An Overview of MicroRNA

Abstract

Recently, microRNAs (miRNAs) have emerged as central posttranscriptional regulators of gene expression. miRNAs regulate many key biological processes, including cell growth, death, development and differentiation. This discovery is challenging the central dogma of molecular biology. miRNAs have been known to be involved in development, cell proliferation and apoptosis. Several reports have recently shown that miRNAs might also be involved in filtering out gene expression noise by regulating positive regulatory loops in cells. Loss- or gain-of-function of specific miRNAs appears to be a key event in the genesis of many diverse diseases. Recent studies have shown that miRNAs are important during heart development and adult cardiac physiology, and modulate a diverse spectrum of cardiovascular functions in vivo. miRNAs have been shown to regulate pathways controlled by genes like p53, MYC and RAS, which are closely related to cancer. Single-nucleotide polymorphisms (SNPs) of miRNA binding sites are associated with gene expression levels of the target alleles and cancer. Finally, these miRNA studies also have implications for understanding complex pathways, e.g., interactions between miRNAs, cell signaling and transcription factors, involved in human diseases, and can lead to potential opportunities in manipulating miRNAs as therapeutic targets.