US scientists Victor Ambros and Gary Ruvkun have been awarded the 2024 Nobel Prize in Physiology or Medicine for their research on microRNA. Their discoveries shed light on the emergence of complex life on Earth and the diverse tissues that make up the human body. MicroRNAs play a crucial role in regulating genes, which are the instructions for life in all organisms, including humans. The winners will share a prize fund of 11 million Swedish kronor (£810,000).
Every cell in the human body contains the same genetic information encoded in our DNA. However, despite this identical starting material, human cells vary greatly in form and function.
Nerve cells transmit electrical impulses, heart cells beat rhythmically, liver cells act as metabolic powerhouses, kidney cells filter urea from the blood, retinal cells detect light, and white blood cells produce antibodies to fight infections. This diversity arises from gene expression.
US scientists were the first to discover microRNAs and their role in controlling gene expression in different tissues.
The Nobel Assembly of Sweden’s Karolinska Institute selects the winners of the medicine and physiology prize. They stated: “Their groundbreaking discovery revealed a completely new principle of gene regulation that turned out to be essential for multicellular organisms, including humans. It is now known that the human genome codes for over 1,000 microRNAs.”
Without the ability to control gene expression, every cell in an organism would be identical. MicroRNAs have been crucial in enabling the evolution of complex life forms.
However, abnormal regulation by microRNAs can lead to cancer and various conditions, such as congenital hearing loss and bone disorders. A severe example is DICER1 syndrome, which causes cancer in multiple tissues due to mutations affecting microRNAs.
Professors Victor Ambros and Gary Ruvkun, aged 70 and 72 respectively, work at the University of Massachusetts Medical School and Harvard Medical School. They conducted their groundbreaking research on the nematode worm, C. elegans.
Their experiments focused on a mutant worm that failed to develop certain cell types. They discovered that tiny pieces of genetic material, known as microRNAs, were crucial for the worm’s development.
Here’s how it works:
- A gene or genetic instruction is contained within our DNA.
- Our cells make a copy of this gene, called messenger RNA (mRNA), which you might remember from COVID-19 vaccines.
- This mRNA travels out of the cell’s nucleus and instructs the cell’s protein-making factories to produce a specific protein.
- MicroRNAs interfere by attaching to the mRNA, preventing it from functioning.
- Essentially, the microRNA stops the gene from being expressed in the cell.
Further research showed that this process is not unique to worms but is a fundamental component of life on Earth.
Prof. Janosch Heller from Dublin City University expressed his delight at the prize being awarded to Profs. Ambros and Ruvkun. He noted that their pioneering work on gene regulation by microRNAs has paved the way for groundbreaking research into novel therapies for diseases like epilepsy and has highlighted the intricate machinery that tightly controls cellular functions.
