Micro-ribonucleic acid and carcinogenesis: Breast cancer as an example

MicroRNAs (miRNAs) are a class of small non-coding RNAs that have unique functions at post-transcriptional level (epigenetics). MiRNAs play a pivotal role in controlling gene expression at various levels including differentiation, cell-cycle regulation, apoptosis and many others in mammals as well as in many organisms. Recently, there has been greater understanding of the contribution of dysregulation of miRNA into disease status in particular carcinogenesis. In this review, we will discuss miRNA discovery, nomenclature, function, contribution of their dysregulation into disease status in particular carcinogenesis and their potential role as biomarkers.