Why is microRNA discovery a big leap? Premium

2024 Medicine Nobel for discovery of microRNA: What have the Nobel laureates achieved by unlocking a secret on how different types of cells develop? How will it help in the field of molecular biology? Why is an understanding of genes important? What happens if gene regulation goes awry?

The Nobel Committee announced on October 7 that the Nobel Prize for Medicine or Physiology would be shared by Victor Ambros and Gary Ruvkun “for the discovery of microRNA and its role in post-transcriptional gene regulation,” thereby unlocking a secret on how different types of cells develop.

The human body is probably the most complex puzzle that humans are still trying to make sense of. Every time there is a better understanding and a piece slides into place with a resounding click, then it is an occasion for celebration. For a Nobel Prize too perhaps. This year’s awardees of the Nobel Prize for Medicine — Ambros and Ruvkun — did slide in a couple of pieces into the right slots in the massive puzzle that suddenly opened our eyes to understanding how different cell types develop.

Editorial | Regulation role: On the 2024 Medicine Nobel

Consider this: Every cell in the body contains the same chromosome, so every cell contains exactly the same set of genes and presumably, the same instructions. But different cell types have different, unique characteristics. It confounded the imagination until Ambros and Ruvkun came along. Their discovery offered a plausible explanation for the conundrum. The piece of the puzzle was called microRNA, a new class of tiny RNA molecules that play a crucial role in gene regulation. As the Nobel announcement statement said, their groundbreaking discovery revealed a completely new principle of gene regulation essential for multicellular organisms, including humans.

It is now known that the human genome codes for over one thousand microRNAs. Genetic information flows from DNA to messenger RNA (mRNA), via a process called transcription, and then on to the cell for production of protein. There, mRNAs are translated so that proteins are made according to the genetic instructions stored in DNA.

The key is in the precise regulation of gene activity so that only the correct set of genes is active in each specific cell type. Additionally, gene activity must be continually fine-tuned to adapt cellular functions to changing conditions in our bodies and environment. If gene regulation goes awry, it can lead to serious diseases. Therefore, understanding the regulation of gene activity has been an important goal for many decades.

Ambros and Ruvkun, both American biologists, were together in their post-doctoral period at the H. Robert Horovitz lab in the 1980s, and their interest in cell development probably had its spark there. “It was the moment,” Ruvkun said later, “when recombinant DNA was just starting to take off and it was obvious that it was a revolution and I wanted to be part of that.” As they say, great achievements have humble beginnings, and this duo started appropriately enough with a humble 1 mm long roundworm. This creature was not an odd choice though: it possessed many specialised types of cells, such as nerve and muscle cells, making it a convenient model to study a complex genetic regulation process across species, one that was conserved throughout evolution.