Written Testimony of David A. Prentice, Ph.D.
Senior Fellow for Life Sciences, Family Research Council
Founding Member, Do No Harm: The Coalition of Americans for Research Ethics
Committee on Health and Aging, Ohio House
June 15, 2011
Mr. Chairman, the Distinguished Ranking Member, and Honored Members of the Committee.
Thank you for the opportunity to testify on this important legislation.
I am testifying in SUPPORT of HB 171.
I am a cell biologist, currently working for a policy think tank in Washington, D.C. For the previous 20 years I was Professor of Life Sciences at Indiana State University and Adjunct Professor of Medical & Molecular Genetics at Indiana University School of Medicine, and I have done federally-funded laboratory research, lectured, and advised on these subjects extensively, in the U.S. and internationally. I was selected by the Bush President's Council on Bioethics to write the comprehensive review of adult stem cell research< for the Council's 2004 publication "Monitoring Stem Cell Research".
Human cloning is human asexual reproduction, termed "asexual" because it does not involve the combining of egg and sperm to form an embryo. The focal technique to accomplish this is somatic cell nuclear transfer (SCNT)�"introducing the nuclear genetic material from one or more human somatic (body) cells into a fertilized or unfertilized egg cell whose nuclear genetic material has been removed or inactivated, producing a human embryo who is virtually genetically identical to an existing or previously existing human being.
Proponents of human cloning hold out two hopes for its use: (1) creating live born children for infertile couples or those grieving over the loss of a loved one, so-called "reproductive cloning" (live birth cloning), and (2) promises of medical miracles to cure diseases by harvesting embryonic stem cells from cloned embryos created from patients, euphemistically termed "therapeutic cloning" (more properly termed research cloning.)
Biologically the process of cloning (somatic cell nuclear transfer; SCNT) produces a zygote, a one-celled embryo, at the starting point for development. As the President's Council on Bioethics noted, "The first product of SCNT is, on good biological grounds, quite properly regarded as the equivalent of a zygote, and its subsequent stages as embryonic stages in development."
Likewise, the National Institutes of Health has affirmed that SCNT cloning produces an embryo.
The National Academy of Sciences noted the following:
"The method used to initiate the reproductive cloning procedure is called nuclear transplantation, or somatic cell nuclear transfer (SCNT). It involves replacing the chromosomes of a human egg with the nucleus of a body (somatic) cell from a developed human. In reproductive cloning, the egg is then stimulated to undergo the first few divisions to become an aggregate of 64 to 200 cells called a blastocyst. The blastocyst is a preimplantation embryo that contains some cells with the potential to give rise to a fetus and other cells that help to make the placenta. If the blastocyst is placed in a uterus, it can implant and form a fetus. If the blastocyst is instead maintained in the laboratory, cells can be extracted from it and grown on their own."
The equivalence of the embryo, as zygote and blastocyst, has also been noted by the National Academy of Sciences, which has noted that the embryos produced by fertilization and the embryos produced by SCNT cloning are indistinguishable.
Fertilization compared to Cloning (Somatic Cell Nuclear Transfer, SCNT)
Both sexual reproduction (fertilization, egg+sperm) and asexual reproduction (cloning, i.e., somatic cell nuclear transfer) produce a human embryo, a living human organism, species Homo sapiens.Cloning (SCNT) creates an embryo, not stem cells.
This is the same cloning technique, somatic cell nuclear transfer (SCNT), that was the process used to create the cloned sheep Dolly.
We need to be clear on the terms. Both "reproductive" and "therapeutic" cloning use exactly the same techniques to create the clone, and the cloned embryos are indistinguishable. The process, as well as the product, is identical. The only distinction is the purpose for use of the embryo--either transfer to a uterus in the hopes of a live birth, or destruction in the hopes of a medical miracle.
The technique of cloning is finished once that first cell, the one-celled embryo (zygote) is formed.
Anything beyond that step is simply growth and development. And despite attempts to employ various euphemisms, scientifically, genetically, what is created is a human being; its species is Homo sapiens, it is neither fish nor fowl, monkey nor cow�"it is human. The use of disingenuous euphemisms to describe the embryo as something other than an embryo likewise are not scientific, and diverge from the accepted definitions as put forth by the National Academy of Sciences, the National Institutes of Health, and others, including well-known proponents of human cloning.
