ABSTRACT
RNA interference (RNAi) is a Nobel Prize-winning, robust, powerful and sequence-specific regulatory tool for posttranscriptional gene silencing that uses double-stranded, single-stranded and short hairpin RNA molecules. It is a gene silencing technique that uses small non-coding RNA (ncRNA) such as small interfering RNA (siRNA), microRNA (miRNA), short hairpin RNA (shRNA) and PIWI-interacting RNAs (piRNAs), among others. They can form perfect or imperfect Watson-Crick base pairing with the target messenger RNA (mRNA), resulting in gene silencing or the translational attenuation of target mRNAs. The potential of RNAi in manipulating and supressing the augmented gene expression of disease-linked genes has made it a promising tool in therapeutic applications and drug development. Despite having a few shortcomings such as off-target effects, mediated toxicity, inefficient delivery into the target system and elicitation of the innate immune system, many RNAi candidates are currently under Phase I and Phase II clinical trials for a targeting error in the genetic code that leads to diseases such as cancer, neurodegeneration and cardiovascular diseases, among others. This chapter focuses on the present understanding of RNAi technology, its mechanism of action and its current standing as a major therapeutic approach in the field of medical biotechnology with a special focus on the candidates currently under clinal trial.
