I wanted to pass along information on human stem cells that I have found helpful from several sources, including Dr. Francis Collins' 2006 book entitled 'The Language of God'. Dr. Collins, you may remember was the head of the Human Genome Project that was the first group able to sequence the human genome. He also identifies himself as a Christian, and his book is on evidence for belief in God from a scientist's perspective. The book is interesting for a number of reasons. But he also has a good section on the stem cell debate that I found helpful, and I wanted to pass it along, in hopes that it helps your understanding of the issue better.
Stem cells are found in all multi-celled organisms. Although all human cells have the entire DNA instruction book in them, there is something special and unique about stem cells. A stem cell is one that carries within the potential to develop into several types of cells. As an example, the bone morrow's stem cells can turn into a red or white blood cell, a bone cell, and even under the right environment, it can turn into a heart muscle cell.
First, there are two types of stem cells: embryonic stem cells and adult stem cells. The adult stem cell's importance is that they replenish and maintain a normal turnover of blood cells, skin and intestinal tissues. While embryonic stem cell potential remains untested, adult stem cell treatments have been used for many years to treat successfully leukemia and related bone/blood cancers through bone marrow transplants. The use of adult stem cells in research and therapy is not controversial when compared to embryonic stem cell research, because the production of adult stem cells does not require the destruction of an embryo.
So why are scientists so interested in using embryonic stem cells for their research? The embryonic stem cells are taken when there are between 50 to 150 cells after conception, which is very early in the embryo's development of between 4 to 5 days old. At this stage the embryonic stem cells are phenomenally flexible. They can develop into each of the more than 200 cell types of the adult body when given the right kind of stimulation for a specific cell type. But when the stem cells are taken, the embryo is killed. Let me leave this moral and ethical question on the side for now. If we can develop effective use of the stem cells, what can the research really do? And how can stem cells help out? If a friend of yours has Parkinson's Disease, they have the disease because neurons of a particular part of the brain have died prematurely. If you have a family member that is on a donor list for a liver, kidney, or even a heart transplant, it is because those organs are damaged and cannot repair themselves. I hope you see the almost fantastical hope that stem cell research can provide: instead of requiring transplants, regenerating a person's damaged organ is the promise of stem cells. The hope is that a person with Parkinson's Disease, can have the damaged brained cells repaired, regenerated, and brought back to life. Stem Cells could be the fountain of youth for any damaged organ. This is what is exciting so many people in the stem cell research field.
But what about the Embryonic Stem Cell debate, and the moral and ethical issues I raised earlier? If you take an embryo's stem cells, you destroy the embryo, and ends its life. Should we still go forward with embryonic stem cell research? Before you get all twisted up on this issue, it looks like scientific advances have already outpaced the issue. You may have seen an important news story last November. But let me bring it to your attention again. Researchers have turned skin cells into stem cells, with the same ability to develop into any of the 200 human cell types. The discovery is breathtaking:
Stem Cell Breakthrough Is Like 'Turning Lead Into Gold'
In an unprecedented feat of biological alchemy, researchers have turned human skin cells into stem cells that hold the same medical promise as controversial embryonic stem cells.
Two teams of researchers -- one led by Kyoto University's Shinya Yamanaka, the other by the University of Wisconsin's Junying Yu -- used a virus to add four new genes to skin cells. Thus transformed, the reprogrammed cells became capable of changing into nearly any cell type in the human body. Embryonic stem cells also have this ability, and may someday be used to cure degenerative diseases, grow new organs and even replace limbs…
So will this mean an end to the Stem Cell debate? Don't count on it. There is too much money already invested, and frankly some groups are more interested in the research and money involved to ignore the possibilities of Embryonic Stem Cell research. So keep an eye out for more news stories on this topic. I hope the resources I have summarized have given you a better handle of the subject.
Sources Used: Dr. Francis Collins, 'The Language of God'; Wikipedia, Stem Cells, Adult Stem Cells, Embryonic Stem Cells; News article from Wired Magazine (citation shown above.)