What is microRNA and why did its discovery merit this year’s Nobel Prize for Medicine?

This year, the Nobel Prize in medicine went to Victor Ambros, currently a Professor of Natural Science at the University of Massachusetts Medical School, and Gary Ruvkun, a Professor of Genetics at Harvard Medical School. The two men won the award for their discovery of microRNA. One of the key questions of science is figuring how how can we have such differentiated cells–brain cells, muscle, bone, nerve–when all cells have the same DNA. The key is gene regulation where each cell only selects the DNA instructions which are relevant to its particular function. A key question is how this gene regulation takes place.

Victor Ambros and Gary Ruvkun were interested in how different cell types develop. They discovered microRNA, a new class of tiny RNA molecules that play a crucial role in gene regulation. 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 one thousand microRNAs. Their surprising discovery revealed an entirely new dimension to gene regulation. MicroRNAs are proving to be fundamentally important for how organisms develop and function…

Many of the initial discoveries around microRNA were made through research on a 1 mm long roundworm known as C. elegans. They found that very small sections of RNA–now known as microRNA–don’t code for specific proteins but rather inhibit production of specific proteins. The implications of microRNA in the real world are vast.

We know from genetic research that cells and tissues do not develop normally without microRNAs. Abnormal regulation by microRNA can contribute to cancer, and mutations in genes coding for microRNAs have been found in humans, causing conditions such as congenital hearing loss, eye and skeletal disorders.

You can read more about microRNA as well as Nobel laureates Ambros and Ruvken here.