This fact is also made clear by leading proponents of embryo research:
"Moreover, because therapeutic cloning requires the creation and disaggregation ex utero of blastocyst stage embryos, this technique raises complex ethical questions."
"[Therapeutic cloning] requires the deliberate creation and disaggregation of a human embryo."
Q: The people who use nuclear transfer generally say that the technique is optimized for producing the stem cells rather than making babies. They would not want to equate this with the process that produces embryos that were fit for implantation, and they'd argue that they're using the reproductive process differently ...
A: (James Thomson) "See, you're trying to define it away, and it doesn't work. If you create an embryo by nuclear transfer, and you give it to somebody who didn't know where it came from, there would be no test you could do on that embryo to say where it came from. It is what it is. It's true that they have a much lower probability of giving rise to a child. ... But by any reasonable definition, at least at some frequency, you're creating an embryo. If you try to define it away, you're being disingenuous."
The assumption that cloning (SCNT) will produce matching tissues for transplant that will not be rejected is still theoretical. When tested in mice in 2002, the ES cells from the cloned mouse embryo were rejected by the genetically-identical host:
"Jaenisch addressed the possibility that ES clones derived by nuclear transfer technique could be used to correct genetic defects& However, the donor cells, although derived from the animals with the same genetic background, are rejected by the hosts."
In 2008, another lab attempted to treat Parkinson's in mice, first cloning the mice, then harvesting stem cells from the cloned embryos. When placed back into the mice, there was some improvement in their condition, but 1 out of 6 mice showed "graft overgrowth" in their brains, most of the cells produced showed chromosomal abnormalities, and the authors noted that it was "technically complex" and required a huge number of eggs to get a single dish of cells. It is unknown whether tumors might have developed later in other animals as the experiment was terminated early. Moreover, the data are equivocal in terms of transplant matching, due to the fact that the brain is an immuno-privileged site (very little immune reaction).
In fact, the best results to date (even though equivocal) in animal studies actually come from gestating cloned animals to the fetal stage and then harvesting tissue stem cells.
The idea of therapeutic cloning--cloning an individual to create embryos, from whom stem cells are harvested--was already outdated in 2008 and the science superseded by better, easier scientific methods for matching stem cell production.
Moreover, the assertion that cloning is the only method for preventing immune rejection of transplanted embryonic stem cells is completely false. In an article published March 18, 2002 (Abate, San Francisco Chronicle), researchers with Geron Corp. and with Advanced Cell Technologies admitted that there are ways to prevent rejection of transplanted cells without therapeutic cloning, but that "that message has not gotten out," and that "the need for cloning to overcome immune system rejection has been overstated."
The report goes on to note "the scientific community has put out the message that a ban on therapeutic cloning will prevent researchers from solving the immune-system problem--an argument that seems at best a stretch, and at worst, a deception."
Other scientists have admitted in testimony that therapeutic cloning will not prevent transplant rejection of cloned tissues:
"There is no question in my mind that the possibility exists that if you are doing an egg donor, and nuclear transfer into an egg, that there possibly exists that that cell -- that the embryonic stem cells derived from that could be rejected. Absolutely." Dr. John Gearhart, Johns Hopkins
"I should say that when you put the nucleus in from a somatic cell, the mitochondria still come from the host." He concluded, "And in mouse studies it is clear that those genetic differences can lead to a mild but certainly effective transplant rejection and so immunosuppression, mild though it is, will be required for that." Dr. Irving Weissman, Stanford
Dr. James Thomson, who originally isolated human embryonic stem cells, has stated in one of his published papers that cloning is unlikely to be clinically significant.
"[T]he poor availability of human oocytes, the low efficiency of the nuclear transfer procedure, and the long population--doubling time of human ES cells make it difficult to envision this [therapeutic cloning by SCNT] becoming a routine clinical procedure..."
