Timeline of RNAi Discovery View image detail
Drugs based on RNA interference (RNAi) are believed by many to be the next major class of human therapeutics. This potential has been recognized with the 2006 Nobel Prize for Medicine awarded to Craig Mello and Andrew Fire for their discovery of RNAi, and has resulted in major investments in RNAi-based drug development by large pharmaceutical and biotech companies. These investments include a series of transformative drug discovery alliances considered to be among the biggest in biotech history.
Recent breakthroughs in the understanding of the central role for RNA in a variety of cellular mechanisms have further facilitated the development of RNAi therapeutics.
The development of RNAi therapeutics has greatly benefited from an unprecedented advancement of the basic science relating to the role of RNA in an ever expanding spectrum of biological processes. While RNA had long been regarded to merely facilitate gene expression as a passive intermediate and structural component of the protein expression apparatus – or operating in a 'messenger' capacity -- it is now clear that RNA has many of the genetic, regulatory, and catalytic properties formerly thought to be possessed only by DNA and proteins.
The original function of the RNAi mechanism, which still operates in many invertebrates today, was that of a cellular RNA-based immune system designed to ‘interfere’ with the uncontrolled production of aberrant RNA molecules, which could be interpreted by the body as an opportunistic viral infection. Like our natural adaptive immune response, the RNAi mechanism is extremely specific in targeting these RNA molecules. In fact, they are identified for degradation by well-defined complementarity rules between the targeting small RNA and target messenger RNA (mRNA).