2024 NOBEL PRIZE WINNERS AWARDED FOR GROUNDBREAKING MICRORNA DISCOVERY!

Victor Ambros (left) and Gary Ruvkun (right), the two scientists who discovered microRNAs and their roles in regulating genes. Credit: Steve Jennings/Getty for Breakthrough Prize

                            

Possible cures for cancer and heart disease all rely on a teeny tiny bit of RNA. That's right!

Recently, the list of 2024 Nobel Prize Winners was announced. From that, we learn that scientists Victor Ambros (University of Massachusetts Chan Medical School) and Gary Ruvkun (Harvard Medical School) have been awarded the 2024 Nobel Prize in Physiology or Medicine for discovering microRNA and its job in controlling genes. But how is it that a minuscule strand of RNA could say when a protein should not be produced, and why is it so important?

HOW IT ALL BEGAN

In 1993, both Ambros and Ruvkun were studying the growth process of a transparent worm called Caenorhabditis elegant. Both scientists worked together to find out the key stages in the worm's growth, controlled by two genes - lin-4 and lin-14.

Ambros found no protein-producing gene in lin-4, but weirdly enough he found paltry amounts of RNA in his experiments with lin-4. He initially dismissed it as dirt. Lo and behold, it turns out to be the microRNA that would lead to his Nobel victory thirty-one years later (pun intended). 

It did not take him long to learn that it wasn't just any bits of dirt that he found turning up in his experiments. However, back then, microRNA wasn't called "microRNA". Instead, it was dubbed a short temporal RNA as it was produced at a specific time when the worm grows. 

On the other side, Ruvkun discovered that the lin-4 microRNA attaches on to part of the lin-14 mRNA and decreases the production of the mRNA's protein. By the way, mRNA is short for messenger RNA, which contains a specific code for ribosomes to produce a specific protein. 

Seven years later - Ruvkun discovers microRNA let-7, which is present in many animals, as well as in humans. 

HOW DO MICRORNAs CONTROL PROTEIN PRODUCTION?

To keep it short and simple, microRNAs bind to an area of the mRNA called the 3'-UTR (untranslated region) which ribosomes don't decode. Then, they destabilize the mRNA, making less mRNA available to be decoded, and prevent the mRNA from being decoded by the ribosomes. 

However, the exact mechanism of how it prevents the mRNA's translation is yet to be determined( work in progress!).

WHY ARE MICRORNAs SO SPECIAL?

The discovery of microRNAs has led to a whole new class of gene regulators, meaning it once again teaches us that despite technological advances in research throughout the past years, there's still a lot we have to learn about the molecular biology of our cells. 

Moreover, microRNAs are undergoing clinical trials for therapeutic applications. Scientists theorise that they could be used to treat heart disease, neurodegenerative diseases, heart diseases, cancer, and much more. 

For example, microRNAs could be used to prevent the mRNA of cancer-causing genes( oncogenes) from being decoded or it could be used to restore genes that prevent the formation of tumors( tumor suppressors).

Therefore, microRNAs could be extremely beneficial to medicine. 

Hats off to Ambros and Ruvkun for broadening our understanding of molecular biology and bringing us one step closer to revolutionary treatments for debilitating diseases!

I’d love to hear your thoughts on this discovery! What else do you think it could lead to? And feel free to share any topics you'd like me to cover in my upcoming blog posts. Thanks a lot for reading!

REFERENCES

1. Kessler, R. (2024). Nobel prize-winning discovery could lead to new therapies for heart disease and cancer. Nature. https://www.nature.com/articles/d41586-024-03212-9

2. Steitz, J. (2023). How microRNAs control the expression of genes: Insights from the 2023 Nobel Prize in Physiology or Medicine. Science News. https://www.sciencenews.org/article/microrna-2023-nobel-physiology-medicine

3. He, L., & Hannon, G. J. (2004). MicroRNAs: Small RNAs with a big role in gene regulation. Nature Reviews Genetics, 5(7), 522-531. https://pubmed.ncbi.nlm.nih.gov/19021530/#:~:text=miRNAs%20%28microRNAs%29%20are%20short%20non-coding%20RNAs%20that%20regulate,production%20by%20destabilizing%20the%20mRNA%20and%20translational%20silencing.

4. Bartel, D. P. (2021). Metazoan microRNAs. Cell, 173(1), 20-37. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8198729/#:~:text=In%20cancer%2C%20deregulated%20miRNA%20expression%20leads%20to%20tumor,attractive%20tools%20for%20the%20development%20of%20anti-cancer%20therapies.