Posttranscriptional regulation of miRNAs in the DNA damage response.

DNA damage response is an elaborate process in which cells react to external or internal DNA damaging stress. An extensive network of signaling molecules, complexes, and pathways has been identified in the DNA damage response. Emerging evidence indicates that microRNAs (miRNAs) play essential roles in the DNA damage and repair pathways. While much effort has been to predict in silico and verify miRNA target genes, little is known about how miRNAs themselves respond to DNA damage. Here we discuss recent studies showing whether and how miRNAs are regulated in the DNA damage response. MiRNA expression involves transcription of miRNA genes and maturation of the primary transcripts. Therefore, miRNA levels might be regulated in both transcription dependent and independent manners. While the DNA damage response is known to protect against tumorigenesis in vivo, a deficient response could contribute to tumorigenesis through miRNAs.