16 November 2007

Oregon's triumph

Oregon Health & Science University (OHSU) this week announced an important breakthrough in embryonic stem-cell technology.

It has long been a goal of stem-cell research to be able to create embryonic stem cells with the DNA of a specific individual, so that therapies involving the implantation of stem cells could be done without risk of rejection by the body's immune system. There is an established method for doing this, called "somatic cell nuclear transfer" (SCNT). The way SCNT works is that a cell -- any cell -- is taken from the adult organism's body (skin cells are often used, since they are easily accessible), and its nucleus, containing the individual's DNA, is extracted. An egg cell from a female is also procured, and its nucleus carefully removed, leaving the rest of the egg cell intact. Then the nucleus from the adult organism is implanted in the egg cell and fused with it by means of either a jolt of electricity or certain chemicals. If the procedure is carried out correctly, the result is a viable egg cell with the adult organism's DNA. The egg cell then divides as it normally would, eventually developing into a microscopic ball of embryonic stem cells -- all containing the DNA of the individual from which the implanted nucleus was taken -- which can then be extracted and used for whatever therapies that individual needs.

While SCNT has been carried out in some mammal species, it has never been successfully done in primates, because the egg cells of primates are especially vulnerable to damage by the standard procedures used to remove the original nucleus and insert its replacement. Since humans are primates, this was a serious obstacle to the development of stem-cell therapies for human patients.

This week, OHSU's scientists announced that they had succeeded in performing SCNT using cells from rhesus monkeys -- a primate species -- and had created a viable line of embryonic stem cells containing the DNA of a specific individual monkey.

The next step, of course, is to try the same process with human cells, and OHSU's achievement has made scientists confident that the same methods will work for our own species. It's a huge step toward the day when the almost magical potential of embryonic stem cells will be routinely exploited to the full to cure countless terrible diseases in human beings. And it was done right here in the Portland area.

Official OHSU press release

New York Times report

Los Angeles Times report

Washington Post report