Exosomal long noncoding RNAs and microRNAs in colorectal cancer.

Abstract

This review focuses on the multifaceted roles of exosomal noncoding RNAs (ncRNAs) in colorectal cancer (CRC), utilizing the provided document as the primary source of information. Exosomes, nanoscale vesicles ranging from 30 to 150 nm, act as crucial mediators of intercellular communication, encapsulating bioactive molecules such as microRNAs (miRNAs) and long ncRNAs (lncRNAs). The biogenesis of exosomes involves the endocytic pathway, including the formation of multivesicular bodies and subsequent release of intraluminal vesicles into the extracellular space. This process is regulated by the endosomal sorting complex required for transport (ESCRT) machinery and other ESCRT-independent mechanisms, as well as RNA-binding proteins (RBPs) that selectively package ncRNAs. MiRNAs, shorter single-stranded RNA molecules, regulate gene expression post-transcriptionally by binding to target mRNAs, leading to translational repression or mRNA degradation. LncRNAs, longer RNA molecules, are involved in chromatin remodeling and transcriptional regulation and act as competing endogenous RNAs that modulate miRNA availability. Exosomal ncRNAs play a crucial role in tumorigenesis, where certain miRNAs promote proliferation while others act as tumor suppressors. Furthermore, these ncRNAs are central to the epithelial-mesenchymal transition, a critical process that facilitates metastasis. They also play a role in chemoresistance by modulating drug metabolism and apoptotic pathways. Exosomal ncRNAs also show promise as diagnostic and prognostic biomarkers due to their presence in body fluids and their association with disease progression. Moreover, they hold potential as therapeutic agents through RNA-based therapeutics and exosome-based drug delivery. The challenges involve standardizing exosome research, elucidating the underlying mechanisms, and ensuring successful clinical translation.