Mesenchymal Colorectal Cancers Secrete Vesicles With Unique Cargo That Can Be Used for Liquid Biopsy Based Diagnostics

Tumour-derived extracellular vesicles (TEVs) play a crucial role in cancer progression, metastasis and therapy resistance but their distinct profiles across different cancer stages and molecular subtypes remain underexplored. This study initially analysed TEVs from all CMS subtypes in colorectal cancer (CRC) cells and continued focusing on the epithelial (CMS2) and mesenchymal (CMS4) subtypes using six cell lines and clinical samples. Investigation of the cargo of vesicles secreted by the two subtypes revealed significant differences in mRNA, miRNA, and protein profiles between the two subtypes. Notably, CMS2 predominantly secreted smaller, Tetraspanin-8 (TSPAN8) enriched EVs, while CMS4 produced both larger and smaller EVs, enriched in TSPAN4. This underscores the complexity of vesicle heterogeneity between these subtypes. Additionally, we assessed miRNA profiles from plasma-derived bulk TEVs in CRC patients. Our integrative analysis identified a subtype-specific miRNA signature, indicating that TEVs from CMS2 and CMS4 cells can be detected in circulation and may serve as potential diagnostic tool for CRC.