Scientists have reported that the incidence of leukemia and infections in elderly people may be due to the ageing stem cells.
Stem cells are undifferentiated cells that have the potential to regenerate itself and develop into all types of specialized cells types that may form various types of cells of the tissue from which it was taken.
Researchers working in the Stanford University School of Medicine have found that bone marrow stem cells slow down with age in their ability to produce new blood cells. This causes the lack of immunity in the elderly mice that may lead to infections. Also such slow down can also mean high incidence of leukemia due to cancer of the blood cells. This happens as the older blood forming cells use a gene that causes cancer. These aged stem cells continue functioning as before, only slow down considerably. This turn on the gene that causes cancer in the blood cells.
Another result of the study was that the aged stem cells even when are introduced in the younger mice, continue to behave as before, inculcating in the younger mice the same manifestations that were present in the older mice.
Reference: Proceedings of the National Academy of Sciences, June 2005