Extracellular DNA ecology in EBV-associated nasopharyngeal carcinoma

Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) contains several overlapping DNA pools, including viral DNA, tumor-derived nuclear DNA, mitochondrial DNA (mtDNA), neutrophil extracellular trap (NET) chromatin, and DNA released during treatment. These materials have usually been studied separately—as biomarkers, danger signals, or treatment-associated DNA species. We use the term extracellular DNA (exDNA) ecology to connect DNA source and molecular state with carrier, compartment, recipient cell, sensing route, clearance, and time. NPC studies provide several mechanistic anchors. Radiotherapy-associated mitochondrial injury can activate cGAS–STING and support type I interferon and CD8+ T-cell immunity, whereas mtDNA sensing in chemotherapy-induced senescent NPC cells can drive an NF-κB–IL-35 program that suppresses natural killer cells. Gemcitabine–cisplatin-generated DNA fragments can coordinate tumor-cell STING with B-cell TLR9, and EBV-derived BRRF2-positive extracellular vesicles can reduce macrophage cGAS competence. Several of these studies, however, map intracellular DNA generation or mitochondrial-to-cytosolic release without demonstrating extracellular transit. We therefore treat those events as upstream inputs to a possible extracellular route. An acute-to-persistent shift is proposed here as a testable working model, not as an established longitudinal sequence. Carrier state and recipient-cell identity may add information beyond DNA concentration alone. For clinical translation, plasma EBV DNA remains the most mature measurement, and early clearance after induction chemotherapy provides a practical setting in which molecular-state and immune-context readouts can be tested prospectively.