Adult stem cells are undifferentiated cells found throughout the body after embryonic development that divide to replenish dying cells and regenerate damaged tissues. Also known as somatic (from Greek Σωματικóς, of the body) stem cells, they can be found in children, as well as adults.

Research into adult stem cells has been fueled by their abilities to divide or self-renew indefinitely and generate all the cell types of the organ from which they originate — potentially regenerating the entire organ from a few cells. Unlike embryonic stem cells, the use of adult stem cells in research and therapy is not controversial because the production of adult stem cells does not require the creation or destruction of an embryo. Adult stem cells can be isolated from a tissue sample obtained from an adult. They have mainly been studied in humans and model organisms such as mice and rats.

Adult stem cell therapies

main: Stem cell treatments Due to the ability of adult stem cells to be cut out from the patient, their therapeutic potential is the focus of much research. Adult stem cells, similar to embryonic stem cells, have the ability to differentiate into more than one cell type, but unlike embryonic stem cells they are often restricted to certain lineages. The ability of a stem cell of one lineage to become another lineage is called transdifferentiation. These stem cells have also been known to cause some types of cancer Different types of adult stem cells are capable of transdifferentiation more than others, and for many there is no evidence of its occurrence. Consequently, adult stem therapies require a stem cell source of the specific lineage needed and harvesting and or culturing them up to the numbers required is a challenge.

Pluripotent stem cells can be found in a number of tissues including umbilical cord blood. Using genetic reprogramming, pluripotent stem cells equivalent to embryonic stem cells have been derived from human adult skin tissue. Other adult stem cells are lineage-restricted (multipotent) and are generally referred to by their tissue origin (mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, etc.).

A great deal of adult stem cell research has focused on clarifying their capacity to divide or self-renew indefinitely and their differentiation potential. In mice, pluripotent stem cells can be directly generated from adult fibroblast cultures.

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 as controversial as embryonic stem cells, because the production of adult stem cells does not require the destruction of an embryo. Consequently, more US government funding is being provided for adult stem cell research.