What Is the Difference Between Adult Stem Cells & Embryonic Stem Cells?

Stem cells are the object of intense biomedical research. Two types of stem cells, adult stem cells and embryonic stem cells, differ fundamentally in their origin. Their different origins give these cells distinctive biological properties as well as attract controversy.

Facts

• According to the National Institutes of Health, a cell must have two properties to be considered a stem cell. First, it must have a capacity for self-renewal or the ability to produce cells identical to itself. Second, it must have the capacity to produce the highly specialized, or differentiated, cells that form the tissues of the body.

Origins

• Adult stem cells, also known as somatic stem cells or tissue-specific cells, are taken from the tissues of a fully developed individual. These cells function in the body to repair or replace damaged tissues with new cells. Embryonic stem cells are cells removed from an early-stage embryo, the blastocyst. During development, these cells divide and grow into the whole organism.

Potency

• The definitive difference between adult stem cells and embryonic stem cells are their origins, but scientists working with both types of cells have observed that embryonic stem cells more readily differentiate into different tissue types. This capacity to become many kinds of cells is called potency. However, many researchers are working on environmental triggers to make adult stem cells as potent as embryonic stem cells.

Controversy

• Embryonic stem cells are a controversial line of research because their collection requires the destruction of an embryo. Many people throughout the world believe that the human embryo holds the rights of a born person and that this destruction constitutes a killing. Because adult stem cells can be derived from consenting adults, this work is rarely considered controversial.

Function

• Despite the large amount of controversy over the ethics of embryonic stem cell research, there is a major push throughout the scientific community to do research into both adult and embryonic stem cells. This is because stem cells have been able to treat and cure animal models of human disease, and there are high hopes that research from both of these avenues will be able to address conditions such as juvenile diabetes, spinal cord injury and multiple sclerosis.