Adult Stem Cell Breakthroughs Continue Embryonic Stem Cells Disappoint
Not an embryo and without the possibility of ever becoming one, “embryo like” cells were created by taking a simple biopsy of human stem cells from skin. The respected journals, Cell and Science published the breakthrough discovery, made concurrently by two separate Japanese and U.S. Research teams, on November 20, 2007. The efficiency of the method cannot be denied. Eliminating the risk of tissue rejection, the cells can be taken directly from the patient; just one biopsy can produce 20 cell line. But now, with “breakthroughs” in stem cell research reported regularly, just what makes this particular breakthrough different? Could it be the discovery that ends the stem cell debate?
To put it simply, stem cell are immature cells that make all other cells in the body. Some stem cells are limited to creating only one type of cell, others can make many types. Thus, some stem cells are more versatile than others.
When two scientists isolated a teratoma from a mouse in the 1950's, it was the catalyst for embryonic stem cell research. Scientists aptly named it a teratomas, or “monster”, because the tumor that is a teratoma is made up of various types of cells ranging from nails to teeth to eye cells. This array of cell types had properties very similar to embryonic stem cells. This observation prompted scientists to begin investigating embryonic stem cells.
Bone marrow transplants had been used to treat leukemia patients before the term “stem cells” had become popular. Whenever a patient receives a bone marrow transplant from a donor, they are really receiving a type of stem cell therapy. Only a very specific cell treatments could be performed by scientists using bone marrow stem cells at this point. The theory at the time was that these stem cells were not very versatile. But the attitude changed over time as more research was performed. With the potential of being coaxed into becoming a wide variety of cells, bone marrow stem cells proved themselves to be quite versatile. In order to cure or alleviate a number of conditions and diseases, scientists have since turned to a variety of adult stem cells that are found through out the human body. A complete list can be found at stemcellresearch.org.
Fetal tissue provided another breakthrough in stem cells. Stem cells were derived not from fetuses, but from menstrual blood, amniotic fluid, placental tissue, and umbilical cord blood. With the potential to transform into more types of cells, these cells are more versatile than bone marrow stem cells. An exact match is also not required between the donor and the recipient.
For the purpose of later use, umbilical cord blood can be “banked” for future therapy. Cord blood can also be donated for use by other patients. The National Cord Blood Program is just one group that allows parents to do this. Patient success stories can be found at nationalcordbloodprogram.org.
If these are ADULT stem cells, then what are EMBRYONIC stem cells? An embryo which is eight days old, provides these cells. In the process, the embryo dies once the cells are removed. These are considered to be the most versatile stem cells since they have the potential to create almost all the cells of the human body. Meaning versatile, the term “pluripotent” has been used to define these cells. Since we know that embryonic stem cells have the potential to transform into so many different types of cells, some scientists believe that time, money, and other resources should be directed at embryonic stem cells (ESC's).
Ironically, science has not been on the side of these scientists who support embryonic stem cell research. The much hyped embryonic stem cells have been championed as a cure all, but have failed in every respect. However, adult stem cells have been behind success after success. Via bone marrow transplants, adult stem cells have been saving the lives of patients for years. In contrast, scientists still cannot control the growth rate of embryonic stem cells. Taratomas, grotesque tumors that are composed of various cells found throughout the body, are typically formed by ESC's; a life-threatening characteristic that shouldn't surprise anyone.
The debate between adult and embryonic stem cell s has raged on for years. Some considered the embryo a very vulnerable life that has the right to be protected from experimentation, while others, wanted unrestricted research privileges to explore this option for potential medical use. Both sides argued that their side was working for the good of mankind.
The debate, has perhaps shifted in recent weeks. The science of converting basic skin cells into pluripotent “embryonic like” stem cells has added a new twist to the ethical debate.
Without taking any embryos to obtain these cells, scientists have isolated human stem cells that are as versatile as embryonic stem cells. The cells behave exactly like ESC's in the lab, but more tests are still needed to determine if they will function as such in the human body.
Concerns do exist with the procedure. The stem cell are made using a virus that carries the correct code into the cells to coax them into transformation. It is unknown if the virus is harmful in humans or not. But research to solve this problem is well underway, and the expectation is that the cells will function properly while being completely safe.
Does this method remain ethical? The answer is believed to be a strong yes.
“Reprogramming of human somatic cells to pluripotency is an enormously significant achievement, one that boosters of medical progress and defenders of human dignity can celebrate without qualification,” said Leon Kass, former head of the President’s Council on Bioethics, while attending the National Review Online symposium.
Since the destruction of embryos is not necessary for this research, nor the creation, the method can be celebrated.
It should be understood that the research could not have been accomplished without prior knowledge of embryonic stem cells. Both scientists who published the discovery, Yamanaka from Japan and Thompson from the U.S, agree with this. In fact, one of the first scientists to remove a stem cell from a human embryo was Thompson. However it should be noted that both scientists had more than just economic reservations about using embryos in their research, contrary to what some in the scientific community are saying.
“If human embryonic stem cell research does not make you at least a little bit uncomfortable, you have not thought about it enough…I thought long and hard about whether I would do it,” said Thompson.
“When I saw the embryos, I suddenly realized there was such a small difference between it and my daughters…I thought, we can’t keep destroying embryos for our research. There must be another way,” added Yamanaka.
Some big players have spoken up, with most people agreeing that this changes the political and scientific culture of the stem cell debate.
“If their method is as good as the oocyte (the cell that forms a human egg)…we will be no longer in need of the oocytes, and the whole field is going to completely change. People working on ethics will have to find something new to worry about,” stated Jose Cibelli, research scientist whose successful primate cloning was overshadowed by the skin cell announcement states.
Even Ian Wilmut, the scientist famous for creating Dolly the Sheep decided to abandon cloning and work with reprogramming cells instead. As the Britain’s Telegraph reports, “The scientist who created Dolly the sheep, a breakthrough that provoked headlines around the world a decade ago, is to abandon the cloning technique he pioneered to create her… ‘I decided a few weeks ago not to pursue nuclear transfer,’ Prof Wilmut said.”
Pragmatically, this seems to be significantly more efficient than cloning embryos to remove stem cells, and several of the participants of National Review Online Symposium agree that this removes the ethical concerns from researching pluripotent cells. But this is easier said than done.
Wesley Smith, bioethicist, ESC critic and Discovery Institute fellow, points out that the new research does not end the stem cell debate so easily.
“If anyone thought that the pro human cloners would fold up their tents and steal away after the news was released that patient-specific, pluripotent stem cells had been derived from normal skin cells, they just don’t understand how fervently some scientists and their camp followers want to clone human life—and how hopeful some are that the stem cell issue can be the vehicle that wins the culture war.”
Scientists with a utilitarian worldview are involved, some with entire careers based on the science. Embryonic stem cell research is not going to be readily abandoned by a scientist whose worldview is dictated by “whatever is for the greater good” and has built his entire career and reputation around ESC.