Nobel Prize in Medicine awarded to scientists for work on microRNA | Nobel Prizes

The 2024 Nobel Prize in Physiology or Medicine was awarded to two scientists for their work on tiny RNA molecules that help cells control which proteins they produce.

Victor Ambros of the University of Massachusetts Medical School and Gary Ruvkun of Harvard Medical School and Massachusetts General Hospital received the award for the discovery of microRNA and its role in post-transcriptional gene regulation.

As announced by the Nobel Assembly at the Karolinska Institute in Stockholm, Sweden, the winners will receive a prize of 11 million Swedish crowns (around £810,000) in equal shares.

Their work helped explain how all of our cells can produce different proteins despite carrying the same DNA. For example, nerve cells and muscle cells are highly specialized even though they contain the same DNA.

“The groundbreaking discovery of microRNA has introduced a new and unexpected mechanism of gene regulation,” said Olle Kämpe, vice chairman of the Nobel Committee for Physiology or Medicine. “MicroRNAs are important for our understanding of embryonic development, normal cell physiology and diseases such as cancer.”

In the nucleus of our cells, genetic information is stored as a double-stranded molecule, DNA. To create proteins – molecules that perform a variety of functions in our cells – a section of DNA or a gene is copied to create a single-stranded molecule called messenger RNA (mRNA). This mRNA acts as an “intermediary,” delivering the instructions for a protein to the protein-making machinery in the cells.

“The question is: What determines that only the right genes are transcribed into mRNA at the right time and then translated into the right tissue-specific proteins?” said Kämpe.

For many years, scientists thought they had the answer in proteins called transcription factors. These bind to DNA and activate or prevent the production of mRNA.

But as Ambros and Ruvkun revealed, that wasn't the whole story.

Working with a type of tiny roundworms known as Celegans The pair independently illuminated a different mechanism and published seminal papers in the early 1990s.

Their research showed that tiny sections of RNA, known as microRNA, can bind directly to mRNA, preventing the instructions for the corresponding protein from being “read” by the protein-making machinery.

“For a long time, however, microRNA was considered a peculiar curiosity Celegans“said Kämpe. However, in the years that followed, additional microRNAs were discovered, so that today more than a thousand genes for different microRNAs are known in humans.

Later work by various teams found that microRNA can not only bind to mRNA to block the production of proteins, but can also lead to mRNA degradation.

And there were other discoveries. “Each microRNA regulates multiple mRNAs and each mRNA is often regulated by many different microRNAs, creating a robust system of gene regulation,” Kämpe said.

Ambros and Ruvkun are no strangers to each other: the two of them simultaneously conducted postdoctoral research in the laboratory of Robert Horvitz, who himself received the Nobel Prize in Physiology or Medicine in 2002.

Prof Venki Ramakrishnan, who won the Nobel Prize in Chemistry in 2009 for his work in elucidating the structure of the cell's protein-making machinery, welcomed the news.

“This is a very well-deserved and long-awaited award that shows that small RNAs can regulate which genes are expressed in different cell types. It has opened up a whole new field of biology and has far-reaching implications,” he said.

But he added: “It is a shame that David Baulcombe, whose laboratory discovered a similar phenomenon in plants and shared the Lasker Prize with Ambros and Ruvkun in 2008, was not included in the prize.”

Thomas Perlmann, secretary general of the Nobel Assembly, said he was able to reach Ruvkun in the United States on Monday morning and awaken the scientist.

“His wife answered, and it took him a long time to get on the phone and sounded very tired, but pretty quickly he got all excited and happy when he understood what it was about,” Perlmann said, adding that he didn't yet Ambros was able to reach him.

“I left a message on his phone and hope he calls me soon,” he said.

The 2024 Nobel Prize in Physics will be announced on Tuesday, with the Chemistry Prize following on Wednesday.