Bush’s bioethicist on stem cell alternatives

To his fans, he's the "Defender of Dignity." To his detractors, he's the "Irrationalist in Chief."

In the four years since Dr. Leon Kass was named chairman of the President's Council on Bioethics, his observations have riled those who favor going further on the frontiers of human embryonic stem cell research and therapeutic cloning — and have rallied those who worry about the frontier's ethical and moral pitfalls.

Three months ago, Kass and his fellow council members issued a white paper outlining research avenues that might yield the benefits of embryonic stem cells while staying within federal funding guidelines on the use of human embryos. During a mid-July interview with MSNBC.com, Kass discussed the white paper — as well as dramatic developments that have come to light since the report was issued.

Kass emphasized that the four alternative approaches outlined in the white paper were not meant as "recommendations" for future legislation — but in fact they dovetailed with the congressional debate over the president's policies on stem cell research.

In the interview, Kass focused on the science of stem cells rather than the politics, and he was particularly anxious to talk about recent research into cell fusion and reprogramming. That subject serves as the starting point for this edited transcript:

On cell reprogramming:

Kass: I would like to talk with you about reprogramming, because I think that’s where the gold is buried. Since the council’s white paper has been issued, we’ve been made aware of three major scientific reports that indicate to me at least that the reprogramming alternative is, A., hotly under investigation, and B., moving much more rapidly than we had any reason to suspect even two months ago when the report was issued.

Let’s remind ourselves, the goal is to get cells that are the functional equivalent of embryonic stem cells, but to do so in a morally unproblematic and uncontroversial way. And ideally this could be done also without the need for human eggs. So the most morally attractive proposal would be to try to reprogram or dedifferentiate adult cells back to the pristine condition of multipotency or pluripotency, the condition that the cells have when they are stem cells.

Since every cell in the body is genetically the same as any other, what distinguishes the liver cell from a brain cell from a heart muscle cell is not the presence or absence of certain genes, but which genes are in fact turned on and functioning, and which ones are silent. And since the process of development and differentiation going forward starts with a cell that could become anything, but specializes to become liver, or brain, or heart — presumably if you could locate the signal that produced that specialization, and run the process in reverse, you could start from liver, or heart or brain or muscle or skin, run the process in reverse and get back to the "stemcellness" of the beginning.

Lots of scientists have talked about this, but in the last two months, there have been very exciting reports from Australia, from Harvard and out of the Center for Reproductive Genetics in Chicago, that suggest that this morally unproblematic path might also be scientifically efficacious.

Let me begin with what is to me the most exciting one: Dr. Yuri Verlinsky in Chicago has at a scientific meeting in May in London announced that he has succeeded in producing a dozen new stem cell lines by reprogramming somatic cells using a technique of cell fusion. … He’s in fact applied for a patent. … Basically what he does is he starts with an existing embryonic stem cell line. He used his own, but this could be done with the presidentially approved lines, of which there are now 22 available from the National Institutes of Health and out in use in research.

You start with an existing embryonic stem cell line. Verlinsky removes its nucleus, and then he fuses the nucleus-free stem cell with a body cell — let’s say a skin cell. And the result is a cell which is genetically like the skin cell of the donor, but retains the stem cell properties of the original. So what’s wonderful about this is that you have all of the advantages of so-called cloning for research, without the need for eggs, and without producing a cloned embryo in the process.

You could in principle get stem cells from diabetics, stem cells from people with Parkinson’s disease that carry these markers, just by fusing cells taken from adults who have these diseases.

If this pans out, and that’s a very important “if,” this research would be eligible for federal funding in humans right now … providing the work was done with the eligible stem cell lines. There’s absolutely no reason why people couldn’t use those lines in these fusion experiments.

So that, I think, has been the most dramatic claim.

MORE FROM CLONING AND STEM CELLS

Cloning and stem cells Section Front

New cancer-killing method found in stem cells New way to make stem cells discovered New embryonic stem cell rules limit funding Scientist: First cloned camel born in Dubai A few states buck stem cell trend with bans Stem cell payoff could take decades not days Opinion: Finally, a coherent stem cell policy Patients glad to have final say on embryos’ fates Researchers find safer way to make stem cells Fetal stem cells trigger tumors in ill boy Cloning and stem cells Section Front   Add Cloning and stem cells headlines to your news reader: