Hundreds of years ago, under cover of darkness. Shrouded in secrecy. Breaking the law.
This is what human biological science used to look like. Once upon a time, seekers of knowledge in the natural world (Leonardo Da Vinci among them) risked their careers and lives digging up cadavers to peek inside them and try to discern how the human body functions. At the time, this act was seen as a violation of human dignity, immoral, and, of course, illegal.
That was then. This is now: biologists are once again caught in a moral dilemma that threatens their scienceand puts them under constant legal crossfire. While the dissection of a dead, thus de-souled, human body is no longer viewed as a scientific travesty, the disassembly of human embryos has for years been generating enormous controversy for researchers, politicians, and the public.
In 2001, President Bush signed a law restricting the use of federal funding for embryonic stem cell (ESC) research to cell lines that had already been extracted from unwanted IVF (in vitro fertilization) embryos in fertility clinics. In March 2009, President Obama issued an order destrictifying Bush’s policy so that new embryo lines could be opened up to researchers. But in August 2010, a federal judge made a preliminary ruling against the more lenient policy in court, citing a 1996 ban on federal funding for any project that destroys human embryos. And this May, a federal appeals panel overturned the judge’s temporary injunction restricting federal funds from being used while the judge makes a final ruling.
Physician and ethicist William Hurlbut was on the President’s Council on Bioethics when lawmakers were considering whether to open up new embryonic stem cell lines for research purposes. “Contrary to what’s printed in the press, the group advising President Bush was not a ‘rubber stamp’ council,” said Hurlbut recently via phone, pausing to clarify that his position on the council was not a political appointment, “I thought it was clear that the science was worth investigating—stem cells are what naturally give rise to cells of every other type (cell, tissue, and organs), and many scientists then saw ESC research as the fast-track to lifesaving cures and technologies. But I also felt like it raised a lot of troubling issues. Traditional stem cell research—even research that might result in needed cures for the dying and infirm—also means relegating millions of living human embryos to the status of raw materials.”
The issue is far more complex than most defenders and supporters of ESC science make it out to be, Hurlbut says. Even he didn’t know his own mind until he was on the President’s council and really had to think about why dismantling unwanted embryos should give scientists (and the public) pause. “Embryos are microscopic,” Hurlbut said, “an eight-celled embryo can easily rest on the sharp tip of a pin, and they certainly don’t look like unique individuals… it’s kind of hard for people to relate to a tiny clump of dividing cells. But there’s a big difference between living embryos and every other type of cell in the human body.”
Explaining that difference required about an hour of poignant discussion of what it means to be human, in the first place. Fortunately, the essential distinction Hurlbut illustrated can be whittled down to a single elegant word: potential.
“When scientists discuss the ‘building blocks’ of life in terms of DNA, amino acids, proteins, etc., none of these materials, when stripped from their surrounding elements, have the potential to become organisms that have the indwelling powers to develop as a human organism,” Hurlbut said. “Even gametes—the sperm and the egg—are alive in a body as cells, but they aren’t living beings. Only when they join together to create something that has a special kind of organization—an organization that will eventually give rise to a fully formed, living, breathing baby with fingers, toes, a heart, a brain, and reproductive organs of its own—can a single cell be considered a living thing. It’s this active power to develop in a human way that endows the human embryo with its unique moral status’. This simple 1+1 of sperm and egg creates the infinity and eternity of a human being.”
The moral controversy over embryonic stem cells is based on the fact that to get these cell lines a living human embryo is destroyed. However, to get the true equivalent of embryonic stem cells, and to keep from having to destroy human embryos, in 2006 scientists proposed a way to modify the nuclei of adult cells so that they functionally double-back to a state of pluripotency (or the prenatal ability to give rise to a wide array of cell types). To do this, they modified a technique known as SCNT (Somatic Cell Nuclear Transfer), in which the nucleus of the adult cell, which contains its DNA, is removed from the cell body and implanted into an egg cell that’s had its own nucleus removed. The egg then has a full set of DNA and, after some electrical stimulation, starts to divide like an IVF egg and forms an embryo.
This embryo creation method is also called cloning, and as Hurlbut points out, it’s exactly the same method that was used to create Dolly the Sheep, but scientists haven’t yet gotten it to work with human cells. If someday they can get adult cells to produce embryos, these may be more promising than IVF embryos in some technical ways (like medical applications in which cures made from a person’s own DNA would be favorable over a stranger’s), but the process still creates and destroys a viable embryo that could have gone on to become a human. So for both sides of the stem cell debate, this, too, may be stalemate.
What Hurlbut wants to do is help researchers plot a path around all the ethical tripwires. To do that, he’s designed and proposed a morally sound method for stem cell research called Altered Nuclear Transfer (ANT). Using ANT, all scientists have to do is insert an extra step into the standard cloning procedure. This extra step is to silence mRNA in the cytoplasm of the egg so that when the nucleus is transferred into the egg no embryo is produced. Although the embryo still produces pluripotent stem cells, it doesn’t have the organization—that precious potential—to create life.
While Hurlbut’s solution could be a way to move stem cell science out of the courtroom and back into the lab full time, Altered Nuclear Transfer needs more research, more support, and of course, more funding before it can become a standardized method of stem cell production. In the meantime, (for now at least), ESC research has the federal thumbs up, so scientists may feel less urgency to pursue ANT and other alternatives.
“My whole orientation and alignment is to help extend the circle of agreement on this topic, and ANT has been found morally acceptable by some of the most conservative religious leaders in the country,” says Hurlbut. “I just don’t think we’re ever going to solve the debate over embryo destruction, and having this moral and political tug of war is damaging to our nation’s need for unity—as well as a sense of nobility in science.
“The fact is, morality is essential for our society to exist, and most people will agree that human beings are an exceptional kind of creature, endowed with a sense of love, justice, and beauty, and that these things set us apart from the rest of the animals on earth,” Hurlbut says. “But humans aren’t just a species, they’re individuals. And if we believe that all human individuals have the right to live good, meaningful lives, then we must have a way to recognize those individuals. So where and when does our love for each other, and our love from God, actually start? You and I were once a clump of two, four, eight cells in a fallopian tube in your mother. Can we really say that there’s a single point in the dividing, implanting, and diversifying of embryonic cells that an unrepeatable human is endowed with morality and dignity? Human life is anunbroken continuity from fertilization to natural death. I believe that once we are initiated as living human organisms, we are worthy of full respect, protection and nurture as the image of God.”
Fortunately for embryonic stem cell researchers, they don’t live in a time at which any of them have to meet for midnight digs through the dumpsters behind fertility clinics, nor even duck their heads in public concerning the nature of their work. But the laws that govern the funding they need to pursue this work are being written with erasable ink. Hurlbut hopes that more of them will want to look for ESC alternatives, if for no other reason than they’ll be building their labs on higher, more solid moral ground. The big shift hasn’t happened yet—but there’s potential.