Cow clone research produces kidney-like organs
Ethics questions aside, experts see hope for human transplants
Scientists in Massachusetts have used cells derived from cloned cow embryos to grow kidney-like organs that function and are not rejected when implanted into adult cows, marking the first use of cloning technology to grow organs for transplantation.
The research, described Tuesday by the scientist who led the work, has not been published in a scientific journal or confirmed by others. And although the organs can apparently remove toxins from the body and produce urine, it's not known if they can perform all of the many jobs for which kidneys are responsible.
But if the approach can be used to make human kidneys from cloned human embryos, as the Massachusetts team expects, it could dramatically reduce the need for donor kidneys and transplants in the future, experts said.
More immediately, the findings could influence the bioethical equation in Washington as the Senate considers legislation that would ban the kind of cloning research that led the scientists to create the new organs.
Some people consider research on human embryo clones unethical, saying that it requires the creation of life only to destroy it, and have called for a federal ban on such work. But others believe that such objections might be outweighed if the research were shown to be the most promising means of growing compatible replacement tissues.
While the work remains preliminary – and some scientists suspect that less ethically contentious cells from adults may have the same potential as embryo cells – the study is the first to indicate that cells taken from a newly created clone can be made to grow and work together as an organ and be accepted by the immune system.
" We can say clearly that these kidneys produced urine and survived for several months inside the cows, " said Robert Lanza, chief scientist on the project at Advanced Cell Technology in Worcester, Mass.
Advanced Cell has been criticized in the past for publicizing its results before submitting them for professional peer review – something Dr. Lanza said had not been the company's intention in this case. He answered questions about the work Tuesday, he said, because he wanted to correct errors in news reports that appeared in two London newspapers.
At the same time, Dr. Lanza said he was reluctant to reveal many details of the work because the team hopes to publish the results, and science journals tend not to publish results that have already been publicly released.
Embryos contain so-called embryonic stem cells, which have the potential to turn into all kinds of cells and tissues. Scientists working with mouse, human and monkey embryos have cultivated these cells in laboratory dishes and learned how to get them to morph into specialized cells.
Scientists have not gained that kind of power over cow stem cells. So the Advanced Cell team grew the cloned embryos to an early fetal stage to identify immature cells starting to turn into kidney cells.
John Gearhart, a stem cell expert at Johns Hopkins University, said the results sounded promising. But he said it will be important to prove kidneys can be made from human embryo cells, not just from older fetal cells, because even proponents of human embryo cell research do not favor growing human fetuses for research.