Other leaders in the embryonic stem cell field have also published similar views, including Australia's Alan Trounson:
"However, it is unlikely that large numbers of mature human oocytes would be available for the production of ES cells, particularly if hundreds are required to produce each ES line... In addition, epigenetic remnants of the somatic cell used as the nuclear donor can cause major functional problems in development, which must remain a concern for ES cells derived by nuclear transfer. ...it would appear unlikely that these strategies will be used extensively for producing ES cells compatible for transplantation."
The evidence from animal studies indicates that it will indeed require a tremendous number of human oocytes (eggs) to produce even one ES cell line from cloned embryos. Dr. Peter Mombaerts, who was one of the first mouse cloners, estimates that it will require a minimum of 100 eggs. The reports from South Korea of human embryo cloning have been shown to be a fraud, but even so the news stories indicate that the researchers obtained over 2,200 human eggs for use in their unsuccessful experiments, through paying women to go through the risky procedures of egg harvesting, as well as through coercion of students. At a rate of 100 eggs per patient, to treat, theoretically, the 18 million diabetics in the U.S. by this technique would require at least 1.8 billion human eggs.
The 2008 report of the first and only documented success at cloning human embryos was by the California company Stemagen (in which one of the scientists, Wood, admitted that he cloned himself), and did not result in any cells obtained from the clones; they attributed this sole cloning success to use of fresh, high-quality human eggs from a nearby fertility clinic with which they were associated. The only reported case of obtaining any embryonic stem cells from cloned primate embryos was in 2007 with monkeys. In this case it took over 100 eggs each to produce only 2 ESC lines (one of which had chromosomal problems.) The group had worked for almost 10 years, using around 15,000 monkey eggs. Dr. Rudolph Jaenisch, a cloning scientist at Massachusetts Institute of Technology, noted:
"The procedure is very complicated, he said, and has ethical implications because the embryos have to be destroyed to obtain the stem cells. "Nobody in their right mind would think this is useful for therapies," Dr. Jaenisch said. He also noted that the process requires more than 100 oocytes to create a single stem-cell line and that the supply of human oocytes available for research is limited."
In a recent profile of Dr. Jaenisch, he discussed the uselessness of so-called "therapeutic cloning" and how the technique is of no practical relevance:
"Ten years ago, we talked about the potential of nuclear transfer for therapy. But it turns out the technique was of no practical relevance. You would never do it in humans for a number of reasons. First, it's very inefficient. With mice, that doesn't matter because we can do hundreds of transfers to get a few mice. But human cloning is another order of magnitude more difficult than in mice. And people can't even get the eggs to practice [on]. My former student Kevin Eggan, along with his colleagues at Harvard, spent years putting in place a protocol to get volunteer egg donors. They spent a couple hundred thousand dollars just in advertising. And I think they got one or two donors.
Kevin's postdoc, Dieter Egli, who went to Columbia, told me that he got a couple [of] human nuclear transfers going, but they all arrested at the 6- or 8-cell stage."
The problem with finding enough human eggs for cloning experiments has led to an interesting alliance of pro-choice and pro-life feminists, forming a group called Hands Off Our Ovaries (see http://handsoffourovaries.com). The group spans the political and ideological spectrum, but are united against this risk of using women and their bodies as raw materials for experiments, including harvesting eggs for cloning experiments.
Moreover, allowing "therapeutic" cloning while trying to ban reproductive cloning is unfeasible, and will simply hasten development of the process supposedly to be banned, reproductive cloning. Again, honest proponents of cloning have noted this themselves:
"It is true that the techniques developed in CRNT [cell replacement through nuclear transfer, aka therapeutic cloning] research can prepare the way scientifically and technically for efforts at reproductive cloning."
The American Society for Reproductive Medicine (ASRM), the largest professional organization with expertise in reproductive technologies, says that SCNT is simply the procedure that clones embryos for whatever purpose (whether for starting a pregnancy or destroying for research). And ASRM concedes that if cloning for research is allowed, that research will be used to refine the process and will make it easier to perform "reproductive" cloning:
"If undertaken, the development of SCNT for such therapeutic purposes, in which embryos are not transferred for pregnancy, is likely to produce knowledge that could be used to achieve reproductive SCNT."
