Systems Biology of MicroRNA

MicroRNAs are a class of small non-coding RNAs that has a significant role in regulating almost all life processes. They were first discovered in nematodes and subsequently in flies, fishes, birds, reptiles and mammals. It has been experimentally validated that microRNAs run a parallel control system that determines the genotype and phenotypes of individuals. In humans, microRNAs remotely control physiological process at different levels. Their systematic regulation leads to the up-regulation, down- regulation or gene silencing of specific mRNA sequences that holds the key to several diseases. MicroRNAs have an undisputed role in tumorigenesis and several other diseases in humans; hence an in depth understanding of their regulatory mechanism is the need of the hour. In this review we discuss the biogenesis of microRNAs, what qualifies anmiRNA, biological roles of miRNA, methods to predict a mature miRNA and miRNA targets and a systems biology approach to the microRNA regulatory network in humans.