miRNA: from junk to 2024's Nobel Prize Physiology or Medicine

I vaguely remember learning about "junk RNA" during my last years of undergrad, sometime in the mid-'90s. Back then, non-coding RNA (ncRNA) was often dismissed as an oddity, something found in nematodes with no clear function or reason to exist.

That all changed in the early 2000s with the discovery of let-7, a type of  microRNA (miRNA). Surprisingly, it wasn’t just found in nematodes but also across a wide range of organisms, including plants, animals, and fungi (here, here, and here). This discovery marked a before and after in our understanding of gene regulation, challenging the protein-centric view of that time. miRNAs turned out to be key regulators of gene expression, controlling everything from developmental processes to cellular differentiation and diseases like cancer. Importantly, they were also recognized as  post-transcriptional regulators, reshaping our understanding of non-coding RNAs as essential components of cellular biology.

Just a few hours ago, the Nobel Assembly at the Karolinska Institutet announced that this year’s Prize in Physiology or Medicine would go to Victor Ambros and Gary Ruvkun for their groundbreaking discovery of microRNA and its role in post-transcriptional gene regulation. What was once thought of as junk revealed a whole new layer of how genes are controlled—a fundamental insight into how organisms develop and function.

While there are still challenges in therapeutic applications, miRNA holds big potential for transforming cancer treatment. Researchers are actively exploring miRNA-based therapies, diagnostic tools, and precision medicine approaches, some of them highly promising.

For more scientific background, courtesy of The Nobel Committee for Physiology or Medicine, here

Image courtesy of theThe Nobel Committee for Physiology or Medicine. Ill. Mattias Karlén