Stem Cell Research Panel

August 23, 2000

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Robin: How different is it to work with stem cells from embryos and from adults?

Evan Snyder: I think that the difference between embryonic stem cells, fetal stem cells, and adult stem cells from all organs - but particularly from the brain and spinal cord - is still an area of active investigation, and the fact is we don't entirely know whether they are absolutely identical or not. So, from a research point of view, it is very important that our ability to work with all of them, often in parallel experiments, not be constrained. At one level one might think that by definition, a stem cell from one developmental period should be identical to a stem cell from another developmental period (if we are, in fact, going to give it that name), but we really don't know that. And the truth may actually be that each disease in each organ may require its own particular type of strategy, involving its own particular type of stem cell. And, in fact, since most neurologic disease is complex, one may even need to use a combination of different kinds of stem cells in different stages of development and different stages of commitments, as co-grafts.

BioMan Asks: Are stem cells the one true hope that spinal cord injury victims have at the moment? And how soon can those people see results that will actually help them from the research?

John McDonald: You know, I think we all believe that there is no one hope for any disease and that in the end it will require multiple strategies. Currently, there are multiple clinical trials at the Phase Three level in spinal cord injury that do not involve transplantation. Those, too, raise considerable hope. One clear problem after spinal cord injury is the body's inability to adequately replace cells lost consequent to injury. With the recent discovery that there are adult stem cells found in the spinal cord that are capable of generating new replacement cells, this raises additional hope. A lot of transplantation studies that are being done today are ways of understanding how to harness the potential of the indogenous stem cells. And in the end, the hope will be that we will simply be able to stimulate those indogenous cells - to adequately replace the cells and circuits lost after injury. So, although stem cell transplantation raises considerable recent hope, the final treatments will involve multiple different interventions, just as Dr. Snyder has pointed out.

Evan Snyder: I completely agree with everything that John said in terms of saying that multi-faceted approaches are going to be required. And what one of the big questions is that comes up is now that we recognize that stem cells exist all throughout life, what is the best way to harness this biology? And John very nicely outlined multiple approaches. One involves using exogenous stem cells - the transplantation paradigm - and those cells obviously can come from a developing organism like an embryo or a fetus, or it can come from an adult. Or one can try to stimulate endogenous stem cells. What we believe happens in many situations is that the body does try to repair itself, and that the mediator of this self-repair may be the stem cell.

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