On the path to cloning?

Cloning is making its way back into the news, with announcements by a Massachusetts biotechnology company, Advanced Cell Technology.

ACT claims it has created "normal" cows through cloning and is making public the results of its successful human embryo cloning effort -- and the "recipe" for creating cloned embryos. The company says it created the clones for research into how it might produce stem cells for therapeutic purposes, and has no intention of allowing any of the embryos to be implanted into a woman's womb to create a pregnancy.

But the announcement of a successfully cloned human embryo, even for research purposes, rekindles the fear that cloning identical copies of humans cannot be far off. The technical reality is still a distant prospect but the successful cloning of embryos is another step along the path. What are the appropriate limits on stem cell research and the application of cloning technologies?

Therapeutic versus reproductive cloning

ACT's research focuses on so-called therapeutic cloning, where a cloned embryo is made using the DNA of a patient who could benefit from a stem cell transplant. The cloned embryo would then be allowed to divide only a few times, after which the embryonic stem cells would be collected and used to grow genetically-matched tissues or specific cell types needed to treat the same patient.

Cloning embryos for their stem cells is controversial for two reasons.

For many people the intention for which embryos are created is critically important in thinking about the ethics of their use. For them, using embryos that were created in fertility clinics -- originally intended for use in reproduction -- is more acceptable than creating embryos expressly for the purpose of research. In this view, creating embryos expressly for research purposes does not treat them with adequate respect. But for others, the moral costs of creating early stage embryos exclusively for research purposes are outweighed by the promise of significant medical benefits.

While therapeutic cloning is morally very different from trying to create an identical copy of a human through reproductive cloning, the newly published techniques used to create the embryos would be exactly the same. But instead of collecting stem cells, doctors would place the cloned embryo in a woman's uterus in the hope that it would result in a pregnancy and the birth of a cloned baby. For some, this implies that therapeutic cloning will inevitably lead to reproductive cloning.

Stopping the slippery slope

If we believe that the benefits of therapeutic cloning outweigh its moral costs, how can we prevent the same technology being used to clone humans? As is the case for many medical technologies, it is not cloning techniques that are unethical, but some of their potential applications. For example, we reject the transplant of organs from executed prisoners, but we don't prevent it by banning organ transplantation. The challenge for stem cell research policies is to create appropriate parameters to allow its benefits while preventing abuses or unethical applications.

The Bush administration had an important opportunity to set federal policy when it considered whether to allow funding for stem cell research, and if so, with what limitations.

Such decisions often have far-reaching implications -- even though they technically apply only to publicly funded research, they tend to set the standard for practice in both publicly- and privately-funded research. By limiting funding to only those cell lines that existed as of August 2001, the administration was silent about what rules or parameters ought apply to the creation of embryos -- whether by in vitro fertilization or cloning technologies -- leaving a gaping policy vacuum.

We're long overdue for a reasoned public debate on how far stem cell research ought to go, and how to limit the creation of embryos to ways that our society deems acceptable.

If we want to realize the benefits of therapeutic cloning but prevent reproductive clones, then we'll have to level serious penalties against anyone who allows cloned embryos to develop past a certain point, or to be implanted in a woman's uterus. This could include everything from harsh fines to long prison sentences, or both.

There is every reason to think we can distinguish therapeutic from reproductive cloning and create policies that make the distinction stick. Clearly the science will move forward, but with no obvious brakes or steering. A workable policy is key to determining how far we go and how fast we get there.