Are fetal stem cells and embryonic stem cells the same?
There is much confusion in the media as well as the scientific community as to what defines a “fetal stem cell”.
Fetal stem cells are not the same as Embryonic or Adult stem cells. Embryonic stem cells are harvested from a 5-day-old embryo after artificial fertilization. Adult stem cells are harvested from adults, and given back to the adult. Fetal Stem Cells are harvested from a 7 to 12 week-old fetus. However, some of the scientific community still considers stem cells harvested from a fetus as “Adult”, creating more confusion. But “adult” and “fetal” are very different.
Many people confuse “Embryonic” stem cells with “Fetal” stem cells, but they aren’t the same type of stem cell. To make matters more confusing, many asian and middle-eastern cultures do not have a vocabulary word for “fetal” which means they define both Embryonic and Fetal as “Embryonic”.
Embryonic stem cells can also be quite dangerous as they as known to cause tumors. However, fetal stem cells have had no recorded cases of anyone getting a tumor from fetal stem cell injections.
What is an autologous or adult stem cell?
Adult stem cells are also called “autologous” stem cells. Fetal stem cells are not autologous stem cells. At EmCell, they use different types of stem cells harvested from various growth zones of 7-12 weeks old legally aborted and properly screened fetuses.
These fetal stem cells can differentiate into the wide range of cell types within the certain germ layer – ectodermal, endodermal or mesodermal. Moreover, stem cells EmCell uses have higher proliferative potential compared to other types of stem cells (adult stem cells, cord blood stem cells etc.)
At the same time, they have already undergone specialization in the germ layers, lost their capacity for uncontrolled growth and “know for sure” what cell or tissue type they should differentiate into. Fetal stem cells (7-12 weeks old) are different from embryonic stem cells (4–5 days post fertilization) which are capable of uncontrolled growth that can result in teratomas. Using true fetal stem cells, not embryonic stem cells, EmCell has no cases or history of post-treatment tumor development in their patients.
The adult stem cell is thought to be an undifferentiated cell, found among differentiated cells in a tissue or organ. These cells can renew itself and can differentiate to yield major specialized cell types within a tissue or organ in which these cells are placed. The primary roles of adult stem cells in an organism are to maintain and repair the tissue and organ in which they are found. Adult stem cells can be identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium and testis.
Typically, there is a very small number of stem cells in each tissue and organ and if these cells are removed from the body their capacity to divide becomes limited, thus it is difficult to make a generation of large quantity of stem cells. Besides, adult stem cells express histocompatibility antigens which require HLA-based donor-recipient compatibility, including individual antigens, or immunosuppression.
The fetal stem cells are the pluripotent stem cells, which are often termed ‘true’ stem cells because they have a potential to differentiate into almost any cell in the body. It means that under the right circumstances, stem cells which are isolated from fetus can produce almost all types of the cells in the body. Fetal stem cells provide a chance to obtain a renewable source of healthy cells and tissues to treat a wide range of diseases.
What about rejection or DNA matching?
Rejection is also not an issue with fetal stem cells as HLA expression in them is either absent or minimal, while adult and cord blood stem cells do express histocompatibility antigens, which requires donor-recipient HLA matching or immunosuppression. The potential of autologous stem cells and fetal stem cells are very different, the possibility of clinical changes in autologous (adult) stem cells is low, thus not effective in degenerative conditions.