Cancer-Derived Exosomes: A Cross-Cancer Comparative Analysis of Exosomal Proteins and MicroRNAs

Exosomes are small extracellular vesicles that mediate intercellular communication and, in cancer, carry cargo that both reflects the donor tumor cell and influences recipient cells within local and distant microenvironments. Exosomal proteins and microRNAs have been reported individually across many cancer types, but rarely compared on a common basis; in this review, previously reported molecules from eight cancer categories-blood, breast, colon, kidney, liver, lung, prostate, and stomach-were compiled from curated repositories and re-analyzed within a single functional framework. In total, 3643 exosomal proteins (523 hematologic, 3120 solid-tumor) and 627,225 miRNA-target pairs, derived from 350 unique microRNAs, were organized using Gene Ontology, KEGG, and PANTHER annotation. Across cancers, proteins converged on a reproducible core-signaling, transport, cytoskeletal organization, and extracellular interaction-dominated by binding, catalytic, and transporter functions localized to membrane, vesicle, and extracellular compartments. Comparisons between hematologic and solid malignancies revealed both shared cancer-associated functions and context-dependent patterns linked to tissue origin and disease ecology. Together, these findings indicate that integrated protein-and-microRNA profiling offers a useful framework for understanding tumor communication, refining cancer classification, and advancing biomarker discovery, while underscoring that harmonized workflows, independent validation, and mechanistic follow-up remain necessary before descriptive enrichment outputs can support clinically robust applications.