Myths and Facts: Embryonic vs. Adult Stem Cells

I've been working on my previous response to The Alliance for Medical Research talking points on Embryonic Stem Cells. The new version can be printed on 2 pages, although I had to skip the references. Feel free to print and use, just be sure to send 'em to LifeEthics.org!

Regenerative Medicine Myths and Facts About Embryonic vs. Adult Stem Cells: Basic research vs. therapy that is applicable in patient treatments.

1. Myth – “Embryonic" means primitive or “early.”
Fact – Embryonic Stem Cells (ESCs) come from an embryo which is an organism in the embryonic stage of development.

2. Myth - The embryo is just a hollow ball of undifferentiated cells.
Fact - Embryos are complete organisms. The cells of an intact embryo are organized along an axis that is determined from the moment of fertilization. By the second or third division, the cells have committed to become the placenta or the body of the unborn child. ESCs are harvested from the second type of cells, and require the destruction of the embryo.

3. Myth - Adult stem cells (ASCs) have only been successful in treating diseases of the blood and bone marrow.
Fact - Over 70 diseases are being treated or are in early trials in human patients using adult stem cells. These include blood and bone marrow diseases (sickle cell anemia and other genetic blood diseases, leukemia, and lymphoma), bone marrow loss due to cancer therapy, autoimmune diseases (Rheumatoid Arthritis, Lupus and Multiple Sclerosis) and for corneal transplants grown from a patient’s own stem cells. Dr. Carlos Lima in Portugal reported improvement in patients with spinal cord injury. In the US, there are trials using ASCs to treat or cure genetic defects in metabolism and blood diseases, brain trauma in children (Dr. Baumgartner in Houston) and all of the above.

4. Myth - ESCs weren’t discovered until 1998, so scientists need more time and money to catch up with the 40 years of adult stem cell research.
Fact - James Thomson’s patent on all ESCs is being challenged on the grounds that his success in obtaining a human ESC line in 1998 was simply an outgrowth of over 25 years of research in labs all over the world.

5. Myth – Research on ESCs holds more promise than research in adult stem cells to discover the causes of disease, and to test drugs on human tissues.
Fact - Animal models and non-destructive human stem cell techniques are being used in all of these ways as well as in actual applications for therapy for human patients, without the ethical controversy.

6. Myth - ASCs offer less hope than ESCs because they are hard to find, are scarce, and can only become one type of cell.
Fact – ASCs are much easier to obtain in quantities large enough for research and therapy than ESCs. Most tissues have been found to contain stem cells or to be regenerated by stem cells from the bone marrow and other depositories. We are discovering stimulating and recruiting factors, as well as other conditions that can induce adult and umbilical cord cells to reprogram and multiply, both in the lab and in the body. Every day, the umbilical cord blood of thousands of babies is thrown away.
The research on guiding the development of all types of stem cells requires specific environments, nutrients and stimulating factors. Our knowledge and ability to obtain desired stem cell lines and the volume of cells needed for use in human patients is becoming more advanced and efficient in animal models and in human non-embryonic stem cells. Researchers have reported several ways to obtain “embryonic-like” or “pleuripotent” stem cells from a patient’s own adult stem cells and umbilical cord blood, without the need to create and destroy an embryo.

7. Myth - Embryonic stem cells are better for research because they can become any cell type of the human body.
Fact - ESC are proving hard to control, cause tumors, differentiate into cell lines other than the ones desired, and developing genetic mutations more often than ASCs as they divide. ESCs have only been used in animal models because they have proven difficult to control. Embryonic/fetal stem cells in animal research cause tumors 20 to 75% of experimental animals. The California Initiative for Regenerative Medicine released its strategic plan in early October, 2006, which states that no human therapies or trials in humans using ESCs can be expected for 10 to 15 years.

8. Myth - Embryonic stem cells will only come from fertilized eggs left over from in vitro fertilization or from Somatic Cell Nuclear Transfer (SCNT), which does not involve a sperm or fertilization.
Fact - All human embryonic stem cells require the destruction of a human embryo, whether that embryo began by in vitro fertilization, parthenogenesis, or SCNT.
Some researchers are currently making new embryos for the production of ESCs by in vitro fertilization in order to study specific diseases and certain characteristics. Others are attempting to make embryos by SCNT or cloning, which no one has been able to do in spite of thousands of human eggs from hundreds of women used in the attempt. All are inefficient and will require perpetual donation of endless numbers of oocytes that must be derived from thousands or millions of women, with the hazards of superovulation.

Definition of embryo from the International Society for Stem Cell Research Guidelines (Draft, Summer, 2006):
Embryo: The term “embryo” has been defined and used differently in different biological contexts. . . . However, the nomenclature has now been used generically by modern embryologists to also include the stage of first cleavage of the fertilized ovum onwards to nine weeks of gestation in the human and to term in the mouse. Two, four, and eight cell stages, the compacting morula, and the blastocyst are all more precise terms for pre-implantation embryos.