Stem Cells

What are stem cells?

Stem Cells are cells which can grow and change into many different types of cell. They can also repair organs in the body, by replicating themselves and replacing cells which are damaged or dying in that organ.

Our cells are forever dividing and replenishing themselves

Each new stem cell can become another type of cell with a different purpose, depending on the specialist need of the organ into which they are implanted – they could become a brain cell, a muscle cell, a red blood cell etc.

A stem cell can either renew itself by becoming another stem cell, or with some intervention, be encouraged to become a cell specific to a particular organ’s needs, to replenish itself as a cell suited to that organ. This means in the future we should be able to re-grow our own organs on demand, rather than rely on transplants which are prone to rejection by our own immune system.

Scientists learnt to create embryonic stem cells from mouse embryos 50 years ago, and from human embryos 20 years ago. As the latter is controversial, new methods of generating stem cells were sought. 10 years ago, scientists learnt how to re-program adult cells to become and behave like stem-cells. These are known as ‘induced pluripotent stem cells’.

Unlike other cells, stem cells replicate themselves and can keep creating replacements, which either become more stem cells, or develop into cells specific to a specialist need. However only Embryonic Stem cells can keep on replicating for a very long time (adult stem cells do not replicate in the same way). So the question then became, how to create Embryonic Stem Cells not from human embryos.

• Stem cells replicate by signalling themselves to do so. Scientists are still studying the signalling process that causes stem cells to replicate either as additional stem cells or ‘specialised cells’.

A ‘specialised cell’ is one that performs a specific function – such as a muscle cell, heart cell, or red blood cell.

A stem cell becomes a ‘specialised cell’ through ‘differentiation’, which involves many stages as the cell receives ‘signals’ from inside the cell (from the cell’s genes) and from outside the cell (from neighbouring cells).

Hence stem cells placed in a specific organ can receive signals from other specialist cells within the organ, to replicate as new specialised cells to help perform the specialist function of that organ.

Specialised cells cannot then become other types of specialised cell, but stem cells can become any type of specialised cell.

Embryonic Stem Cells are able to replicate more effectively and for longer than adult stem cells. A Clinic in Cyprus has devised a way of generating embryonic stem cells from a patient’s own skin cells and is using patients own Embryonic Stem Cells cultivated from their skin, for anti-ageing treatments and other treatments.