Q. ‘RNA interference (RNAi)’ technology has gained popularity in the last few years. Why?

  1. It is used in developing gene silencing therapies.
  2. It can be used in developing therapies for the treatment of cancer.
  3. It can be used to develop hormone replacement therapies.
  4. It can be used to produce crop plants that are resistant to viral pathogens.

Select the correct answer using the code given below.

  • 1, 2 and 4
  • 2 and 3
  • 1 and 3
  • 1 and 4 only

Answer: (a) 1, 2 and 4

RNA interference (RNAi)
  • RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expressionby double-stranded RNA, through translational or transcriptional repression.
    • Historically, RNAi was known by other names, including co-suppression, post-transcriptional gene silencing (PTGS), and quelling.
    • RNAi is now known as precise, efficient, stable and better than antisense therapy for gene suppression.
  • Two types of small ribonucleic acid (RNA) molecules, microRNA (miRNA) and small interfering RNA (siRNA), are central to components to the RNAi pathway. Once mRNA is degraded, post-transcriptional silencing occurs as protein translation is prevented. Transcription can be inhibited via the pre-transcriptional silencing mechanism of RNAi, through which an enzyme complex catalyzes DNA methylation at genomic positions complementary to complexed siRNA or miRNA.
  • RNAi has an important role in defending cells against parasitic nucleotide sequences (e.g., viruses or transposons) and also influences development of organisms.
Gene Silencing
  • Gene silencing refers to a mechanism by which cells shut down large sections of chromosomal DNA. It is generally used to describe the “switching off” of a gene by a mechanism other than genetic modification.
  • Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene.
  • Gene silencing can occur during either transcription or translation and is often used in research. In particular, methods used to silence genes are being increasingly used to produce therapeutics to combat cancer and other diseases, such as infectious diseases and neurodegenerative disorders.
  • Gene silencing is often considered the same as gene knockdown. When genes are silenced, their expression is reduced. In contrast, when genes are knocked out, they are completely erased from the organism’s genome and, thus, have no expression.