Circular versus linear RNA topology: different modes of RNA-RNA interactions in vitro and in human cells.

Circular RNA is progressively reported to occur in various species including mammals where it is thought to be involved in the post-transcriptional regulation of gene expression, partly via interactions with microRNA. Here, we asked whether the circular topology causes functional differences to linear forms when interacting with short RNA strands and in human cells. Kinetic studies with human bladder cancer-derived synthetic circular RNA versus linear transcripts, respectively, with short oligoribonucleotides showed similar association rates for both topologies.