The Value of Therapeutic Cloning for Patients
- There is some confusion surrounding use of the word "cloning." BIO opposes cloning to create a new human being (reproductive cloning) because it is unsafe and unethical. However, it is important to distinguish between that and other appropriate and important uses of the technology such as cloning specific human cells, genes and other tissues that do not and cannot lead to a human being (therapeutic cloning). These techniques are integral to the production of breakthrough medicines, diagnostics and vaccines to treat many diseases. They could also produce replacement skin, cartilage and bone tissue for burn and accident victims, and result in ways to regenerate retinal and spinal cord tissue.
- The nation's top scientists from The National Academies of Science and National Institutes of Health, as well as numerous Nobel Laureates attest to the scientific value of this research. A February, 2002 report from the National Academies of Science concluded that while reproductive cloning is unsafe and should be banned, therapeutic cloning has sufficient scientific potential that it should be allowed to continue.
- Therapeutic cloning is supported by former Presidents Ford and Carter as well as former First Lady Nancy Reagan.
- Stem cell research will help scientists learn how to develop cells and tissue to cure disease. Over many years, scientists have demonstrated that they may learn how to induce these cells to differentiate into many different cell types. Accomplishing that would enable scientists to create new, healthy cells and tissue for transplantation to replace damaged or dead tissue.
- But one major problem with developing disease therapies with stem cells is the body's immune response system. When cells, including donated organs, tissues or blood, are transplanted or transfused, the recipient's body mounts a rejection response, attacking these cells as foreign. If a patient's own cells were the source of stem cells used to create therapeutic cells or tissues, it is believed that immunological rejection could be avoided since the cells and tissues would genetically match his own. Therapeutic cloning could allow an individual's own cells to be used to treat or cure that person's disease, without risk of introducing foreign cells that may be rejected. Thus, cloning is vital to realizing the potential of stem cell research and moving it from the lab into the doctor's office.
How Therapeutic Cloning Works:
- Therapeutic cloning is sometimes referred to as "somatic cell nuclear transfer" or "SCNT". SCNT involves removing the nucleus of an egg cell, replacing it with the material from the nucleus of a "somatic cell" (such as a skin cell) and stimulating this cell to begin dividing. This egg cell is never fertilized by sperm, and the genetic material within the cell is virtually identical to the genetic material extracted from the skin or other cell. Once the cells begins dividing, stem cells can be extracted from it 5-6 days later, just as they can be extracted from embryos created through in vitro fertilization. These stem cells - or the specialized cells derived from them - will be a genetic match to the patient. Therefore, the promise of SCNT is that the patient's body would accept these cells after transplantation.
- By using SCNT, scientists hope to understand how the protein factors in the egg cell cause these already specialized somatic cells to become stem cells. Once scientists learn how this cell "de-differentiation" occurs, they will no longer need to use egg cells.
- SCNT has nothing to do with sexual reproduction. It is a research technique to create cells that can be used to treat diseases such as Parkinson's Disease, diabetes, ALS, etc. The sole purpose of this technology is to address currently unmet medical needs.
Why Therapeutic Cloning is Valuable:
Because of SCNT, science could advance to a point where millions of people will have access to life saving therapies developed using their own DNA.
A Specific Example of How SCNT Could Help Patients in the Future:
Suppose a middle-aged man suffers a serious heart attack while hiking in a remote part of a National Park. By the time he reaches the hospital, only a third of his heart is still working, and it is unlikely he will be able to return to his formally active life. He provides scientists a small sample of skin cells. Technicians remove the genetic material from the cells and inject it into donated human eggs from which the chromosomes have been removed. These altered eggs will yield stem cells that are able to form heart muscle cells. Since they are a perfect genetic match for the patient, these cells can be transplanted into his heart without causing his immune system to reject them. They grow and replace the cells lost during the heart attack, returning him to health and strength.
Another important use of SCNT is to create new embryonic stem cells. These cells have been recognized in the scientific literature and by the NIH as having important biological properties. Specifically, they can be turned into any type of cell in the body. Therefore, they could provide the scientific basis for research leading to cures and treatments for disease. However, the cells currently available to researchers are insufficient because:
- They do not allow full investigation of the genetic causes of disease. For example, scientists need to create new cells that actually contain genetic diseases in order to study how these diseases affect the growth and development of other cells and tissue.
- They are not sufficiently racially or ethnically diverse. Certain diseases are more prevalent in people of particular races (such as sickle cell disease). By creating new stem cells from people of specific races, scientists could help unravel the causes of these diseases. An Institute of Medicine study from 2002 noted that the fewer cell lines that are available to researchers, the lower the genetic diversity they represent.
- Scientists need more cell lines to fulfill the promise of stem cell research.
Using SCNT, scientists can create new stem cells to meet these important health needs.