Presence and prospects of exosomal circRNAs in cancer (Review).

Exosomes are nanoscale extracellular vesicles secreted by parent cells and they are present in most bodily fluids, are able to carry active substances through intercellular transport and mediate communication between different cells, in particular those active in cancer. Circular RNAs (circRNAs) are novel noncoding RNAs expressed in most eukaryotic cells and are involved in various physiological and pathological processes, particularly in the occurrence and progression of cancer. Numerous studies have indicated a close relationship between circRNAs and exosomes.