New Advances in RNAs

Since the discovery of the first microRNA gene, lin-4, in Caenorhabditis elegans in 1993, many of this small regulatory genes have been reported in plants, viruses, and various kinds of animals. This announced a new world of RNA molecules, which subverted our traditional thinking about RNA. In this review, I summarized the main findings from researchers at different laboratories on microRNAs importance, functionality, production, and different aspects of their biologic activities. A narrative literature overview of relevant papers known to the author and that were retrieved from PubMed is presented. MicroRNA, a nonprotein-coding small RNA with almost 21 – 23 nucleotides in length, is an essential regulatory apparatus in the cells and their environment. They are crucial molecules for development, evolution, cellular differentiation, proliferation, embryogenesis, and cell death. Two classes of microRNAs exist: small temporal RNA—stRNA (miRNAs) and small interfering RNA— siRNAs (RNAi). The latter is a useful tool for the diagnosis, treatment, and prevention of diseases particularly cancer and viral diseases. There have been tremendous research regarding various aspects of these genes silencing and regulatory molecules which are preserved in all kinds of creatures. Currently, about 1% of the known human genes encode microRNAs.