In terms of the egg issue and numbers involved, one proposal has been to use animal eggs instead, to produce a human-animal hybrid or "chimera". Some have claimed that this is improbable science, yet in 2003 a Chinese lab reported success using rabbit eggs to produce cloned animal-human hybrids, and the U.K. in fact issued three licenses to begin such research and in 2008 one lab reported success at creating human-animal hybrid embryos using this technique with cow eggs, though they did not obtain any cells from the cloned embryos. Some laboratories, such as Advanced Cell Technology, have failed to produce cells from human-animal hybrid embryos and concluded that the technique is implausible. It should be noted that the same lab also failed to produce cells from fully-human clones. Such experiments, while ethically questionable and unlikely to produce useable results, are still not impossible, as noted above.
Recent advances in stem cell research have overtaken the efforts at cloning. Scientists have now shown that there is an easier, less expensive and more direct method to produce embryonic-type stem cells from a patient's own tissue, with a real potential for a tissue match.. These cells, termed iPS cells (induced Pluripotent Stem cells) were first developed in 2006 in mice by the Japanese scientist Shinya Yamanka.
Yamanaka's lab and the lab of Thomson in the U.S. showed in November 2007 that this same technique could work for humans as well, easily producing human iPS cells directly from human tissue. The straightforward technique involves adding 3-4 genes directly to a human cell such as a skin cell, reprogramming the cell such that it behaves like an embryonic stem cell, yet without use or production of an embryo, eggs, or cloning.
Thomson's group in their paper showing this first production of human iPS cells noted:
"The human iPS cells described here meet the defining criteria we originally proposed for human ES cells (14), with the significant exception that the iPS cells are not derived from embryos."
In a subsequent report, Thomson (who was the first successfully to grow human embryonic stem cells in the lab) noted:
"Recently, adult human cell lines were reprogrammed to an ES cell state (induced pluripotent stem cells, iPS cells) (40, 41). These cells possess the therapeutically desired characteristics of ES cells, namely indefinite self-renewal and pluripotency, without the requirement of human embryo destruction."
Hearing of the impending announcement about iPS cells in 2007, Prof. Ian Wilmut, cloner of Dolly the sheep, publicly forsook cloning technology and his UK license allowing him to clone human embryos, to work on the new iPS cell technology.
Subsequently, other groups have verified the ability to obtain iPS cells, including from human tissue, and improved on the technique, making it even safer.
Jaenisch's group has also shown that iPS cells are effective at improving the health of mice with sickle cell anemia. The iPS cells succeeded where cloning had previously failed.
Discussing this real advance with iPS cells in mice, the researchers noted:
"This demonstrates that IPS cells have the same potential for therapy as embryonic stem cells, without the ethical and practical issues raised in creating embryonic stem cells," says Jaenisch.
Townes says he and Jaenisch initially collaborated on a project that used nuclear transfer to make corrected stem cells, a process called therapeutic cloning. But the experiments failed, he says, because nuclear transfer was too inefficient to produce the needed cells. The iPS cell technique "is amazingly efficient," he says.
Thus, iPS cells fulfill the desire to create embryonic-type stem cells, with the potential for transplant match, but do so without the use of embryos, eggs, or cloning.
Since November 2007 and the first human iPS cells, groups have created over 600 different human iPS cell lines, including over 50 different lines directly from patients with different diseases. In 2008, a Japanese news agency announced that Dr. Yamanaka was preparing to produce iPS cells from a group of 60 patients with various diseases, in order to study disease development and potential treatments in the laboratory.
Ian Wilmut (cloner of Dolly the cloned sheep) has created iPS cell lines from patients with motor neuron disease, to study the disease in the laboratory and possibly to match the patient. Prof. Wilmut had been trying to obtain such cells from cloned human embryos for years, yet succeeded in a short period of time with the iPS cell technique. According to Wilmut:
"This is so much simpler a procedure, quite apart from the ethical issues.
Some have claimed that SCNT cloning is needed to replace stocks of human embryonic stem cells from IVF embryos. In March 2009, President Obama issued an executive order, and NIH issued guidelines, that allow many more human embryonic stem cell lines to be produced, and allowing federal taxpayer dollars to fund embryonic stem cell research with these newly-established ESC lines. It is worth noting, however, that scientists were most concerned that the oldest, best characterized and reliable stem cell lines, previously funded, be approved; the stocks of those cells obviously did not need to be replaced. The NIH has at this date approved 122 embryonic stem cell lines for federal funding, including the oldest and best characterized lines.
