From decoding the genetic blueprint to rewriting its instructions, scientists have developed increasingly powerful ways to control gene expression. A pivotal breakthrough came in 1998, when biologists Andrew Fire at Stanford University and Craig Mello at the University of Massachusetts Medical School discovered RNA interference (RNAi) in Caenorhabditis elegans, demonstrating that double-stranded RNA can trigger sequence-specific gene silencing. RNAi works by introducing double-stranded RNA that matches a target gene's messenger RNA , triggering its degradation before it can be translated into protein. This way, researchers can disrupt gene function across a wide range of model organisms for research, agriculture, and therapeutic use. In honor of The Scientist’s 40th anniversary, we look back at our coverage of the key advances that have shaped RNAi technology and its journey from basic research to the clinic.
2001: RNAi in Mammalian Cells
RNAi was successful in model organisms like C. elegans and the fruit fly, but transitioning such a technique to mammalian cells proved challenging. The introduction of long double-stranded RNA produced toxic responses. In 2001, biochemist Thomas Tuschl and colleagues at the Max Planck Institute for Biophysical Chemistry circumvented this hurdle by using synthetic small interfering RNAs (siRNAs) that could silence genes in mammalian cells without triggering the toxic antiviral response associated with long double-stranded RNA. The finding opened the door to RNAi as a practical research tool and therapeutic strategy in mammals.
2005: RNAi Therapeutics Enter Clinical Trials
While traditional gene therapy was built on the idea that diseases caused by the absence or dysfunction of a gene could be treated by restoring its function, RNAi introduced a fundamentally different approach. Rather than adding genes, RNAi selectively silences disease-causing genes by targeting their messenger RNA. This article explores the promise of this technology, as well as the early challenges encountered in translating this from the laboratory to RNAi clinical trials.
2006: RNAi Takes Home the Nobel Prize
Since their landmark study in 1998, Fire and Mello saw a new field in RNA research emerge. Years later, they both received the Nobel Prize in Physiology or Medicine for discovering RNAi. The award recognized the breakthrough as one that transformed the study of gene function and inspired a new generation of RNAi therapeutics.
2007: New Tricks for Delivering siRNAs
As RNAi therapies advanced, researchers tackled one of the field's greatest obstacles: delivering siRNAs safely and efficiently to the right cells and tissues. New delivery strategies, such as nanoparticles and antibodies, improved the precision and therapeutic potential of RNAi, bringing the technology closer to clinical reality.
2013: RNAi Therapy Shows Clinical Promise in Lowering Cholesterol
Here, an siRNA-based drug exhibited promise for patients taking cholesterol-lowering medication. Early clinical results revealed durable reductions in cholesterol-related targets, providing some of the strongest evidence yet that RNAi drugs could work safely and effectively in patients.
2018: The First Commercial RNAi Therapeutic
Two decades after RNAi's discovery, the field reached a major milestone. The US Food and Drug Administration and the European Commission approved patisiran (Onpattro), developed by Alnylam Pharmaceuticals, for a rare genetic disease called hereditary transthyretin amyloidosis, which causes abnormal protein build up in tissues. As the world's first RNAi therapeutic—and the first lipid nanoparticle-delivered siRNA drug—its approval validated decades of research and established gene silencing as a new therapeutic modality.
2020: The Growing Success of RNAi Therapies
With multiple RNAi drugs approved and more in development, RNAi has grown into a clinically proven therapeutic platform. The article explores how advances in delivery technologies and target selection fueled the field's rapid progress.
From a surprising discovery in nematodes to a new class of approved medicines, the history of RNAi illustrates how fundamental biological research can reshape medicine. While the journey took 20 years from RNAi’s discovery to the first RNAi FDA-approved drug, its rapid clinical expansion has established gene silencing as one of the most promising modalities in modern drug development.
