Geneticists Andrew Fire and Craig Mello richly deserve to share this year’s Nobel Prize for fashioning an incredibly powerful lab tool to treat a wide spectrum of diseases. They discovered that ribonucleic acid (RNA) — the lesser known cousin of the molecule of inheritance, DNA — could silence genes by turning them off. DNA uses a type of RNA called messenger RNA to send manufacturing instructions of proteins to the cell. Sometimes, though, a process called RNA interference, or RNAi, disrupts the messenger RNA and the instructions get deleted. Fire and Mello figured out how this happens.
As its name implies, RNAi interferes with the normal activity of genes, as short RNA molecules ‘silence’ the activity of a particular gene. In other words, RNAi halts the production of proteins produced from the genes of a chromosome. In fact, RNAi is a universal mechanism that is used by all living organisms for controlling gene activity. Everything from plants and fungi to fruit flies, mice and humans use RNAi to switch off genes. Scientists believe it evolved as a protection against viruses by targeting and switching off vital viral genes.
The research done by Fire and Mello shows how it can be used to switch off potentially harmful genes — either the body’s own mutations or viral invaders. This is probably the biggest advance in healthcare since the development of antibiotics. Scientists may soon be able to design anti-viral drugs that can cripple the ability of infectious agents to attack human cells.