MicroARNs: una visión molecular

micrornas are small rnas of approximately 22 nucleotides in length that participate in the regulation of many cellular processes and it alteration is associated with the development of different pathologies in particular, cancer. using bioinformatics tools is possible determine their wide distribution in the genome and their functions in different tissues. mostly of micrornas are produced in a canonical way from a long primary transcript, in a sequential process of two reactions guided mostly by two enzymes: drosha in the nucleus and dicer in the cytoplasm. however, it has been described some pathways non-canonical for the generation of micrornas. the aim of this review is to describe the generation process of micrornas and the machinery involved in their generation for the purpose of achieving a better understanding of the different processes they are involved. salud uis 2011; 43 (3): 289-297