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Today’s News & Views If you've kept track, you probably already know that there have been a slew of proposed ways to extract or create embryonic stem cells. What jumps out is that such morally unacceptable ideas keep coming down the chute with nary a nod at the proven track record of adult stem cells. As Dr. David Prentice has written "At least a dozen studies now show adult stem cells from bone marrow, umbilical cord blood, and placenta have the flexibility of embryonic stem cells, but without the scientific or ethical problems. And adult stem cells have already claimed success in treating at least 65 different human diseases." Meanwhile, there has been no success in humans using embryonic stem cells. News about a different technique leaked out yesterday. The formal announcement will be made Friday in the journal "Science." I do not pretend to be a scientist or a researcher, but I hope the following layman's overview will satisfactorily explain what's been reported about the work of Kevin Eggan, Chad A. Cowan, and other Harvard biologists. These researchers reportedly created embryonic stem cells without using human ova or creating new embryos. They fused ordinary skin cells with laboratory-grown human embryonic stem cells. Something (yet to be determined) in the stem cells "reprogrammed" the adult cell?s genes so thoroughly that the skin cell itself was turned into an embryonic stem cell. As a press release from Harvard put it, the embryonic cells "reset the genetic clock of the adult cells, turning them back to their embryonic form." "Since the new stem cells in this technique are essentially rejuvenated versions of a person's own skin cells, the DNA in those new stem cells matches the DNA of the person who provided the skin cells," writes the Washington Post's Rick Weiss. In theory, there would be little risk of rejection because the newly created stem cells would "constitute an exact genetic match." To repeat, wherever/however the embryonic stem cells came from, any remedial properties remain strictly hypothetical. As Weiss himself writes, "Researchers caution, however, that like many other nascent therapies that initially seemed promising, stem cells may never live up to their promise." There are problems yet to be worked out. For instance, while the newly- minted hybrid has all the characteristics of a new embryonic stem cell, it possess the DNA of both the initial embryonic stem cell and the DNA of the person who donated the skin cell. To proceed any further, the extra DNA from the original stem cell would need to be removed. At least one story had this tantalizing tidbit: "In the future, scientists hope to begin the process with an adult cell and convert it into an embryonic cell before fusing it." So where does this fit into the larger discussion? The general idea proffered by proponents is that stem cells from embryos are like all-purpose repair kits. However, if they are, so to speak, off the rack (from so-called "spare embryos" from fertility clinics, or from an aborted baby), there are any number of problems--beginning with the recipient's immune system which will attack foreign tissue. Thus, the push for "tailor made" stem cells via cloning. The human clone would be scavenged for stem cells. Most newspaper accounts emphasized that the Harvard approach seems to avoid this "controversial" practice. One other (among many) interesting considerations. Many critics complain that the cell lines which were in existence prior to August 2001-- the only ones that can be used if federal dollars are to underwrite the research -- are "old" and/or genetically flawed. But if the Harvard research pans out, the newly-created stem cells would possess the perfectly normal genetic makeup of the adult skin cell that was fused with the original embryonic stem cell. To come full circle, all this is highly speculative. And, more to the point, the fascination with embryonic stem cells takes our eye off the ball -- the extraordinary success to date using adult stem cells. You can reach me, Dave Andrusko, at dandrusko@nrlc.org. |
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