Embryonic stem cell research is indeed controversial, with some objecting to its implementation solely on moral grounds, while others are touting these cells as a miracle “cure-all.” President Bush has prohibited the federal funding of embryonic stem cell lines that were created after Aug. 9, 2001, and has come under intense criticism for this “ban.” Without taking a moral approach to this issue, are embryonic stem cells really the panacea for innumerable human illnesses?
- Angela Cesere
Stem cells can be divided into two categories: embryonic and adult. Embryonic stem cells are those obtained from the blastocyst of a developing fetus. As a result, the fetus is no longer viable. Adult stem cells, found throughout the entire human body, can be obtained without any harm to the donor. The goal of researchers is to use stem cells to form other bodily tissues. Adult stem cells are multipotent; for instance, a stem cell from the brain can develop into other types of brain tissue. On the other hand, embryonic stem cells are pluripotent, meaning they can form any cell within the human body. Sounds pretty good! But, this is a double-edged sword, as it becomes difficult to control the type of cell proliferation. Recently, embryonic stem cells were injected into the brain of a Parkinson’s patient. Instead of forming dopamine-secreting brain cells, the implanted cells formed hair, teeth, nails and bone, killing the patient. Also, due to this uncontrolled growth, embryonic stem cells are likely to cause tumors. Adult stem cells cause neither of these problems. They are capable of only forming into the target tissue required and are non-tumorigenic. Additionally, embryonic stem cells pose the risk of tissue rejection, unlike adult stem cells coming from the patient’s own body. To overcome tissue rejection it would be necessary for a patient to take immunosuppressive drugs.
As of October 2004, adult stem cells have been successfully used to treat 58 different illnesses in both rats and humans, whereas embryonic stem cells have presently resulted in no successful treatments. In order to determine which type of stem cells are more beneficial, researchers performed a series of comparison studies. Rats with Parkinson’s received injections of either adult or embryonic stem cells. In 80 percent of the rats receiving adult stem cells, neural regeneration occurred. However, only 50 percent of those receiving embryonic stem cells recovered, while 20 percent died from brain tumors. When adult stem cells were injected into the spinal cord of 18-year-old Melissa Holley, a paraplegic patient with a severed spinal cord, she regained movement of her toes and bladder control. When rats with severed spinal cords received embryonic stem cells, no recovery occurred. Also, scientists were able to reverse Type I diabetes in rats through the use of adult stem cells. Diabetic mice implanted with embryonic stem cells died, because these cells secreted only 1/50th the amount of insulin.
To set the record straight, Bush has been the first president to allot federal funds for stem cell research. Bush has put no restrictions on the use of adult stem cells and federal funding is allowed for cells that were derived “with the informed consent of the donors, from excess embryos created solely for reproductive purposes and without any financial inducements to the donors.” Federal funds are not provided “for the derivation or use of stem cell lines derived from newly destroyed embryos, the creation of any human embryos for research purposes or the cloning of human embryos for any purpose.” Notwithstanding, there is a current surplus of embryos that were destroyed prior to the initiation of this “ban” in 2001, which can be federally funded to develop an embryonic stem cell line. Also, it is perfectly legal to privately fund any form of stem cell research.
I am in no way trying to imply that the use of embryonic stem cells is fruitless, nor am I injecting any moral opinion regarding this issue. But the facts demonstrate that adult stem cell research has proved to be more successful at present and Bush’s “ban” may not be that restrictive after all.
Shuster can be reached at dshuster@umich.edu.