Nobel Prize for medicine goes to American scientists who worked on microRNA

This year's Nobel Prize for physiology and medicine has been awarded to two American scientists who discovered how "microRNA" controls the decoding of genetic information in living organisms.

Studying the tiny nematode worm C "elegans", Victor Ambros and Gary Ruvkun independently discovered that small sequences of RNA were essential in determining whether certain genes are turned into proteins that carry out life's functions.

"Their groundbreaking discovery revealed a completely new principle of gene regulation that turned out to be essential for multicellular organisms, including humans," said Olle Kampe, chair of the Nobel Prize Committee.

Until their discovery, molecular biologists thought they understood how life controlled the expression of genes: large proteins called transcription factors determined which genes get translated from DNA into its sister molecule RNA before being turned into proteins - to make new skin, muscle, hormones, or anything else.

The discovery of microRNA was initially thought to be "an oddity peculiar to a small worm", according to Mr Kampe.

But Mr Ambros and Mr Ruvkun showed microRNA is found in nearly all complex life forms and plays a fundamental role in regulating how organisms function.

Also, when they misfunction. Errors in microRNA were since found to cause chronic lymphocytic leukaemia, a form of blood cancer.

Since the discovery, new research is exploring the involvement of microRNA in all aspects of biology and many other disease types including other cancers, obesity and heart disease.

The discovery doesn't have the same immediate application as last year's Nobel Prize in medicine, which also went to an RNA discovery - using the molecule to make vaccines against cancer and diseases like COVID-19 - but it is so fundamental it is likely to lead to new insights for medicine.