MicroRNAs in health and disease--basic science and clinical applications

MicroRNAs (miRs) are small RNAs that fine-tune gene expression at posttranscriptional level. They are involved in virtually all physiological processes, such as development and differentiation, heart function, metabolism, haemostasis, and apoptosis. Anucleated human platelets were revealed to contain comparatively many different miR species relative to nucleated cells, suggesting a functional impact of miRs on these small cells. In recent years, numerous studies have established the significance of miRs in different physiological states. Sufficient evidence exists to suggest that miRs are involved in a range of diseases, including cancer and cardiovascular disorders. Aberrant expression levels of miRs are found in tissues and in sera from patients with different forms of malignant tumours. Utilising these miRs as biomarkers for disease is a valuable diagnostic strategy. In addition, a novel class of synthetic oligonucleotides, called antagomirs, has recently been introduced as efficient silencers of overexpressed miRs in cancer. Overall, miRs represent an important class of small RNAs with a huge impact on health and disease. Future studies will further illuminate the potential value of miRs in diagnostics and therapeutics.