Programme details

Scientists of today are breathing life into one of the myths of the past, human regeneration.
At the root of this potential for regeneration are cells, known as stem cells.

Stem Cells

To understand what a stem cell is, and as to why we apply a certain definition to say that a given cell is a stem cell, we need to understand what the function of a stem cell is.

A stem cell is above all a cell. And one of the major functions of every cell is to divide and give rise to two twin daughter cells, which will each in turn give rise to two daughter cells.
As soon as the egg is formed by the fusion of an ovule and a sperm, it rushes to divide again and again... until the embryo resembles a little blackberry composed of eight stem cells which are highly potent : each of them could in theory give rise to a full embryo, a foetus and finally a baby. Then around the fourth day, the dividing stem cells begin to specialise. They give rise to two types of cell : in the centre, a small internal mass will eventually become the future foetus, and at the periphery, the cells that will go on to form the placenta...
The cells of the internal mass are called “embryonic stem cells”. If we take cells from the internal mass, we find that every one of them has the potential, on dividing, either to form cells identical to themselves which can be grown to large quantities in culture, or alternatively, to form muscle, cartilage, neurons, blood and other tissues.
As the embryo advances in its development to become first a foetus and then a baby, most stem cells gradually specialize and lose their ability to form a wide diversity of different types of cells.

Changing Fate of a Cell

Research with adult stem cells taken from animals learns that under experimental conditions, the plasticity of stem cells can be defined as as the capacity to change fate when taken from one tissue and put into another tissue.
For example : you take stem cells from the bone marrow, put them in regenerating muscle and they will form muscle cells.
The change of fate is strictly regulated by the environment. But extensive studies in animals are required before a treatment for humans can be developed.

Medical Treatment by Stem Cells

There is already an example of medical treatment by stem cells, which has been used for ten years : patients suffering from leukaemia, a cancer of the white blood cells, can today be treated by the transplantation of blood stem cells obtained from the placenta. This is now simple and routine.

In Utero Transplantation

This program involves in utero transplantation where we will transplant stem cells directly into the fœtus while it's still in the womb. This procedure will then allow us to treat genetic disorders diagnosed early in gestation before the immune system is developed and before there is a chance to eject the tissue.
35 transplantations of this type have been attempted, but Rhodri Jones believes that we should wait for several years before concluding whether they have been entirely successful.

Gene Therapy

Researchers are looking at the possibility of transforming the stem cell before its implantation. This would allow use of a technique known as "gene therapy."
The use of gene therapy with stem cells could one day make it possible to cure certain genetic diseases, even before they become evident, very early in the development of the foetus or child.

Transplantation of Dopamine Producing Cells

The idea is to cure patients suffering from Parkinson’s disease. Parkinson’s disease is a rather selective destruction of a certain type of nerve cells in the brain, those that produce dopamine. These patients cannot control their movements properly because dopamine is essential for the transmission of information between nerves.

Stem Cells On the Market?

Some scientists are already preparing to change gear. They are taking an even more radical and ambitious path, by turning laboratories into “small companies” which are preparing stem cells like pharmaceuticals but for a hypothetical market.

Therapeutic Cloning

A major problem in stem cell therapy is the incompatibility between grafts and the patient which leads to rejection. Some scientists hope to overcome this problem using a technique called “therapeutic cloning” - a technique which has the potential to produce tissues and organs that are 100% compatible with the patient due to collecting embryonic stem cells from the fusion of a patient’s cell with a donor’s ovum.

Conclusion

Some of these techniques raise ethical questions : to what extent do we have the right to use embryos, and even create embryos, with the aim of healing the sick?
We need to find a way to reconcile the freedom to do research, and our desire to benefit from medical advances, with respect for fundamental ethical principles.