Exosomal long non-coding RNAs in human malignancies: biological functions and clinical applications

Exosomes, with a diameter ranging from 30 to 150 nm, are a subset of extracellular vesicles, enclosed by a lipid bilayer membrane, and released by various cell types. The biological function of exosomes depends on their bioactive cargo, which includes lipids, proteins, and non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs). Growing evidence suggests that exosomal lncRNAs play critical roles in cancer progression; they appear to be widely dysregulated in various cancer types, functioning as either oncogenes or tumor suppressors. However, their precise biological functions in cancer progression remain largely unclear. Given this, elucidating their impacts may facilitate a more comprehensive understanding of targeted cancer therapy. This review summarizes current research on the biological roles of exosomal lncRNAs in progression. We address how they influence essential oncogenic processes, including cell proliferation, angiogenesis, tumor immunity, metastasis, and drug resistance in various cancer types. Furthermore, we review the potential clinical applications of exosomal lncRNAs as therapeutic targets in human cancers as well as diagnostic and prognostic biomarkers. We also discuss the interactions between exosomal lncRNAs and other ncRNAs. Finally, we highlight the substantial translational potential of exosomal lncRNAs in enhancing cancer management by pointing out recent advances and persisting challenges.