MicroRNAs: reguladores clave de la expresión génica.

The discovery of novel gene regulatory systems under the control of small RNAs has had a significant impact on molecular biology. MicroRNAs (miRNAs) are a class of small non-coding RNAs (those that do not encode protein) that regulate gene expression post-transcriptionally. They bind with imperfect complementary to their target messenger RNAs (mRNAs), generally within the 3′-untranslated region, and repress protein production by destabilizing the mRNA and translational silencing. Large numbers' of miRNAs have been identified in the genomes of various species including human; yet the number of the miRNA is still rising due to the combined efforts of molecular biology and bioinformatic prediction. It has been reported that this molecules regulate cellular functions, therefore not surprising that microRNAs are implicated in a wide variety of diseases (i.e. cancer and diabetes mellitus). The purpose of this review is to provide current information on miRNA synthesis and the progress in the understanding of the mechanisms of miRNA-mediated gene silencing, as well as the potential use of miRNAs for diagnosis and therapy of diseases. [ABSTRACT FROM AUTHOR]