Stem cell science has moved beyond the outdated cloning technique. The only reason at this point to practice SCNT cloning would be if the researcher wished to produce cloned embryos for gestation and birth.
Stem cell science has also moved well beyond cloning and hybrids in terms of real treatments for patients.
A wealth of scientific papers published over the last few years document that adult stem cells are a much more promising source of stem cells for regenerative medicine. Some adult stem cells actually do show pluripotent flexibility in generation of tissues, meaning that they can generate most or all of the different tissues of the body. These include adult stem cells from various sources, including bone marrow, peripheral blood, placental amniotic membrane. As just one example, Wake Forest researchers found that amniotic fluid and placenta contains stem cells that can be easily harvested, show extended growth in culture, show similar flexibility to form other tissues of the body, and can be transplanted without tumors, emphasizes the range of abilities that adult and tissue stem cells possess.
Many references also show that adult stem cells can multiply in culture, retaining their ability to differentiate, and providing sufficient numbers of cells for clinical treatments. Two 2010 papers document factors that stimulate adult stem cells from bone marrow and cord blood to significant growth in numbers.
The factor pleiotrophin significantly stimulated growth and expansion of bone marrow and cord blood adult stem cells, describing it as a "regenerative growth factor." And Boitano et al. discovered a factor they called StemRegenin1 (SR1) that produces robust expansion of bone marrow and cord blood stem cells, what some experts labeled the "holy grail" of hematopoietic transplant medicine.
The chart shows examples (not all-inclusive) of tissues from which adult stem cells have been isolated, as well as some of the derivatives from those stem cells. Many references also show that adult stem cells can multiply in culture, retaining their ability to differentiate, and providing sufficient numbers of cells for clinical treatments. Adult stem cells have been shown to be effective in treating animal models of disease, including such diseases as diabetes, stroke, spinal cord injury, Parkinson's disease, and retinal degeneration.
But of even greater significance, adult stem cells are already being used clinically to treat many diseases in human patients. These include published results with patients, using adult stem cells as reparative treatments with various cancers, autoimmune diseases including multiple sclerosis, lupus, juvenile diabetes and arthritis, anemias including sickle cell anemia, and immunodeficiencies. Adult stem cells are also being used to treat patients by formation of cartilage, growing new corneas to restore sight to blind patients, treatments for stroke, and several groups are using adult stem cells with patients to repair damage after heart attacks. Early clinical trials have shown initial success in patient treatments for Parkinson's disease and spinal cord injury (for a list of conditions already treated in human patients by adult stem cells and cord blood stem cells, please see http://www.stemcellresearch.org/facts/treatments.htm). An advantage of using adult stem cells is that in many cases the patient's own stem cells can be used for the treatment, circumventing the problems of immune rejection, and without tumor formation. The citations given above for adult stem cells are only a sampling, including some more recent references. Other listings can be found in the 2004 President's Council Report and in a January 2006 review in the Journal of Investigative Medicine.
In terms of setting the record straight, the complete and accurate record from peer-reviewed publications shows that adult stem cells have already successfully improved patient health. A completely-referenced defense of the use of adult stem cells for treatments that improve patient health has been published recently by the journal Science This information has been validated by several other peer-reviewed papers documenting improvement in patient health after adult stem cell treatment, including a paper published February 26, 2008 in the Journal of the American Medical Association reviewing 10 years of 69 published< patient trials that document the benefit to patient health of adult stem cells for autoimmune conditions such as multiple sclerosis, juvenile diabetes, systemic lupus, and Crohn's disease, as well as acute and chronic heart damage and peripheral vascular disease.
Peripheral artery disease has now been treated successfully in a number of patients, restoring circulation to limbs and preventing amputation.
