M EDICAL E THICS Stem Cells

L EARNING I NTENTIONS : Understand what both types of stem cell are. Be able to explain why scientists want to do research with stem cells. Understand the ethical implications of stem cell research.

T HERE ARE TWO TYPES OF STEM CELL Embryonic stem cells Adult stem cells

E MBRYONIC STEM CELLS

Cells make up all parts of the human body, we are a collection of cells.

E MBRYONIC STEM CELLS Because embryonic stem cells can become any type of cell in the body: Brain cell Skin cell Tooth cell Liver cell Heart cell We call them pluripotent

E MBRYONIC STEM CELLS This has the potential to be a very useful medical tool to treat a wide range of diseases or medical conditions.

H UMAN E AR GROWING ON A MOUSE !

A DULT S TEM C ELLS Adult stem cells are the cells that replace other cells in our body that have become damaged. So if we drink too much on a night out, some of our liver cells will be damaged and need to be replaced.

A DULT S TEM C ELLS Adult stem cells will only naturally turn into cells of a particular type. A brain cell can only replace a brain cell A liver cell can only replace a liver cell Adult stem cells are not naturally pluripotent.

A DULT S TEM C ELLS Scientists have had great success recently reprogramming adult stem cells so they become pluripotent. They are called induced pluripotent stem cells.

A DULT S TEM C ELLS However, the induced pluripotent stem cells tend to accumulate mutations and suffer abnormal patterns of gene activity. In other words they sometimes go on to form tumours. Having said that there have been lots of successful treatments performed.

E MBRYONIC S TEM C ELLS Cells are normal and do not form tumours. No practical applications as yet.