UK Stem Cell Initiative [UKSCI]
Stem cells are the very early cells that can develop into almost all
other types of cell and tissue. They occur in the early (five-day) embryo
when it is a tiny ball of about 100 cells before it implants in the uterus
(embryonic stem cells or "ES cells"). They also occur in significant
numbers in some tissues in the developing fetus and in umbilical cord
blood at birth. They can also be found in some adult tissue, e.g. bone
marrow, but they can be difficult to isolate, being present in very small
Because of their ability to differentiate into so many different cells
and tissues, stem cells hold out exciting prospects for the development
of new cell-based therapies. They are already used for some treatments
of cancers (bone marrow stem cells) and in early clinical trials in Parkinson's
disease (foetal stem cells). The hope is that tissues derived from stem
cells will provide a limitless supply of material to treat currently-incurable
diseases and injuries.
The Government wishes to see research using all sources of stem cells.
Currently, it is too early to know where the most useful findings will
Most ES cell research uses cells derived from in vitro fertilisation
(IVF) embryos donated by couples for research when they are not needed
for infertility treatment. Another possible source of ES cells may be
from embryos created for research either using egg and sperm or using
techniques such as cell nuclear replacement (CNR), or therapeutic cloning.
The use of cloning techniques may prove to be a very powerful tool in
developing treatments that avoid rejection by the immune system of the
UK law on embryo research has evolved over 20 years through public and
parliamentary debate. The Human Fertilisation and Embryology Authority,
established in 1991, subjects all embryo research in both the private
and public sector to a robust system of case by case review before any
license to permit research is issued. Our legislation contains other important
protections for the embryo. Research is only allowed for the limited purposes
set out in the legislation and no research is allowed on embryos over
14 days old.