Extracellular vesicle long non-coding RNAs and circular RNAs: Biology, functions and applications in cancer

Extracellular vesicles (EVs) have been recognized as vital mediators of intercellular communication that allow horizontal information exchange among tumor cells as well as reciprocal cross-talk between tumor and stromal cells. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are selectively packaged into EVs then transferred to proximal and distal recipient cells, inducing profound phenotypic changes. Recently, there has been substantial progress in understanding the essential roles of EV-associated lncRNAs and circRNAs in cancer initiation and progression. The distinctive properties of these ncRNAs carried by EVs, including their tissue-specific expression, relative stability, targeted delivery and widespread presence in various biofluids, has also prompted the exploration of their potential in liquid biopsy and therapeutic usage. Herein, we summarized the biology, characteristics and functions of EV-associated lncRNAs and circRNAs, highlighting their vital roles in hallmarks of cancer and their prospective applications in cancer management. The challenges unresolved in this field were additionally pointed out to guide future studies.