A radical new Hepatitis-C drug is currently being trialed in the Netherlands. It is an entirely different type of drug, which targets minuscule snippets of RNA in our cells. These RNA snippets, called microRNA, are single stranded RNA molecules of 21-23 nucleotides in length that regulate gene expression in animals, and will therefore block the production of proteins.
The drug currently being tested is an anti-microRNA, designed to inhibit the action of miR-122, a microRNA found almost exclusively in the liver. This drug slows replication of the hepatitis C virus, but can also cause levels of cholesterol in the bloodstream to fall by up to 40 per cent. Interestingly, the author of the article also suggests that microRNAs play a direct role in cancer. citing an example involving white blood cell cancers, which are allegedly associated with abnormally high expression of microRNAs.
One interesting feature of microRNA is its alleged ability to turn stem cells into specialised cells. In particular, human stem cells were converted to heart progenitor cells using specific microRNA molecules. Theses findings also raise the possibility that microRNA cells may be able to do the opposite: make specialised cells revert back to a stem cell like state.
Also, by inserting artificial versions of microRNAs into cells, researchers have shown that it is also possible to turn off whole sets of genes. This is of particular importance to gene therapy, and could have massive implications in future.
Reference
http://www.newscientist.com.ezproxy.library.uq.edu.au/article/mg19826621.800-micrornas-the-cells-little-emperors.html?full=true
