18 May Biologist who cloned Dolly the sheep believes therapeutic cloning will gain acceptance
Madison, Wis. – Ian Wilmut doesn’t shy away from the term “cloning,” even with the controversial ethical connotations that come with it, but he believes in time the technique he developed to create Dolly the sheep will gain more public acceptance in the development of human therapies, just as human embryonic stem cell research has.
Wilmut, a biologist with the Scottish Center for Regenerative Medicine at the University of Edinburgh, was in Madison to lecture on the science of that cloning technique, also known as somatic cell nuclear transfer, and its potential for biomedical research. While it remains controversial, especially in the United States, Wilmut said it has the potential to advance scientific understanding and develop better treatments for ALS, and Parkinson’s disease, psychiatric diseases, cardiomyopathy, and cancer.
Wilmut believes the shift in public attitudes in favor of embryonic stem cell research might bode well for somatic cell nuclear transfer, which has more public support in the UK than in the United States.
To gain that acceptance, he said it’s important that people understand the technique and what it’s intended to achieve, especially the difference between therapeutic cloning and cloning a human being.
“I think it’s important to recognize that to some people, these are concerning, frightening, and offensive ideas, and we have to respect that,” he said. “In all of these cases, it’s absolutely essential to define clearly what you have in mind, and then people can make their individual judgments, and if you just describe it casually, you may mislead people and get the wrong conclusions.”
The technique
Somatic cell nuclear transfer is a laboratory technique for creating an ovum, or egg cell, with a donor nucleus. While it can be used as the first step toward reproductive cloning, which is banned in the United States, it also can be used in embryonic stem cell research or in regenerative medicine, where it is referred to as therapeutic cloning.
In the nuclear-transfer process, the nucleus of a somatic cell, a body cell other than a sperm or egg cell, is removed, as is the nucleus of an egg cell. The nucleus of the somatic cell, which contains the organism’s DNA, is then inserted into the “enucleated” egg cell and is reprogrammed by the host cell.
The egg cell, which now contains the nucleus of a somatic cell, is stimulated with an electric shock, which essentially serves the same purpose as sperm, and the cell begins to divide. The single cell eventually will form a blastocyst, or early-stage embryo, with almost identical DNA to the original organism.
The objective of this procedure is to obtain stem cells that are genetically matched to the donor organism, which is not controversial in animal cloning.
In developmental biology, the therapeutic cloning of human cells is what generates controversy. In 2005, the Wisconsin Legislature passed a ban on the cloning of human embryonic stem cells for research purposes, expressing the view of many that human embryos should not be used or created for scientific experimentation.
Gov. Jim Doyle, who supports cloning for therapeutic purposes, but not for reproductive purposes, vetoed the bill.
Ethical explanation
Wilmut, who was in Madison in part to lecture and in part to build relationships between the University of Wisconsin-Madison’s new Stem Cell and Regenerative Medicine Center and the Center for Regenerative Medicine in Edinburgh, took some time to explain his own ethical considerations.
He said the early-stage embryos that stem cells would be derived from are about 0.2 millimeters in size, comparable to a grain of salt or sand. The embryos are about six days old, have about 200 cells, and are several weeks away from forming a central nervous system. In his view, what is fundamental to being human, what signifies life, is the ability to feel and express emotion – to laugh, to cry, to love – which the young embryo lacks.
“It’s not that the embryo has lost that ability, it’s that it hasn’t gotten there,” he explained.
One day, there may even be a process that will be used instead of somatic cell nuclear transfer. At some point, Wilmut said a patient who needs dopamine neurons to treat Parkinson’s disease may be able to visit a clinic, have cells removed from his own skin, and be treated in ways that come from cloning. The cells would be reprogrammed without using nuclear transfer and without involving an embryo, avoiding ethical concerns that come with it.
More oversight needed
Until that day arrives, nuclear transfer could be fighting uphill battle for public support.
Timothy Kamp, an associate professor of medicine at UW-Madison, said the biology revealed from somatic cell nuclear transfer will lead to new tools and, potentially, new therapeutic applications, but it will require more oversight than other avenues of discovery.
“I think it’s possible, but I think it’s going to continue to be something that is going to need more oversight than other potential areas of biological research because of the potential for other things to be done that I think a majority of people would agree are ethically less acceptable,” he said.
Susan Carlson, director of operations for WiCell, has traveled across the state to explain embryonic stem cell research at public forums. She said nuclear transfer may end up being an accepted technology, but the American public isn’t yet ready to accept it.
“I think we need to first get people more comfortable with the idea of embryonic stem cells and what the potential is there,” she said, “before we start moving into therapeutic cloning as a readily accepted technology.”
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