Accumulating evidence have demonstrated that cytokines are enriched in tumor-derived extracellular vesicles (EVs) and widely involved in tumorigenesis of various types of carcinomas, including colorectal cancer (CRC). Nevertheless, the functions of cytokines in EVs secreted from colorectal cancer cells remain largely unknown. In the present study, we found that TNF-α was elevated in EVs from CRC patient serum samples and CRC cell lines, of which the expression was associated with aggressive features of colorectal cancer. EV TNF-α secretion is dependent on synaptosome-associated protein 23 (SNAP23). Functional experiments revealed that EV TNF-α promotes CRC cell metastasis via the NF-κB pathway by targeting SNAP23. Mechanistically, SNAP23 was transcriptionally upregulated by EV TNF-α/NF-κB axis to enhance the expression of laminin subunit beta-3 (LAMB3), thereby activating the PI3K/AKT signaling pathway and consequently facilitate CRC progression. Based on our findings, we could conclude that EV TNF-α plays an oncogenic role in CRC progression through SNAP23, which in turn promotes EV TNF-α secretion, suggesting that EV TNF-α/SNAP23 axis may serve as a diagnostic biomarker and potential therapeutic target for CRC.
Keywords: Colorectal cancer; Extracellular vesicles; Metastasis; SNAP23; TNF-α.
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