Implications of Cloning Legislation on Potential Stem Cell-Based Therapies
Bert Vogelstein, M.D.
Biological and Biomedical Applications of Stem Cell Research Committee
National Research Council and Institute of Medicine
Professor of Oncology and Pathology
Johns Hopkins Oncology Center and the Howard Hughes Medical Institute
Concerning the Differences Between Cloning Human Beings and Nuclear Transplantation
Subcommittee on Labor, Health and Human Services, Education, and Related Agencies
Committee on Appropriations
December 4, 2001
Good morning, Mr. Chairman, and members of the Committee. My name is Bert Vogelstein, and I am a Professor of Oncology and Pathology at the John Hopkins Oncology Center and a Howard Hughes Medical Institute Investigator. I am here today as the chairman of a National Research Council and Institute of Medicine Committee on the Biological and Biomedical Applications of Stem Cell Research that recently released the report Stem Cells and the Future of Regenerative Medicine.
My goal today is to clarify some of the confusion surrounding two very different medical endeavors; the first is regenerative medicine, and the second is the cloning of a human being. Regenerative medicine, which as a field is in its infancy, involves growing cells and tissues for implantation in people with diseases or injuries to their organs, for example diabetes, Parkinson’s disease, heart disease, and spinal chord injury. The most promising avenue of regenerative medicine is the use of embryonic stem cells for eveloping tissues of many different types for transplantation into patients with these diseases or injuries.
A substantial obstacle to the success of transplantation of any cells, including stem cells and their derivatives, is the immune reaction of a patient’s body to cells that it perceives as foreign. Our report recommended that multiple approaches to reducing this problem be explored, including ways to manipulate the genetic makeup of the stem cell tissue to make it less likely to provoke an immune reaction, the creation of a large bank of diverse stem cell lines, and the development of embryonic stem cells using a technique known as somatic cell nuclear transfer. This involves taking the DNA from a cell of a patient in need of a transplant, inserting it into an egg cell that has had its nucleus removed, and triggering cell division. The resulting stem cells and tissue that can be obtained from this procedure would be genetically identical to the patient’s cells, and would in theory not be rejected by the patient’s immune system when transplanted into him or her.
This procedure for producing embryonic stem cells that are genetically identical to the donor’s tissue should not be confused with human cloning, which has the goal of creating a human being. In that endeavor, the DNA from the cell of an individual would be inserted into an egg cell that has had its nucleus removed, and that embryo would be implanted into a woman’s uterus so that it would grow into a child who is genetically identical to the individual whose DNA was inserted into the egg.
Unfortunately, the notion that genetically identical stem cells are the same as a genetically identical human being has obfuscated the important potential of developing transplant therapies with lower probabilities for rejection, and greater chance of helping improve the health of many sorts of patients.
There has been much confusion surrounding the terminology common to the causes of both regenerative medicine and those who wish to clone human beings. Because the term "therapeutic cloning" has been used by different sources to mean both the cloning of human beings and the production of embryonic stem cells genetically identical to their donor, it has become effectively useless. And because the term "somatic cell nuclear transfer" smells of scientific jargon, I propose the use of the term "nuclear transplantation" be entered into the debate over cloning legislation.
I urge lawmakers to deeply consider the differences between nuclear transplantation and human cloning, and to consider the enormous impact on clinical research, and indeed patients’ lives, if a ban on nuclear transplantation were to be enacted. President Bush’s announcement last August to allow federal funding for research on existing embryonic stem cell lines was a great step in the direction toward realizing the promise of stem cells in regenerative medicine. To ban nuclear transplantation would be a step backwards in this effort.
Our committee is respectful of the wide array of social, political, legal, ethical, and economic issues that must be considered in policy-making in a democracy, and we have been impressed by the commitment of all parties in this debate to life and health, regardless of the different conclusions they draw. It should be recognized that a large number of citizens oppose human cloning at the same time they support embryonic stem cell research and regenerative medicine. We hope our report, by clarifying what is known about stem cells and how best to realize their potential, will be a useful contribution to the discussion of this important issue.
Thank you for this opportunity to testify. I would like my statement to be put into the record, and I will be happy to answer any questions the Committee might have.