Stem-Cell Advance May Be Ethical
Researchers May 28 announced they had found a safe way to transform skins cells into stem cells.
WASHINGTON — An international team of researchers have made a significant improvement on what appears to be an ethical form of stem-cell research.
Scientists have been able to “induce” human skin cells into pluripotent stem cells (iPSC), which are considered just as valuable as embryonic stem cells, although they do not involve the destruction of embryos.
But while the method previously used viral tissue, which isn’t practicable because it could cause genetic damage to the patient, the new method uses protein fragments and carries no threat of genetic damage. It can be used on humans. It is potentially free of many harmful side effects.
“There’s no embryos involved, no cloning,” said an American member of the team, Dr. Robert Lanza, who is chief scientific officer at Advanced Cell Technology and co-author of the report announcing the discovery in the latest issue of Cell Stem Cell. “I’ve been trying for 10 years to stay clear of ethical controversies. And now we’re here.”
In 2006, a Japanese-led team first reprogrammed skin cells into iPSC that, like embryonic stem cells, could then be turned into almost any kind of tissue. However, it did so by marrying four crucial reprogramming genes with part of a virus to get them into skin cells, a method that carried with it the danger of triggering genetic defects.
According to Lanza, the new research has demonstrated — in a lab and not yet on humans — a safer method of getting the genes into skin cells using protein fragments called peptides, which do not alter the target cell’s genetic structure, unlike viruses, which do.
“We showed our iPS cells could do all the same tricks as the embryonic stem cell,” said Lanza, who is Catholic. Indeed, with some applications, like reproducing vascular and retinal tissue, it seems to do better.
But another Catholic biochemical researcher says the research is tainted by its use of tissue derived from an aborted fetal cell line.
“For that reason,” said Theresa Deisher, founder of Seattle-based Ave Maria Biotech, “I would say that the work cannot be considered moral.”
Deisher says that researchers could have done the same research using tissue derived morally and adds that “it would not be immoral to learn how to do something the right way from observing my neighbor doing it in a wrong way.”
However, Father Thomas Berg, director of the Westchester Institute for Ethics and the Human Person in New York, said that “99% of Catholic moral theologians disagree with Dr. Deisher. The main thing here is that this line of research makes feasible a whole field of treatments in an ethical way without using embryonic tissue.”
The problem, says Deisher, is that the reprogramming genes were packaged in HEK 293, a mass-produced cell line derived from aborted fetal material. HEK 293 is used for many studies that have no intrinsic link with embryonic stem cells, but simply because it is cheap and readily available.
Kenneth Miller, a biology professor at Brown University and a frequent guest on network TV, predicts that “within 10 years iPSC will make the use of embryonic stem cells superfluous.”
Lanza said that the Food and Drug Administration’s permission would be sought for clinical trials on humans to begin as soon as next year.
Deisher is dubious about the whole enterprise of iPSC. She says pluripotent stem cells have a tendency to develop tumors. In studies involving embryonic stem-cell treatments used on animals, the treatments cause cancerous tumors. In one experiment, 20% of mice who had embryonic stem cells injected into them to treat Parkinson’s disease developed such tumors.
Far more promising, in Deisher’s view, is research on adult stem cells taken from bone marrow.
Deisher says there are 2,000 “moral” clinical trials under way of treatments using stem cells, and half of these are using stem cells from bone marrow.
Meanwhile, the science community has softened its claims about imminent medical treatments using embryonic stem cells, now that President Obama has reversed his predecessor’s veto on funding.
The Coalition for the Advancement of Medical Research’s CEO, Amy Comstock Rick, for example, says that embryonic stem cells will prove useful not so much for treating diseases, but for studying them. “The idea is that you create Parkinson’s or ALS in a dish so that you can watch and understand the process of the disease,” she said.
But if Father Berg and Lanza are right, iPS cells will have rendered this use unnecessary in a decade.
Steve Weatherbe writes from
Victoria, British Columbia.
- June 21-27, 2009