Mir-9/mir-79 microRNA precursor family

The miR-9 microRNA precursor (homologous to miR-79), is a short non-coding RNA gene involved in gene regulation. miR-9 has been identified in Drosophila (MI0000129), mouse (MI0000720) and human (MI0000466) , and the related miR-79 in C. elegans (MI0000050) and Drosophila melanogaster (MI0000374). The mature ~21nt miRNAs are processed from hairpin precursor sequences represented here. miR-9 is processed from the 5' arm of its precursor, and miR-79 from the 3' arm. The bounds of the precursors are predicted based on conservation and base pairing and are not generally known. microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The mature products are thought to have regulatory roles through complementarity to mRNA.

microRNAs have been implicated in human cancer in a number of studies. Generally microRNA expression levels are reduced. It has been shown that human miR-9 expression levels are reduced in many breast cancer samples due to hypermethylation an epigenetic modification.