Bogus Gold

In the course of noting that President Obama's reversal of the federal embryonic stem cell funding ban may have been undone when he signed the omnibus spending bill two days later, Ed Morrissey makes the following observation about embryonic stem cell therapies:

The promise of stem-cell research lies in the ability of pluripotential cells to generate new human tissue to cure diseases. ...

We can do that now, of course, but we call it something else: transplants. We can take numerous kinds of human tissue and transplant them from one human to another — kidneys, livers, hearts, lungs, pancreases, and now even faces. We face two obstacles to making this a massively available technology, though; inventory of replacement materials and the need to suppress the immune system to allow the transplants to succeed.

...only adult stem-cell therapies address the second problem. The body’s immune system can detect foreign tissue and attacks it. Without immunosuppressive therapy, most transplants (excepting, I believe, corneal transplants) would fail and the patient will die.

Ed goes on to detail his personal experience in helping his wife cope with her own immunosuppresive therapy. It's a good illustration of a major issue confronting those who intend to derive therapies.

But it's not entirely accurate to say it's an issue embryonic stem cell researchers have not been addressing. In fact, the reason the issue of cloning is often raised in conjunction with embryonic stem cell research is precisely this. Cloning - often called therapeutic cloning, or more clinically somatic cell nuclear transfer - is intended to resolve the issue of immune system rejection of embryonic stem cells.

The reasoning behind this technique is simple: if the embryonic stem cells are an exact genetic match to the patient, there should be no immune system rejection of the therapeutically introduced stem cells, or of the tissue which develops from them. To accomplish this genetic match, a researcher begins with a donated human egg cell. The nucleus of the egg cell is removed and replaced with material from the nucleus of a somatic cell (e.g. a skin cell) from the intended stem cell recipient. The cell is induced to begin dividing, and allowed to develop for several days before the resulting stem cells are extracted. During the extraction process the developing embryo is destroyed. By this method a researcher is able to obtain embryonic stem cells genetically matching an intended patient. Immune system rejection resolved.

Of course there may be a slight problem with this. Many of the most vociferous advocates of embryonic stem cell research insist that the cloning of human embryos is entirely beyond the pale, and something they would never countenance. Many go to great pains to call out their opposition to cloning at the same time they call for the advancement of embryonic stem cell research. I suspect such advocates have little understanding of the conflict such a position creates.

However, I also don't believe their desire for embryonic stem cell derived therapies is going to be held up by such a contradiction. What I would expect is something like this, which is the position of the American Association of Medical Colleges:

Somatic Cell Nuclear Transfer (SCNT) or therapeutic cloning involves removing the nucleus of an unfertilized egg cell, replacing it with the material from the nucleus of a "somatic cell" (a skin, heart, or nerve cell, for example), and stimulating this cell to begin dividing. Once the cell begins dividing, stem cells can be extracted 5-6 days later and used for research. The AAMC supports on-going research into SCNT and has endorsed legislation that would allow such research to flourish.

Reproductive cloning, on the other hand, is intended to create human beings by cloning human embryos. The AAMC and the National Academy of Sciences recommend a ban on all forms of this type of cloning.

When is a clone not a clone? The answer, according to the AAMC, is when you don't intend to use it for human reproduction. The process for creating the cloned human for other purposes remains the same. This is, after all, the same process used to create such celebrity lab experiments as Dolly the Sheep. The only concrete distinction is whether or not the resulting embryo is destroyed early in development or not.

And so, prepare for the political version of the "clone wars." It's closer than you think.

UPDATE:

Well that didn't take long. From a New York Times editorial today:

Let us hope that the N.I.H. broadens the range of stem cells that can be studied.

Scientists believe that one way to obtain the matched cells needed to study diseases is to use a cell from an adult afflicted with that disease to create a genetically matched embryo and extract its stem cells. This approach — known as somatic cell nuclear transfer — is difficult, and no one has yet done it. ...

When the N.I.H. sets the rules for federally financed research, the main criterion should be whether a proposal has high scientific merit.

Note the careful avoidance of the hot-button word "cloning." That's probably how most of the press will frame this issue - avoid clear terminology in favor of obscure technical terms. That way most of the public won't even realize how this issue relates to human cloning.

But once this genie is out of the bottle, it will be very difficult to control it. High scientific merit is easy to link to the ability to clone humans for research purposes. It's only the ethics of it that constrain the issue, and our science media seem to have lost theirs.