[Circular ribonucleic acid and its tumor-biological relevance].

One of the most remarkable chapters in recent years' research of molecular biology is the quest for non-coding ribonucleic acids (RNAs). Circular RNAs form a distinct group within non-coding RNAs and their significance is being discovered only now. These uncommonly stable molecules take part in the regulation of gene expression by various mechanisms, by decoying microRNAs or by acting upon the translational machinery. The altered expression of circular RNAs was described in different types of cancers, and considering their stability, circular RNAs could be exploited as future biomarkers and even as molecular targets. In this synopsis, the authors present the biological characteristics and the tumor-biological relevance of circular RNAs. Orv Hetil. 2020; 161(11): 403-412.