The Emerging Role of Extracellular Vesicle-Derived lncRNAs and circRNAs in Tumor and Mesenchymal Stem Cells: The Biological Functions and Potential for Clinical Application.

Extracellular vesicles (EVs) are released by nearly all types of cells, and they communicate between cells by transporting bioactive molecules, including proteins, DNA, RNA, and lipids. In recent years, RNA carried by EVs, particularly the long-chain non-coding RNA (lncRNA) and circular RNA (circRNA) subtypes, has garnered interest with respect to their role in controlling tumor progression. Among them, there are increasing reports that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) maintain a recently discovered function as transporters of lncRNAs and circRNAs. However, detailed molecular functions of lncRNAs and circRNAs contained in MSC-EVs are not presently summarized, and the efficacy of MSC-EVs as molecular carriers requires further elucidation. This review summarizes the biological characteristics of EVs and the common mechanisms of lncRNAs and circRNAs contained within them. The "double-edged sword" effect and related molecular mechanism of EV-derived lncRNAs (EV-lncRNAs) and circRNAs (EV-circRNAs) between differing tumor types and MSCs are highlighted. The potential of MSC-EVs in the field of tumor diagnosis and treatment is discussed to suggest new directions for the strategy of engineering MSC-EVs as anti-tumor drug carriers.