Thursday, November 15, 2007

Primates Cloned

Scientists have successfully cloned primates to produce embryos that they harvested for stem cells, as announced by the journal Nature yesterday:

Not only is this the first time such cells have been produced in any animal other than a mouse, but the method, the researchers say, should also work in humans. In 2004, South Korean researchers reported making stem cells from cloned human embryos, but the claim turned out fraudulent.

“We hope the technology will be useful for other labs that are working on human eggs and human cells,” the lead researcher of the group, Shoukhrat Mitalipov at Oregon Health and Science University in Beaverton, said in a telephone interview. “I am quite sure it will work in humans.”

The monkey stem cells were genetically identical to an adult monkey, Semos, whose cells were cloned. They are a sort of universal cell that can, in theory, develop into any tissue or organ.

The scientists began by removing skin cells from a 9-year-old adult male rhesus macaque and inserted them, along with all their genes, into monkey eggs whose genetic material had been removed.

The egg, in a part of the cloning process that remains mysterious, reprogrammed the genes from the skin cells, bringing them back to the state they were in when embryo development begins.

The reprogrammed genes took over developing the eggs. A result was monkey embryos that were genetically identical — clones — of the adult male monkey. A few days later, the investigators extracted stem cells from the embryo clones, destroying the embryos in the process.

In other words the point was to produce a genetically idential primate to the one whose skin sample was taken, but rather to produce a viable embryo from which stem cells could be taken, and on this scientists scored a success. Similar methods in the past have failed repeatedly, leading some to believe that primates couldn't be cloned. But barriers to the technique have been removed, and while the process still only produced one viable stem cell line from 304 eggs, there appears to be no reason at this time why the effort cannot be duplicated by other researchers.

As the article states, this has stoked fears that human cloning is just around the corner. Dr. Art Caplan, Director for the Center of Bioethics at Pennyslvania University, says we shouldn't be unduly worried about this possibility:

The Oregon announcement is very welcome news if you suffer from diabetes, nerve damage, paralysis or heart failure. Cloning human embryos using the Oregon technique should jump-start embryonic stem cell research using your own cells to get the process going.

Some will argue that none of this research should be permitted in humans. Won't cloning human embryos make it too tempting to use them for reproduction as well as research? And isn't it murder, some will say, to clone human embryos to then destroy them to harvest stem cells from them. Neither argument carries sufficient weight for politicians and governments to ban cloning for research.

While it is true that the creation of stem cells means destroying a cloned embryo, a cloned embryo in a lab dish has no ability to develop into a person. It is at best a possible person -not an actual one. Moreover, we already know that nearly all cloned embryos are so miswired that very few are capable of becoming a healthy adult organism at all, making cloned human embryos far more ethical to use for embryonic stem cell research than human embryos created solely for research purposes.

It has taken 10 years but the prospect of human cloning has now inched very close to becoming a reality. We don't need to panic in response to this prospect. We need to proceed with great caution. While we may not want to use cloning as a way to make people we should create laws and policies that permit the use of cloning to help create the cells that can heal and repair the people who are already here.

Overall, I agree with Caplan. Given the potential benefits this procedure could have for people suffering all kinds of genetic and degenerative diseases, it would be immoral to turn away from such research out of the interest of preserving embryos, especially when many of the embryos that would be used for this research could come from the estimated 400,000 embryos that are estimated to be frozen in the United States but for which there is little hope of being used. And fears of reproductive human cloning are exaggerated. Scientists don't know whether a cloned embryo could produce a fully developed and healthy human being, and the wouldn't conduct experiments to find out give the wildly unethical nature of such experiments.

At the same time, I do think it's time for legislation regarding both therapeutic and reproductive cloning. The only thing approaching a federal standard is the ban on federal funds being used on stem cell research, but measures banning reproductive cloning have failed. Most states haven't addressed the issue either, and those that have take differing views; California voted to support stem-cell research, but in Louisiana frozen embryos more than four days old are considered to be as fully human as borne children.

Unfortunately because of the delay in implementing sensible legislation and this new discovery, the political debate surrounding such legislation is likely to be heated, confused and hyperbolic. It would have been better to take the matter seriously while we could still anticipate such developments, and not merely react to them. But now is better than never.

No comments: