The problem with crafting federal legislation to regulate research into human cloning is that nobody can put their finger on what, exactly, a human being is.
"The problem comes when you ask people with different agendas," explained Alison Taunton-Rigby, chief of Aquila Biopharmeceuticals.
"The way most scientists define humans is after birth, whereas right-to-life people define a fertilized cell as life. If we write language that you can't clone a human being and include the right-to-life definition, that would include anything from a fertilized egg onward."
Terminology proved to be the sticking point in several bills discussed by a panel of scientists and bioethicists this week before the House Subcommittee on Technology. The bills - from the Clinton administration, Representative Vernon Ehlers (R-Michigan), and Senators Christopher Bond (R-Missouri) and John Ashcroft (R-Missouri) - all take a stab at banning the cloning of humans, an act the federal government has struggled to both understand and regulate ever since the February revelation that Ian Wilmut and his colleagues at the Roslin Institute had cloned a lamb using a cell taken from an adult sheep.
Both the Ehlers and Bond bills were drafted before President Clinton impaneled the National Bioethics Advisory Commission in March to research and discuss the ethical and legal issues surrounding the potential cloning of human beings - all toward producing a report within 90 days. Neither bills use terms that are correct from a scientific point of view, and Ehlers' fails to define any terms, says Taunton-Rigby. The administration bill uses the glossary from the Commission report.
The debate over terminology in federal legislation has serious implications for biomedical research. For example, the Ehlers bill would make it "unlawful for any person to use a human somatic cell for the process of producing a human clone." Interpreted strictly, this bill would call most research into question, says Lester Crawford, DVM and director of the Center for Food and Nutrition Policy at Georgetown University. Crawford notes that the process of cloning human cells happens any time doctors grow new human skin cells to graft onto the bodies of burn victims.
"We don't want to wipe out all research to help animals or humans," said Crawford, who was also among the scientists to testify before the subcommittee. "We all agree that trying to do with humans what researchers did in producing Dolly [the lamb] is not safe."
Devising regulation means understanding what exactly it is about Dolly that makes her existence special, says Taunton-Rigby. Cells to produce Dolly came from a 6-year-old sheep - a mature mammal. Researchers had believed that a mature mammal's cells would have differentiated to the point that certain genes would be switched off and could not be reactivated. "What Dolly demonstrated is that, under the right conditions, you could reactivate [the switched-off genes]," Taunton-Rigby said.
What probably makes taking a cell out of a mature human to produce a child unsafe is that researchers won't know what the mutative history of that mature human cell is, notes Taunton-Rigby. Cells in a mature adult have many mutations that are cumulative. For example, long-term exposure to the sun turns off certain genes that preserve the skin's elasticity and keep it soft. As a result, skin becomes leathery and wrinkled. "When you get too many mutations, you get cancer," she said.
Yet the process of cloning and the use of human cells in the process have broad applications in treating disease and chronic conditions. The revelation this week that PPL Therapeutics of Edinburgh has created the first transgenic sheep through cloning may give researchers a chance to eliminate the guesswork involved. For example, when scientists try to genetically engineer animals ordinarily, it's a game of roulette whether the added human genes are, in fact, picked up by their hosts. Cloning should offer scientists a predictable way of getting the human gene to stay inside its animal-embryo cellular host.
Following this research could lead scientists to produce transgenic pigs whose organs contain sugars and proteins that are more readily accepted by human candidates for organ or valve transplants. At the very least, it will provide a more predictable way to produce milk with human proteins that researchers can mine for the purpose of producing drugs to treat such diseases as hemophilia.
Despite these advances, the process of cloning is not a sure thing, even with Dolly, says Crawford. "Wilmut has persistence, techniques and genius, but still, the success rate of this type of cloning is 1 out of 229."
The goal of discussions such as the one before the House is to keep research alive, says Taunton-Rigby. "We're not interested in doing research to help infertile couples - there's already IVF and other research out there for that. But we do not know how to make replacement tissues. If we could do that, then we wouldn't have people on waiting lists for organ transplants."