Other recent peer-reviewed publications document patient improvement with adult stem cells in treatment of spinal cord injury, multiple sclerosis, as well as type I (juvenile) diabetes and type II diabetes, as well as end-stage liver disease. Adult stem cells have also shown documented success at treating chronic heart failure in 191 patients, and restoring sight to blind patients with corneal blindness, even after 50 years of blind
Tissue engineering using the patient's own adult stem cells has been used successfully in the production of a new trachea or windpipe; the group reports unpublished results that within the past year they have improved the technique using in vivo regeneration of tissue, successfully treating three more patients, including two patients with tracheal cancer. A different group has constructed functional urethras for patients.
In another first, Adult stem cells have been used successfully to treat children with a deadly skin disease known as recessive dystrophic epidermolysis bullosa (RDEB; one of the most severe forms of epidermolysis bullosa, a set of genetic skin diseases.) EB affects the skin and lining of the mouth and esophagus, causing skin to blister and scrape off with the slightest friction. The blistering, peeling skin also leads to recurrent infections, and an aggressive form of skin cancer. Most children with EB do not live past their 20's. Previously, there was no treatment and it was considered incurable. Wagner and colleagues published results in the New England Journal of Medicine showing effective treatment of EB using donor adult stem cells. One of the interesting aspects of this treatment is that it documents that bone marrow adult stem cells can travel to sites of injured skin, increasing production of collagen for these patients.
A 2010 article in the Journal of the American Medical Association provides a global perspective on adult stem cell transplants. Researchers looked at how many adult stem cell transplants were taking place in various parts of the world. This particular study looked only at hematopoietic stem cell transplants, i.e., transplants of blood-forming cells, obtained from bone marrow, peripheral blood, and umbilical cord blood; and did not survey uses of other adult stem cell types, such as mesenchymal, adipose-derived, or nasal adult stem cells. The published report found that in 2006, a total of 50,417 transplants were performed worldwide using these adult stem cells. Of that total, 57% used the patient's own adult stem cells, and 43% used donor adult stem cells. Almost half (48%) took place in Europe, followed by the Americas (36%), Asia (14%), and the Eastern Mediterranean and Africa (2%). They note that adult stem cell transplants have become "the standard of care for many patients" with blood disorders and malignancies, though they are starting to be used for other conditions including autoimmune disorders and heart disease. They also note that their study "demonstrates that it is an accepted therapy worldwide".
I am aware that some have criticized HB 171 and similar legislation, claiming that it would preclude stem cell research, or specifically embryonic stem cell research, or even that it would prohibit commonly used animal tests for pluripotent stem cells. Nothing could be further from the truth. The technique used involves injection of stem cells into immunocompromised mice; pluripotent stem cells form a a tumor (called a teratoma) within the mouse, potential data for their ability to form different tissue types. This test is done by injecting the cells into born mice, not mouse embryos.
It has also been hypothesized that patients who might receive injections of stem cells from their clones created and destroyed outside of the state of Ohio would be at risk of arrest upon entering the state of Ohio if HB 171 passes. This interpretation is based on a na�ve or willful misreading of the bill. Cells incorporated into a patient's body would not be covered by the bill, just as a patient who eats a hamburger in the U.K. would not be arrested at the state line for transporting hazardous meat that might contain mad cow disease, or who eats sprouts in Germany would not be arrested for potential transport of hazardous microbes.
Internationally, most countries have moved to ban all human cloning, including countries such as France (7 years in jail), Germany (5 years in jail), Canada (5 years in jail), and in March 2005 even the United Nations passed a declaration against all human cloning.
HB 171 only bans production of cloned human embryos and production of human-animal hybrids. It does not address embryonic stem cell research, nor any stem cell research. No stem cell research is prohibited by this bill, whether embryonic, iPS, adult, cord blood stem cells. HB 171 does not restrict any vital or viable medical research. Cloning and nuclear transfer techniques for production of DNA, other molecules, cells other than human embryos, tissues, organs, plants, and animals are all allowed.
There are no valid or compelling grounds�"ethical, scientific, or medical�"to allow SCNT cloning of human embryos for any purpose, nor for production of animal-human hybrids. A comprehensive ban is necessary, and HB 171 would accomplish that purpose without limiting any valid medical research. I encourage you to please do all that you can to pass this bill.
Thank you for the opportunity to contribute to the debate on this important issue.