the repair?
GWEN IFILL: Interesting.
CHARLES VACANTI: And it seems like a simple difference, but I think it's important.
GWEN IFILL: Well, one the differences, it seems to me, is that you know the debate around stem cell research has always been around embryonic stem cell research, because you had to destroy embryos in order to get access to that. And that has crossed all kinds of barriers for people. This, if it pans out, removes that possibility?
CHARLES VACANTI: That was the intention.
So it is my belief that we can now create autologous, so specific for any individual, their own embryonic stem cells for use to generate new tissue without ever having to create an embryo or ever having to destroy an embryo.
GWEN IFILL: So give me a practical therapeutic application for this. And obviously we're not growing ears on the backs of mice anymore.
GWEN IFILL: So say this is possible for human use. What is the benefit?
CHARLES VACANTI: So, my belief is you could use it for many, many, many organs, and I will give you an example.
If you look at any vital organs, your heart, your lungs, your liver, your kidneys, you only need about 20 percent function in any of those organs to survive. So when people go into kidney failure or lung failure, it's because they are down to less than 20 percent function. They may be down to 10 percent.
So rather than building an entire new kidney or entire new lung, which is a noble cause, and I think will be achieved some day, why not start with delivering cells to those injured tissues, those diseased tissues, and see if you can boost the function back up over 25 percent? And now you can live a normal, healthy life.
So, I think the first applications will be not growing new tissue, but boosting existing tissue function.
GWEN IFILL: So, if...
CHARLES VACANTI: An example -- sorry.
GWEN IFILL: Go ahead.
I was going to ask you for an example. If you have a heart that's not pumping blood the way it ought to be, and it's working at some percentage less than it could be, you could build that heart back up?
CHARLES VACANTI: Just build it back up. Use serial delivery of these cells that will then turn into heart muscle and you may take your heart function from a very low ejection fraction to one that's compatible with life.
GWEN IFILL: It's fascinating.
So, assuming that this is tested now in mice, is it being tested in other species? And then how long -- it takes a while -- before we begin to see an application in humans?
CHARLES VACANTI: So, we have already tested it in several other species. And we have even begun work with human skin cells.
And what we found in primates and humans and sheep and pigs, we found the process is very similar. So we have isolated cells. We believe we have reverted them back to stem -- to embryonic stem cells, and we started to test these. We have not done it to the same degree that we demonstrated in this report, because this is an extremely sophisticated, complicated, and expensive study to do.
So we are slowly doing all the necessary markers and gene studies, but our early studies are very suggestive that we have now repeated it in older animals, in primates, and in humans. But we have yet to determine if, indeed, they are as potent as the cells that we created in the mice.
GWEN IFILL: Well, we will be watching to see what happens next. It's truly fascinating science.
Dr. Charles Vacanti of Brigham and Women's Hospital in Boston, thank you.
CHARLES VACANTI: Thank you so much.