The 8-oxoguanine DNA glycosylase-synaptotagmin 7 pathway increases extracellular vesicle release and promotes tumour metastasis during oxidative stress

Reactive oxygen species (ROS)-induced oxidative DNA damages have been considered the main cause of mutations in genes, which are highly related to carcinogenesis and tumour progression. Extracellular vesicles play an important role in cancer metastasis. However, the precise role of DNA oxidative damage in extracellular vesicles (EVs)-mediated cancer cell migration and invasion remains unclear. Here, we reveal that ROS-mediated DNA oxidative damage signalling promotes tumour metastasis through increasing EVs release. Mechanistically, 8-oxoguanine DNA glycosylase (OGG1) recognises and binds to its substrate 8-oxo-7,8-dihydroguanine (8-oxoG), recruiting NF-κB to the synaptotagmin 7 (SYT7) promoter and thereby triggering SYT7 transcription. The upregulation of SYT7 expression leads to increased release of E-cadherin-loaded EVs, which depletes intracellular E-cadherin, thereby inducing epithelial-mesenchymal transition (EMT). Notably, Th5487, the inhibitor of DNA binding activity of OGG1, blocks the recognition and transmission of oxidative signals, alleviates SYT7 expression and suppresses EVs release, thereby preventing tumour progression in vitro and in vivo. Collectively, our study illuminates the significance of 8-oxoG/OGG1/SYT7 axis-driven EVs release in oxidative stress-induced tumour metastasis. These findings provide a deeper understanding of the molecular basis of cancer progression and offer potential avenues for therapeutic intervention.