Stem Cells: ASCs vs. ESCs
by Mark Silva
The subject of stem cell research has caused some to leap for joy, some to shake their head in disgust, while many others are confused about the whole controversy. Stem cells have the potential to develop into many if not all types of different cells in the human body. Learning how stem cells develop into specific cell types can help in the study of very serious medical conditions like birth defects and cancer. Further research might help replace diseased or destroyed cells or tissue, instead of relying on the short supply of available transplant organs.
There are two types of stem cells, adult stem cells (ASCs) and embryonic stem cells (ESCs). ASCs, taken from bone marrow, have been used for over 40 years in treating people with blood disorders. They can also be found in many other parts of the body. ESCs, on the other hand, taken from aborted babies or leftover fertilized eggs from in vitro fertilization clinics, have been getting more interest lately since they have the potential to develop in all tissue types (US National Library of Medicine). Both ASC and ESC have their advantages and disadvantages.
Celebrities who are near and dear to those hoping for cures, like Christopher Reeves, Michael J. Fox and Ronald Reagan, have helped bring stem cell research to the forefront of the news and of the recent Presidential debates. These celebrities and those of the scientific community are anxious to find ways to alleviate the pain and suffering of those with diseases and catastrophic injuries. Being paralyzed for fifteen years, I am also anxious to explore the benefits of stem cell research. However, I lay my hopes in furthering ASC research where human life would not be destroyed, unlike ESC research.
Finding an abundant source of stem cells to study will help further advance stem cell research. ESC research is limited to the ESCs harvested from excess frozen embryos in fertility clinics and aborted babies. Informed consent is needed from the donors of embryos and aborted babies, which further restricts the amount of ESCs available for research. Even though ESCs can be regenerated into millions of identical stem cells, they are reproduced from the initial thirty cells. This limits the variety of different stem cells that can be researched.
ASCs are limited to the vast variety of populations of the world. ASCs can be found in many different parts of the body, yet primarily are harvested from bone marrow, fatty tissue, umbilical cord blood and placentas. Bone marrow was the earliest and best-known source of stem cells. The American Red Cross has been keeping a large database of donors who would be excellent matches for those who need therapeutic stem treatments.
A recent abundant source of ASCs has been found in human fatty tissue. Since their discovery in 2001, researchers have found that stem cells in fatty tissue can be transformed into nerve, bone, muscle, and blood tissue. More than 300,000 liposuction procedures are performed in the
Another significant source of stem cells is found in the blood of umbilical cords and placentas. This type of ASC is most desirable since it is the youngest and has the least amount of damage. Although there are a number of blood banks storing blood from umbilical cords, it has been found that ten times as many stem cells can be derived from placentas (National Marrow Donor Program). The largely unused source of placental stem cells has the ability to develop in a wider variety than umbilical and bone marrow stem cells.
Conversely, the possibilities of ESC seem to be great. It is from these cells that the human body is formed. Two hundred and twenty different types of cells and tissue are found in the human body. As of yet, there is no substantial claim that ESC research is superior to the ASC research. In fact, ESCs have not yet been used in human therapeutic trials. Moreover, human ESCs spontaneously develop genetic “abnormalities” in culture. There is no evidence that ESCs can be consistently driven to uniformly generate only the cell type that is needed, which might lead into developing muscle or bone tissue in the treated damaged spinal cord (Vancanti, 2004, November). Maybe in time, clear evidence of the benefits of ESC research will be found. In the meantime, ASC provides ample hope.
ASC research has been showing increasing promises in help healing the human body. The research has been going on for over forty years. ASCs show immune tolerance. ASCs have treated brain, ovarian, testicular and breast cancers. They have been beneficial in the treatment of various forms of leukemia. ASCs have helped in alleviating arthritis while restoring bone and cartilage. Over fifty different diseases have been treated with ASCs, which were testified before the US Congress by Richard M. Doerflinger (Doerflinger, R., 2003, March). ASC research continues to show greater promises of ESC research.
Along with the financial and academic costs of eradicating diseases in our lifetime, there are ethical and moral costs to consider in choosing stem cell sources. Though research has determined that stem cells have the ability to develop into a variety of specific organ cells, the use of ESCs destroys life. Our society supports the fact that life is precious and valuable in each and every stage. Since the embryo is the first stage of a human life, how can today’s society justify taking the life of the unborn by harvesting ESCs, in order to aid the living? How can the unborn speak up for their precious rights for themselves? They cannot. As benefactors of a civilized society, moral Americans should speak up for the rights of all, young, old and indigent. The ethical and moral costs of ESC use are far too high.
Scientists should continue to research different ways to help alleviate the suffering and dying. Stem cell research is one very important and promising route. ASC research does not destroy life, yet can save lives. ASCs can be harvested fro the patient’s own body, with very few side effects. The valued and abundant ASCs can be freely harvested from a variety of healthy donors. Medical researchers should not promote the ending of life of an embryo by continuing ESC research. The medical community should let the embryos survive, while continue helping the suffering by advancing of the successes made in ASC research.
Further stem cell research should be continued to find medical discoveries to prevent birth defects, serious diseases like diabetes and cancer, and catastrophic injuries. In particular, ASC research should have higher priority over ESC research, since ASCs have the potential to be as flexible as ESCs, have fewer complications than ESCs in treatment of patients, have a greater variety and abundant sources of stem cells, and have less moral and ethical costs than ESC research. No American is more anxious to find medical cures to catastrophic injuries and diseases than I am. The scientific community should place a higher value on life by pursuing further ASC research to help the suffering rather that ESC research. Every life is too sweet and precious and should not be taken lightly.
---Doerflinger, Richard. “The Testimony of Mr. Richard Doerflinger: Cloning: A Risk to Woman?” 27 Mar. 2003.
http://commerce.senate.gov/hearings/testimony.cfm?id=685&wit_id=1821 (5 Nov. 2004).
http://www.marrow.org/MEDICAL/ cord_blood_transplantation_basic.html (25 Oct. 2004).
Stem Cell Research Foundation. “What’s New.” Oct. 2004.
http://www.stemcellresearchfoundation.org/WhatsNew/October_2004.htm#1 (25 Oct. 2004).
US National Library of Medicine. “Stem Cell Research.” 17 Nov. 2003.
http://www.nlm.nih.gov/medlineplus/ency/article/007120.htm (18 Nov. 2004).
Vancanti
http://www.the-scientist.com/yr2004/nov/research3_041122.html (20 Nov. 2004).
posted by Greg @ 8:54 AM
0 comments
