DMMC Course: EPIGENETICS: FROM MECHANISMS TO MEDICINES

1050-1140 Monday 25 June 2007. O’Reilly Hall, University College Dublin.

miRNA
Prof Orla Sheils (Trinity College Dublin)

MicroRNAs are regulatory, non-coding RNAs about 22 nucleotides in length. To date several hundred have been identified in humans. Although they are small molecules, microRNAs can have profound effects because they regulate a variety of genes. They have been shown to have a significant role in carcinogenesis. Moreover, data suggests characteristic signatures of miRNA expression associate with different tumour types. The expression of miRNAs appears to be highly regulated according to the cell's developmental lineage and stage. Indeed some reports suggest the expression pattern of miRNAs defines a cancer type better than expression data from 16,000 mRNAs. These observations could improve the diagnosis and prognostication of cancers, allowing better-informed choices for treatment. They also promise to shed light on the regulatory circuits that malfunction during tumourigenesis increasing our understanding of disease pathobiology.