CBN.com - With President Bush preparing to make a decision about the federal government's position on embryonic stem cell research, Melissa Charbonneau of CBN News sat down to talk with Dr. John Chute, a hematologist and oncologist conducting adult stem cell research in Bethesda, Maryland for a National Institutes of Health-U.S. Navy study. This probing interview looks at the extensive history and promising future of stem cell research.
This is Part 1 of a two-part interview with Dr. Chute.
Melissa Charbonneau: In the last several years, what advances have we seen in embryonic stem cell research?
Dr. John Chute: The major advance was at the University of Wisconsin, where they first demonstrated they could cultivate very early stem cells from embryonic tissue. And that was in the last five years. Subsequently, there's been demonstration, at least the suggestion that embryonic stem cells can be induced in a culture to differentiate into other types of tissue.
Charbonneau: What's the significance of that discovery?
Chute: There's a whole host of diseases, neurologic diseases like Alzheimer's, Parkinson’s, where the defining aspect of the disease is the degeneration of normal tissue. So, there's the hope or the anticipation in the community at large, and even in the medical community, that stem cells could be induced to make different tissue, so that you could transplant those tissues into someone who has the disease and replace tissue that had degenerated like in patient with Alzheimer's or Parkinson’s.
The major hope and anticipation is in the community at large and in the media. I think that far outweighs what scientific and medical community has defined yet as to what the potential of those cells are.
Charbonneau: What's the main source of embryonic stem cells?
Chute: The primary source is any fetal tissue, however that's obtained medically. It's tissue that's obtained medically through the various, many different manners people obtain fetal tissue at medical institutions.
Charbonneau: Talk about your research into adult stem cells.
Chute: To say the term adult stem cells indicates a wide variety of cells. But when people in the medical community are talking about adult stem cells, generally they're speaking about hematopoetic stem cells, blood origin stem cells from adult tissue. And there are three sources of those, bone marrow, cord blood, and peripheral blood, drawn from the arm like a sample of blood from a blood test, blood circulating in your body that you can pull out of vein very easily.
There is also evidence, very early evidence, that there are stem cells in other tissues, like in the brain, there is a neuronal stem cell, a brain stem cell. But those are exceptionally rare, and as you can imagine, very difficult to obtain. The liver has evidence that there are stem cells through the liver, such that other liver cells generate over the life of an individual from these types of stem cells.
It's probable that almost every organ in the body has a stem cell population within it, but they are exceptionally rare. And the only real organs we know we can obtain stem cells for use medically is from blood organs, such as bone marrow, cord blood and peripheral blood.
Charbonneau: Adult blood stem cells?
Chute: Adult blood stem cells. The primary original use was for people with leukemia and certain types of cancer that we, again 25 years ago, the oncology community demonstrated you could cure people with various types of leukemias with what's called a stem cell transplant.
Charbonneau: So this is really nothing new?
Chute: Well, adult blood stem cells have been under the study of scientists and medical researchers for almost 30 years. And there's much more evidence as to the biology of those cells and what they can or cannot do, as opposed to other sources of stem cells, such as embryonic tissue, which as we just talked about is an area of medical research much more in its infancy.
Charbonneau: Is it easier to get a good supply of embryonic stem cells than adult stem cells?
Chute: No, actually the reality is, in terms of searching for adult stem cells, it's very easy to get stem cells out of the bone marrow. It's quite easy to get it out of a sample of cord blood every time a mom delivers a baby, the doctor can collect 50-100 ml's of blood, and there are stem cells within that. It's also very easy to get it out of peripheral blood. These are all standard in current medical practice we know how to do.
Charbonneau: What have you found recently about adult stem cells that suggests they have more potential in finding cures?
Chute: The major advance interestingly in the last five years with adult stem cells, is these cells appear — the key word is appear, these are very preliminary studies in animal models — these cells appear to have what we call "plasticity," such that they under certain conditions may be able to differentiate into other tissues at a low level.
The translation is, these cells — as opposed to just being committed to being blood cells, which is what we thought they were committed to do — is that if you transplant them into another tissue, say you take a bone marrow stem cell and you transplant it into injured liver, there is scientific suggestion that those cells under the right signals inside a person's body may be able to differentiate and contribute to the development of liver tissue.
Charbonneau: So before, for example, you thought blood cells could only be used to create blood cells? Now you think adult blood stem cells can be turned into liver cells?
Chute: The major scientific excitement about adult blood stem cells is they may have the potential — and each month there seems to be a new article on this — that they can differentiate into other types of tissues. And the tissues thus far that have been demonstrated so far are liver, brain tissue — which is quite exciting — muscle, and even recently a very exciting paper demonstration that bone marrow stem cells could differentiate into cardiac muscle… You can imagine the excitement about that for people who work with cardiac patients. So, there's great excitement about it, and interestingly, all in the last five years. So that little niche of information is also blossoming at the same time that the excitement about embryonic stem cells has also been building.
Charbonneau: What's your message to people just now tuning in to the stem cell debate?
Chute: I think the most important message is adult blood stem cells have been there for 30 years. We've used them safely, and we've treated thousands of diseases with these cells. We know they're generally safe to transplant into other people. And there's now evidence scientifically that these cells have the potential that was not known before, and potential to be used to help people with degenerative diseases.
I think it's a good thing that this whole discussion on both sides has brought more focus to adult stem cells and the capacity these cells have. In the past it really hasn't been the focus of the public's attention, so I think it's a good thing. Ironically it's been a great time to do adult stem cell research because we're now seeing attention brought to an area of medical therapeutics that has great excitement to it. And there are many diseases that are candidates to be treated with adult stem cells.
Please read Part 2 of this series: A Closer Look at Adult Stem Cell Research, Part 2
