Deep sequencing and functional annotation reveal miRNAs implicated in the cell senescence phenotype

In cell senescence, cultured cells cease proliferating and acquire aberrant gene expression patterns. MicroRNAs (miRNAs) modulate gene expression through translational repression or mRNA degradation, and have been implicated in senescence. We have used deep sequencing to carry out a comprehensive survey of miRNA expression and its involvement in cell senescence. Informatic analysis of small RNA sequence datasets from young and senescent IMR90 human fibroblasts identifies many known miRNAs, and a small number of novel miRNAs, that are regulated (either up or down) with cell senescence. Comparison with mRNA expression profiles revealed potential mRNA targets of the senescence-regulated miRNAs. The target mRNAs are enriched for genes involved in biological processes associated with cell senescence. This result greatly extends existing information on the role of miRNAs in cell senescence, and is consistent with miRNAs having a causal role in the process. Overall design: Comprehensive survey of miRNA from young and senescent IMR90 fibroblasts using deep sequencing