Exosomes loaded with metabolites: Roles in crosstalk between tumor cells and their microenvironment.

Exosomes, small endosome-derived vesicles, mediate intercellular crosstalk among cancer cells within the tumor microenvironment (TME), while metabolic reprogramming directly drives these phenotypic changes. Recently, the application of nanoparticle tracking analysis and mass spectrometry to exosome identification and metabolite detection has brought exosome-loaded metabolites in the TME into sharp research focus. In this study, we compared the exosomal metabolites derived from cancer versus normal cells, and elucidated how these differences modulate communication between tumor and stromal or immune cells. The differences in oncometabolites associated with tumors mainly include changes in fatty acids and amino acids. Tumor metabolic shifts reflected by exosomal amino-acids alterations center on glutamate metabolism and arginine biosynthesis. Tumor-associated alterations in exosomal fatty acids centered around the biosynthesis and metabolism of phosphatidylcholine and ceramide. Like nucleic acids and proteins, exosomal metabolites serve as non-invasive, efficient biomarkers for cancer detection.