Oxygen is essential to all animal and human life but sometimes there is less oxygen in the air around us, for example at higher altitudes. Cells may also take up less oxygen due to anaemia or injury.

So how do cells adapt to situations in which there is less oxygen available? This year’s Nobel Laureates - Gregg Semenza, Peter Ratcliffe and William Kaelin - have identified the genes and substances that regulate the use of oxygen in the cells.

EPO

When oxygen is in short supply, the body makes a hormone known as EPO, which boosts the production of red blood cells. Cyclists know all about this – as does Gregg Semenza. In tests on genetically modified mice, Semenza showed which genes (apart from the one associated with EPO) become more active when oxygen levels are low. British researcher Peter Ratcliffe also worked on this topic. Their research established that all cells in the body react to a lack of oxygen, not only the kidney cells which produce EPO.

But what about the exact workings at cellular level? Semenza discovered a protein that attaches itself to the DNA, depending on the amount of oxygen available. This signalled the beginning of the breakthrough.

Cancer

It was then that cancer researcher William Kaelin arrived on the scene. He was studying a particular type of hereditary cancer: von Hippel-Lindau’s disease. A protein that prevents cancer in other people was absent in his patients and also turned out to be involved in regulating oxygen in the cell.

Spurred on by these discoveries, the researchers were eventually able to unlock the molecular mechanism behind oxygen regulation at cellular level.

The Nobel Prize in Physiology or Medicine is the first of this year’s Nobel Prizes to be announced. Two Dutch researchers have won the prize in the past: Niko Tinbergen in 1973, for his research on the behaviour of social animals such as bees and birds, and Christiaan Eijkman in 1929, for his work on vitamins.

The three Laureates will share the prize of 9 million Swedish kronor, the equivalent of around €825,000.