It was an unusually quiet audience that on Monday received the announcement of this year's prize winners in physiology or medicine. Most people probably needed to prick up their ears extra when the Nobel Assembly explained what the discovery was about – microRNA.
MicroRNA has proven to be crucial for our cells becoming what they become – intestinal cells or muscle cells, for example – and is an important part of what is called gene regulation.
We thought we understood what makes certain genes become activated and others not. But Ambros and Ruvkun showed that there was a whole layer of control and it was micro-RNA, says Sten Linnarsson, professor of systems biology and member of the Nobel Assembly that selects the winners.
"Enormous consequences"
When DNA is to be copied, it must first be copied into a nearly identical molecule called RNA, which often leads to protein formation. But the small microRNA molecules can, simply put, prevent this. They function as an on-off switch that hides parts of the message from the genes.
The prize winners have, on their own, been interested in a small worm, with the scientific name Caenorhabditis elegans. The worm contains only 1,000 cells, but forms many of the same tissues as in humans.
The fact that the worm is so small, yet complex, makes it suitable for studying how different tissues are formed and develop. The researchers studied different types of mutant strains in the worms to understand their function and connection to protein production.
When they then compared their respective findings with each other, it led to the groundbreaking discovery, which describes the mechanism for how genes are regulated. The result was presented in 1993 in the journal Cell.
No clear application
In contrast to the 2023 medicine prize, which had a direct connection to the covid-19 vaccine, this year's prize is purely basic research. There are no direct applications today, but microRNA is included in many studies. For example, it is common in cancer diseases that microRNA is misregulated.
MicroRNA regulates almost all genes and is therefore involved in almost all diseases, but often in a very complex way, says Sten Linnarsson.
One who thinks this year's prize is top-notch is Fredrik Söderbom, at Uppsala RNA Research Center. He has himself researched with one of the prize winners.
The discovery has enormous consequences, because proteins are often what build up animals and plants and regulate how we function. If it's not exactly the right amount of proteins, it often goes wrong and can lead to diseases. So it's extremely important that we get the right amount of proteins in the right cells. And that's where microRNA helps to control it.
At first, people thought that microRNA was specific to the worm, but after several years, it has been found in other living things. Söderbom thinks the prize winners are well-deserved.
I would have given up a little. But it was completely right, it was spot on, he says.
Victor Ambros is an American molecular biologist, active at the University of Massachusetts Medical School. He is 70 years old, born in Hanover in the state of New Hampshire.
Gary Ruvkun is also an American molecular biologist, active at Massachusetts General Hospital and professor of genetics at Harvard Medical School in Boston. He is 72 years old and from Berkeley in California.
