Almost all biology students learn the fundamentals of gene expression, DNA contains information which is transcribed into RNA to create protein. Students however, are not taught of RNA Interference, the biological process where RNA molecules inhibit a gene’s expression, RNAi for short. While RNAi is a fairly new discovery, its use in modern biological research is groundbreaking. RNA Interference works by binding Double-stranded RNA molecules (siRNA) to a complementary messenger RNA. The enzymes Dicer and Slicer then cleave the chemical bonds which hold the messeger RNA in place and prevent it from delivering protein silencing instructions thus, the term, Gene Silencing. This phenomenon was first discovered by Richard Jorgensen in 1990 when he was trying to produce deeper purple colored petunias by introducing more purple pigment genes to the flower. To his surprise, the purple petunia turned completely white and got the opposite of his predicted result. At the time Jorgensen coined this effect, “Cosuppression”. It was not until 1998 that Andrew Fire and Craig, C Mello explained the process of RNAi and discovered its use in Caenorhabditis elegans (C. Elegans). In 2006 Fire and Mello won the Nobel Prize in Physiology or Medicine “for their discover of RNA Interference – gene silencing by double stranded RNA”. They utilized the nematode, C. Elegans due to its whole genome being sequenced. This unique characteristic allows for every gene to be tested
during RNAi. RNA interference is now applied in many forms of biological science from, Physiology to Biotechnology.
RNA Interference has been successfully applied in many fields of medicines used to treat issues such as, Parkinson’s and Lung Cancer. One study, sponsored by Alnylam Pharmaceuticals, Cambridge suggested that use of RNAi can be used to inhibit the production of the protein PCSK9. PCSK9 causes the destructions of receptors that clean up unnecessary LDL cholesterol in blood. Alnylam conducted an experiment consisting of 32 healthy patients to test the safety of an RNAi drug instead of how well it performed. A competing cholesterol therapy is in progress being run by the Paris based pharmaceutical company, Sanofi. Sanofi plans on using antibodies to target PCSK9 which could lead to an alternative to the commonly used statins drug. Out of the 32 patients in the most recent trial, 24 received a single dose of the RNAi drug. The results showed that the expression of PCSK9 dropped to a staggering average, 70% and a 40% decrease of LDL cholesterol levels. If the PCSK9 inhibition drug deems successful it is still not sure whether the drug will perform well from a business aspect.
Another application of RNAi is in Parkinson’s disease. Researchers at the National Institutes of Health have successfully used RNA Interference to uncover several genes which possibly represent new therapeutic targets for treating Parkinson’s disease. These discoveries may also be useful to other diseases cause by damage...