A micro-Nobel for medicine

The 2024 Nobel Prize in Medicine was awarded to Victor Ambros and Gary Ruvkun on the following grounds: 'for their discovery of microRNA and its role in mRNA maturation'.

MicroRNA refers to a class of small non-coding RNA molecules, approximately 20-25 nucleotides in length, playing a critical role in regulating gene expression. 'Non-coding' refers to the fact that the cell does not utilize the genetic information carried by the molecule to produce specific proteins, unlike known RNA molecules such as mRNA, or messenger RNA, and tRNA, which transports amino acids, the fundamental building blocks of proteins. MicroRNA regulates the amount of protein produced by a gene, acting at the post-transcriptional level. Their primary function is to modulate gene activity, influencing various critical biological processes. These small molecules act as switches, initiating or inhibiting gene expression and, consequently, the production of proteins.

One of the most remarkable aspects of microRNA function is cell differentiation. We know that every cell in an organism (except the red blood cells in mammalian blood) has an identical copy of the individual's entire genome. But cells do different things depending on the tissue and organ they help form: skin cells protect the body and are extremely different from liver or brain cells, neurons, which make us think. How do cells carrying the same genetic information assume such diverse forms and functions during body development? This is where the regulatory properties of microRNA come into play: by switching specific genes on or off, these small molecules cause a cell to become part of the skin, brain or bone. MicroRNA is also involved in the development or inhibition of certain diseases, such as tumors, and neurovegetative diseases, such as Alzheimer's.

Lastly, these molecules help cells respond to stress by swiftly regulating the expression of specific genes enabling the body to adapt to environmental changes.