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This year’s Nobel Prize for Medicine or Physiology has been awarded to John Gurdon (79) and Shinya  Yamanaka (50) for work that lead to the understanding that mature specialised cells could be ‘reprogrammed’ back towards a state that was not specialised to any one purpose, but open to become many kinds of cells.

Formally the citation is “for discovery that mature cells can be reprogrammed to become pluripotent”.

This work has many potential areas of use including testing how bodies grow and develop, and disease treatment. Yamanaka, for example, aims to create a ‘bank’ of stem cells from foetal blood cells.

This pair had previously been jointly awarded the 2009 Lasker Prize for this line of research. There is a good explanation of their work with some illustrations showing a quick outline of what was done on the Lasker Prize website.

Those wanting a very brief and overly simplified ‘gloss’ on this may read on:

Cells in our body grow from general-purpose cells that can become many types of specialised cells. These ‘stem’ are what we call pluripotent – able to develop into many kinds of cells. It had once been thought that this process was irreversibly, that once a cell was specialised to be a particular type of cell it could not be reversed “back” to become a stem cell. These researchers shown that you could, in fact, reprogram mature cells to become stem-like, able to grow into different kinds of cells.

There are two basic ways this was demonstrated.

Each cell has a nucleus – the organelle in our cells that holds our genes. In the first method to make a mature cell pluripotent, the nuclei (plural of nucleus) of early embryo cells were transferred to mature cells whose nuclei had been destroyed. In this transfer, the ability of the cell to become like the earlier state in the embryo was also transferred and some of these cells were able to grow into mature cells and animals (tadpoles and frogs). This line of work was done by John Gurdon.

More recently another approach was to transfer particular genes, rather than whole nuclei. Yamanaka drew up a list of genes that might confer pluripotency, first finding that 24 genes transferred at once would do the trick. (This is a quite a technical achievement, beyond just being smart thinking.) In later work his group showed that just 4 gene were needed: Oct3/4, Sox2, c-Myc, and Kif4.

The work of many other researchers was used by these two scientists, both before their work and during their work, but these two researcher made key achievements that have led to the work of stem cell biologists today.


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