An adult stem cell that may have the potential to grow into any other type of cell in the body has been found in the bone marrow of mice. This may offer the promise of treatment or cures for many human conditions, but without the ethical problems that surround the use of stem cells derived from embryos.
The discovery was made by a team led by Dr Neil Thiese of the New York University School of Medicine and Dr Diane Krause of the Yale University School of Medicine. They say that their research 'provides the strongest evidence yet that the adult body harbours stem cells that can be just as flexible as embryonic stem cells'.
The researchers took and purified stem cells from the bone marrow of male mice. Single cells were then selected and each implanted into one of 30 female mice which had been irradiated to destroy their own bone marrow. The Y chromosome, a marker for male cells, was used to trace the progeny of the stem cells in the female mice. After 11 months, five of the mice were still alive and the Y chromosome was, as expected, found in bone marrow and blood cells, but was also found to be present in other cells. These included cells in tissue from the lung, oesophagus, stomach and intestines.
The researchers say that the 'super' stem cell seems to have the potential to differentiate into cells from most, if not all, organs and tissues in the body. They also believe that the findings could apply to humans. But they say that this should not prevent work continuing on embryonic stem cells. Dr Krause said 'it's of great concern to me that our data not be used as an argument for discontinuing work on embryonic stem cells and fetal tissue'.