FAQs about Stem Cell Research

What is a stem cell?

They are in a sense, the cells from which all else “stems”. Bioethicist Alexander Capron of the World Health Organization described a stem cell as, “the foundation of organisms, the stalk from which everything buds and branches.” Stem cells may be either embryonic or adult (somatic). As a fertilized egg divides, the multiplying embryonic stem cells differentiate into or become all of the diverse tissues of the body, such as lungs, liver, brain, hair, heart.

What can stem cells do?

Stem cells have the potential to:
• Replace cell tissue that has been damaged or destroyed by illness,
• Replicate themselves over and over for a very long time,
• Help scientists understand the origin of human biological development
• Help scientists understand healthy & diseased cells in hope of creating treatments & cures for many diseases.

The National Institutes for Health (NIH) notes that stem cells “have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells for as long as the person or animal is still alive. When a stem cell divides, each ‘daughter’ cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell. A more detailed primer on stem cells can be found at http://stemcells.nih.gov/info/basics.”

What role do stem cells play in human biology?

Stem cells regenerate lost or damaged cells. For example, when a person gives or loses blood, stem cells will replenish the supply. If the skin is damaged, it generates new skin cells as it heals. Since stem cells have the ability to generate new tissue specific cells, this area of medicine is often called “regenerative medicine”.

All animals, including humans, start from one cell, which results from fertilization of an egg by a sperm. The resulting one cell contains all of the animal's genetic material or DNA and is capable of developing into a complete organism. As the cell divides, the resulting cells or daughter cells, will still contain all of the DNA, while at the same time becoming specialized, and more restricted in their ability to become all types of organs and tissues.

Are stem cells currently used to treat disease?

Yes, adult or somatic stem cells have been used for some time to treat disease. For example, blood stem cells created in the bone-marrow are used in “bone-marrow transplant" as a common therapy for various blood based diseases such as leukemia and aplastic anemia. Organ transplantation also uses stem cell technology.

What are the stages of human development?

The National Bioethics Advisory Commission (NBAC) provided a simple outline of human development:
1. the developing organism is a zygote during the first week after fertilization,
2. the organism is an embryo during the 2nd – 8th weeks of development
3. the organism is a fetus from the 9th week of development until the time of birth.

What is an embryonic stem cell?

Embryonic stem cells come from the “inner cell mass” of a group of cells called a blastocyst. The blastocyst is an early stage of development known as the “zygote” that occurs within the first 4-6 days after fertilization. Once the “inner cell mass” or embryonic stem cells are removed from the blastocyst, the cells may be kept alive in a petri dish under specific laboratory conditions. Such cells are pluri-potent meaning they may become any cell in the body.

What is an adult or somatic stem cell?

They are stem cells found in the tissue and organs of organisms that have the potential to become their tissue of origin. Essentially, adult or somatic stem cells are tissue specific stem cells that will have a specific occupation within the organism, for example, embryonic stem cells that differentiate or become heart stem cells will form heart tissue. Such cells have the ability to replenish or maintain tissues that have a limited life span, such as skin and intestines. For example, the human intestine sheds and replaces 100 billion cells daily by dividing stem cells that generate replacements for the short-lived cells. Thus, adult or somatic stem cells are “differentiated” or specifically assigned to the creation or replenishing of cells in specific tissues or organs.

What is differentiation?

Differentiation is the process in which a cell, such as a stem cell, specializes in the creation or replenishing of cells in specific tissues or organs in the body. The process occurs through the activation (“turning on”) or inactivation (“turning off”) of specific genes in the cells. The turning on/turning off process results in the development of cells that are assigned specific tasks such as creating the heart or replenishing the lining of the intestine.

What are the sources for embryonic stem cells?

1. Excess fertilized eggs from in-vitro ferilization clinics,
2. Using IVF procedures with donated oocytes and sperm to make blastocysts for research, or
3. Somatic Cell Nuclear Transfer (SCNT)

What is Assisted Reproductive Technology (ART)?

Assisted Reproductive Technology or ART includes all treatments or procedures that involve the laboratory handling of human eggs and sperm for the purpose of fertilizing an egg and helping a woman become pregnant.