Splice and dice: intronic micrornas, splicing and cancer

Abstract

Introns span only a quarter of the human genome, yet they host around 60% of all known microRNAs. Emerging evidence indicates the adaptive advantage of microRNAs residing within introns is attributed to their complex co-regulation with transcription and alternative splicing of their host genes. Intronic microRNAs are often co-expressed with their host genes, thereby provid-ing functional synergism or antagonism that is exploited or decoupled in cancer. Additionally, in-tronic microRNA biogenesis and the alternative splicing of host transcript are co-regulated and in-tertwined. The importance of intronic microRNAs is under-recognized in relation to the pathogen-esis of cancer.