MicroRNAs in cancer diagnosis and therapy: from bench to bedside.

Epigenetic changes, such as DNA methylation and histone modifications, regulate gene expression. It is speculated that investigating the fundamental epigenetic mechanisms and their gene regulation will promote a better understanding of cancer development. The idea of epigenetic modification has been extended to microRNAs (miRs). MiRs are single-stranded RNA molecules, about 19-25 ribonucleotides in length, which regulate gene expression post-transcriptionally and can act as tumor suppressors or oncogenes. We review the most recent findings related to their mechanisms of action, the modification of miR expression, and their relationship to cancer. We also discuss the potential application of miRs in the clinical setting, such as for biomarkers and therapy.