Identification of Oncogene-Induced Senescence-Associated MicroRNAs.

Cellular senescence, a state of permanent cell cycle arrest, recapitulates the aging process at the cellular level. It can be triggered by intrinsic or extrinsic factors including telomere shortening (replicative senescence) and in response to various types of stresses such as oncogenic stress (oncogene-induced senescence, OIS). Senescence has been detected in vitro and in premalignant lesions in mice and humans expressing mutant oncogenes. MicroRNAs (miRNAs) are short noncoding RNAs that regulate gene expression at the posttranscriptional level, and have been involved in both replicative senescence and OIS. Several methods have been used to identify miRNAs and compare their expression in normal versus oncogene-induced senescent cells, as well as to analyze their role and their targets in senescence. Here, we describe several methods that can be employed to identify miRNAs in cells undergoing OIS, including miRNA-sequencing, RT-qPCR-based detection and quantification of miRNAs and Nanostring miRNA analysis (nCounter miRNA Expression Assay). Moreover, we perform a meta-analysis of studies employing the above methodologies, pinpoint miRNAs with consistent expression changes across senescence models, and predict their target genes and the pathways in which they partake.