Cloning, After Hwang
Only three months ago the world
still believed that Dr. Woo-Suk Hwang, a specialist
in veterinary medicine at
In therapeutic cloning, stem cells are culled from six-day-old cloned embryos (killing them in the process). Researchers would then grow tissues from the cells for future use in tissue-replacement therapies (everything from corneal injury to Parkinson’s disease to spinal cord injury). A perfect genetic match to the person who donated the cloned cells, the tissues would not be rejected by the donor’s immune system.
In an article published in the journal Science in February of 2004, Hwang announced that he created human clones (using the same method that gave the world Dolly the sheep), and then derived embryonic stem cells from them — a feat hailed as a scientific advance of epic proportions in the emerging field of stem-cell therapy.
In May of 2005, again in Science, Hwang reported a tenfold decrease in the number of human eggs required for his cloning process. He also claimed to have produced 11 new lines of embryonic stem cells from approximately 30 cloned human embryos — or so his story went.
What does all this mean for the pro-cloning establishment and for embryonic stem-cell research in general?
First, it means the push is on to make therapeutic cloning happen. While most scientific journals agree that Hwang-gate has set the field of therapeutic cloning back for years (never mind that Hwang was “the field”!), the setback has not broken the spirits of would-be cloners. Robert Lanza, medical director of Advanced Cell Technology in Worcester, Mass. (whose own initial forays into cloning in 2001 did not withstand scientific scrutiny), told the Washington Post in January that Advanced Cell will renew their therapeutic cloning efforts.
“The race is back on,” said Lanza, “and the
In addition, we can expect advocates of embryonic stem-cell research to demand access to the so-called “surplus” embryos from in-vitro fertilization. They will continue to insist on the urgency of using these leftover embryos to create new lines of embryonic stem cells, arguing that lines currently available are becoming depleted and showing signs of genetic abnormalities. They will likely suggest that these problems are now only exacerbated by the setback in therapeutic cloning research.
Currently, the federal government
funds research only on those lines of human embryonic stem cells created before
Aug. 29, 2001. Pressure is already growing in Congress to expand the current
policy to include, among other things, the funding of research on these
unwanted embryos. It is deeply disappointing that a number of otherwise pro-life
senators (among them, Republicans Orrin Hatch of
Curiously, however, the vast majority of IVF surplus embryos are designated solely for reproductive efforts. Only 2.8% or roughly 11,000 of the approximately 400,000 spare embryos are designated for possible use in research. Of these, only a small percentage would produce a new stem-cell line. We rightly ask, then, what is motivating the push to sacrifice the in-vitro fertilization embryos if ultimately so few would be available or useful to researchers? Answer: breaking down public and Congressional resistance to using leftover embryos is a crucial step toward garnering public acceptance of the creation (and destruction) of new embryos for research. As they await the heyday of therapeutic cloning, researchers have myriad reasons to embark on a research regime of manufacturing human embryos in vitro on an industrial scale — reasons that often have nothing to do with potential therapies.
Key to this strategy is to convince the American public that if researchers deliberately keep the embryo (cloned or manufactured in vitro) from implanting in a uterus, it lacks moral worth. “If it can’t implant, it’s not human” — such is now the mantra among many embryonic stem-cell research and cloning advocates. Here, however, the non sequitur is obvious: Why should implantation, or any other arbitrary developmental benchmark, designate the threshold of intrinsic and incalculable worth?
More importantly, Hwang’s fraud could constitute a watershed moment for adult stem-cell research. While it is possible today to create embryonic cloned human beings, it might still prove impossible to derive usable and sustainable stem cells from them. The coming years may well be the definitive proving ground in which adult stem-cell research addresses an array of the most troubling diseases more quickly, safely and effectively than by embryonic stem-cell research. Most promising here are stem cells found in human umbilical-cord blood and bone marrow. In fact, a dozen recent scientific studies point to these as likely sources of stem cells just as versatile as embryonic stem cells. On Dec. 20, President Bush signed a vital, but mostly ignored bill (authored by Rep. Chris Smith, R-N.J.) authorizing $344 million for the collection and banking of cord-blood stem cells and their use in stem-cell therapy.
notwithstanding the intrinsic evil of its proposed means, does pursue a
genuinely good end. Would it be possible to pursue this curative potential
while avoiding the ethical pitfalls? As it turns out, the answer is Yes.
One of the most promising
approaches is called cell reprogramming. In reprogramming, scientists propose
to take any cell in our body and reprogram the nucleus of the cell such that
the result is the equivalent of an embryonic stem cell — like reformatting the
hard drive of a computer. The beauty of
reprogramming is that it holds out the same promise as therapeutic cloning —
tailor-made stem cells to match the patient — without killing embryos. In
August of 2005, Dr. Kevin Eggan of
Altered nuclear transfer is another approach. This technique proposes to take the same technique used in cloning (transfer of a body cell nucleus to an egg cell with its nucleus removed), but this time for a good end. In altered nuclear transfer, the nucleus of a normal adult body cell is catastrophically altered to impede normal embryo formation. This nucleus is then implanted into the enucleated egg. The product of this procedure — unlike cloning — would not be an embryo, but a disordered biological artifact, capable of yielding cells as versatile as embryonic stem cells, but otherwise akin to a tumor.
In October 2005, the journal Nature reported that researchers at the
Massachusetts Institute for Technology had, for the first time, used altered
nuclear transfer in laboratory mice to derive a line of “fully competent” cells
equivalent to mouse embryonic stem cells. This process is a broad conceptual
proposal originated by Dr. William Hurlbut of
Today we stand at the threshold of a future in which embryo-destructive research could become commonplace. Once our nation vouchsafes the creation and destruction of human life for research, there will be no “slippery slope” to go down, because we’ll already be at the bottom. To avoid such a future, we must demand that lawmakers pursue a complete federal ban on human cloning. Such bans should be pursued simultaneously at the State level. We can also urge our representatives to enact legislation that will open up federal funding for research into alternatives such as altered nuclear transfer and reprogramming. Research into these alternatives, along with continued advances in adult stem-cell research, may well render moot the putative need for therapeutic cloning and increased lines of embryonic stem cells. In educating ourselves on these issues, and bringing that knowledge to the voting booth, we can forge a future which protects human embryos from the demands of unprincipled scientific research.
Legionary Father Thomas Berg
is associate professor of moral
philosophy at the Center for Higher Studies of the Legion of Christ in
Thornwood, NY, and executive
director of the Westchester Institute for
Ethics & the Human Person.
- January 29-February 4, 2006