Competing Endogenous RNA (ceRNA): a New Class of RNA Working as Mirna Sponges

MicroRNAs (miRNAs) are widely known as a class of non-coding RNA (ncRNA), which regulate gene expression, largely at the post-transcriptional level, but rarely also at the transcription level. During the last few years, a new class of ncRNA has been discovered, which counteracts the repressive activity of miRNA, by sequestering miRNA within a cell. These novel ncRNA molecules have been variously described as 'miRNA sponges/decoys', 'target mimics' or 'competing endogenous RNA'. Several reports of the occurrence of these ceRNAs and their role in regulating gene expression were published recently, which are briefly described in this article. These discoveries will keep scientists busy for many years to generate new information.