Perpetuating a Needless Stem-Cell War
Obama's decision is bad ethics, bad science, and bad politics.
1:00 PM, Mar 9, 2009 • By RYAN T. ANDERSON
I described the November 2007 breakthrough in the pages of THE WEEKLY STANDARD as marking "The End of the Stem-Cell Wars"--though a better title might have been "What Should Be the End of the Stem-Cell Wars." Scientists had succeeded in transforming an ordinary skin cell into a stem cell with the properties of an embryonic stem cell by using viral vectors to reprogram the cell to a pluripotent state. But researchers were concerned that these viruses, which integrated themselves into the stem cell, might pose an obstacle to therapeutic use. Last September, a team of researchers discovered a way to use the viruses to reprogram the cells, but without being integrated. And last week, researchers published a paper showing that they can reprogram an adult cell into a pluripotent stem cell without using viruses at all. Instead, they simply insert a sequence of DNA (called "piggyBac") carrying four genes that reprogram the cell. Andras Nagy, who led the research behind this technique, explained that "after they do their job they can be removed seamlessly, with no trace left behind. The ability for seamless removal opens up a huge possibility."
Harvard's George Daley described the study as "very significant," adding that he thought it was "a major step forward in realizing the value of these cells for medical research." Robert Lanza, of the prominent Advanced Cell Technology, said it was "very exciting work. . . . we're only a hair's breadth away from the biggest prize in regenerative medicine--a way to create patient-specific cells that are safe enough to use clinically."
This, of course, points to the scientific advantages that induced pluripotent stem cells bring.
First, they're cheaper and easier to work with than cells produced by killing human embryos. Not surprisingly, hundreds of labs have made the switch from embryonic stem cells to induced pluripotent ones.
Second, and very importantly, induced pluripotent stem cells are patient specific. As anyone familiar with organ transplants knows, immune rejection is a major hurdle to any form of regenerative medicine. Induced pluripotent stem cells clear this hurdle because they can be created using the patient's own skin cells; thus they will have his exact DNA sequence and will not be prone to immune rejection. For embryonic stem cells to do the equivalent, they would have to be created from an embryo produced by human cloning. Clearly, then, Bush's critics were being disingenuous when they claimed to want only the IVF "spares"--embryos that "were going to die anyway." While those might have been the first cells needed for basic research, any therapeutic uses would require patient-specific cells, attainable only by cloning. That would open up ethical debates over human cloning and killing--and debates about the ethics and safety of encouraging (or paying) women to subject themselves to hormonal stimulation to produce eggs for use in the cloning process. Using induced pluripotent stem cells avoids all of these problems.
It is, therefore, critically important to note what Obama did not say this morning. He promised that he would make sure that "our government never opens the door to the use of cloning for human reproduction." He went on to add that "it is dangerous, profoundly wrong, and has no place in our society, or any society." This is certainly correct. But in pledging only to prevent reproductive cloning, Obama intentionally left the door open for research cloning. The cloning procedure involved, of course, is exactly the same in reproductive and research cloning; the only difference is that in research cloning the developing human is killed before being allowed to be born. Given what we know about the necessity of cloning for the medicinal use of embryonic stem cells, Obama's implicit support for research cloning and killing is unconscionable.
All of that said, while human cloning has yet to be performed, let alone perfected, non-embryo-destructive techniques to produce patient-specific induced pluripotent stem cells are available now. Yet another advantage.