Adult Stem Cells (ASCs)

April 2010
Written by Erica Brown and Stacey Herzer

Adult stem cells are any stem cells found in the body after birth, and they have been found in various tissues such as the blood, skin, heart and brain. Scientists aren’t sure whether these stem cells actually originate in these tissues or if they’ve circulated into the tissue from the blood forming (hematopoietic) system.

Adult stem cells have less potential than ESCs because they typically can only regenerate a small number of cell types within a specific tissue, organ or physiological system. Due to this limitation, they’re called multipotent stem cells.

  • A good example of the adult stem cell is the well-studied blood-forming (hematopoietic) stem cell. These stem cells have already been differentiated to the point that they are part of the blood system and thus are limited to developing into red blood cells, platelets and white blood cells (immune cells). They are no longer described as pluripotent because they do not retain the ability to develop into any cell type– such as a brain or skin cell.
  • You may be surprised to learn that stem cell transplants to treat disease have been achieved successfully in humans for decades. Bone marrow transplants take hematopoietic stem cells from a healthy individual and inject them into a diseased person’s bone marrow to restore his or her ability to make health blood and immune cells. These hematopoietic stem cells are the basis for why bone marrow transplants work in helping to treat blood diseases like aplastic anemia, leukemia, lymphoma and some inherited blood conditions (2).

Adult stem cells may be more stable than the ‘wild card’ embryonic stem cells and may more easily develop towards a certain tissue type. A further benefit of using adult stem cells in research is that they do not raise as many ethical concerns as ESCs do. However, adult stem cells are only found in small numbers in the body and they’re more difficult to isolate, grow and use than ESCs are (1,3). More research is needed into adult stem cells to better understand their range of abilities.

If you are interested in more information on stem cells, please see the following:

References:

  1. National Institute of Health Stem Cell Information http://stemcells.nih.gov/
  2. Nussbaum RL et al. Thompson and Thompson Genetics in Medicine. 6th ed. 2004. Saunders.
  3. Lanza R, Rosenthal N. The Stem Cell Challenge. Scientific American 290(6). Jun2004.