Cancer Cell‐Derived Large Extracellular Vesicles Promote Venous Thromboembolism by Activating NETosis Through Delivering CYBA

Abstract Venous thromboembolism (VTE) is the second‐leading cause of cancer‐associated mortality. Neutrophil extracellular trap formation (i.e., NETosis) is a crucial process in forming VTE in cancer patients. Nevertheless, how cancer cells contribute to NETosis remains unclear. This study investigated the potential activation effects of cancer cell‐derived extracellular vesicles (CC‐EVs) on neutrophils. Both small and large EVs (sEVs and lEVs) released from cancer cells are found to significantly induce NETosis in neutrophil‐like HL‐60 (dHL‐60) cells. Following an in‐depth exploration of EV‐induced NETosis, the specific molecular pathways involved in this biological process are elucidated. CYBA enriched in CC‐lEVs is delivered to dHL‐60, leading to a rapid increase in intracellular ROS levels and upregulation of citH3 expression. This cascade resulted in decondensed chromatin release and subsequent NETosis along with elevated MPO‐DNA levels. Injection of CC‐lEVs into mice caused more pronounced VTE, which is accompanied by increased peripheral blood levels of the MPO‐DNA and thrombin‐antithrombin complex. Inhibiting CYBA expression or ROS generation prevented NETosis in vitro and significantly reduced VTE in vivo. In conclusion, CC‐lEVs induce NETosis through the CYBA‐ROS‐citH3 pathway and increase VTE risk. Targeting CYBA expression or ROS production can provide novel strategies for preventing and treating VTE in high‐risk cancer patients.