The micro RNA target paradigm: a fundamental and polymorphic control layer of cellular expression

Evidence is emerging that micro RNA (miRNA) is an important and potentially polymorphic regulatory layer for silencing gene expression in vivo. Knowledge of miRNA targeting may help to elucidate the function of many human genes in common diseases, providing a powerful target validation technology. Accurate in silico prediction of miRNA targets in mRNA is a critical capability, allowing effective evaluation of the impact of variation on the creation, strengthening, weakening and destruction of miRNA binding sites. Application of such analyses identifies thousands of single-nucleoticle polymorphisms, which may potentially impact miRNA regulation of mRNA. The authors believe this information may offer a real opportunity to study miRNA function at a number of levels. First, sequence-focused analysis will help to define the functional boundaries of miRNA target binding. Second, one may be able to identify miRNA target variants in mRNA with a direct role in human disease, which may be valuable therapeutic targets.