No human embryos created or destroyed: Embryonic Stem Cells Created from Skin Cell.

The latest chapter in the stem cell saga comes from researchers Chad A. Cowan, Kevin Eggan, Douglas Melton, and Jocelyn Atienza at the Harvard Stem Cell Institute. They have created embryonic stem cells without using human ova or creating new embryos by fusing an adult skin cell with an existing line of embryonic stem cells. If proven to work, the technique would appear to circumvent lethally harvesting stem cells from human embryos.

However, while the research has received a great deal of attention, there are several important considerations.

First, there are other more promising sources, including, in particular, stem cells from umbilical cord blood. (See below.) These "adult" stem cells (meaning non-embryonic) already have proven therapeutic track records.

Second, the same team at Harvard suggested in a conference call with reporters that if they can figure out what coaxes adult stem cells to revert to embryonic stem cells, they might avert altogether the use of existing embryonic stem cell lines.

And, third, before such hybrid cells could be transplanted, the leftover DNA from the original "starter" embryonic stem cell needs to be removed. There is research in that area current being undertaken in a number of labs.

As reported in the journal Science, the Harvard Stem Cell Institute researchers fused ordinary skin cells with already existing embryonic stem cell colonies. 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 Harvard News Service 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," wrote the Washington Post's Rick Weiss. "In theory at least, that means that any tissues grown from those newly minted stem cells could be transplanted into the person to treat a disease without much risk that they would be rejected, because they would constitute an exact genetic match."