Tumor-derived Extracellular Vesicles-mediated Oxidative Stress Transfer Activates Glycometabolic Reprogramming of CAFs

Background Stressed by the adverse conditions of the tumor microenvironment (TME), hyperproliferation of tumor cells is accompanied by high production of reactive oxygen species (ROS). Tumor-derived extracellular vesicles (TEVs) exert a variety of biological functions in the interaction between the tumor cells and cancer-associated fibroblasts (CAFs). However, the intercellular transmission of ROS and its role in tumor-stroma communication remain unclear. Method The human gingival fibroblasts (HGFs), paracancerous normal fibroblasts (PNFs) and CAFs were isolated from the healthy gingival tissues of volunteers and six patients with OSCC. HGFs were treated with CAL27/SCC25 TEVs. In vitro , we assessed the level of autophagy and glycometabolism in PNFs/CAFs and HGFs/TEVs-treated HGFs by immunofluorescence and Western blot. Blockage or activation of autophagy was employed to investigate its effects on glycometabolism. Flow cytometry was used to detect whether TEVs play a crucial role in inducing fibroblast autophagy and glycolysis through ROS transfer. In vivo , xenograft models were established to validated the effect of TEVs. Results CAFs exhibited higher level in autophagy compared with PNFs. Treatment with autophagy inhibitors diminished autophagy-dependent glycometabolic reprogramming induced by TEVs, whereas activation of autophagy enhanced glycolysis in CAFs. Furthermore, ROS transferred by TEVs was confirmed to drive glycometabolic reprogramming through both autophagy-dependent mechanisms and the HIF-1α/PFKFB3 axis. In vivo , TEVs consistently promoted autophagy and glycometabolic reprogramming. Conclusion TEVs-induced intercellular transmission of ROS and the regulatory role of ROS-mediated autophagy in the glycometabolic reprogramming of CAFs, providing a novel rationale for the oxidative stress transfer model in tumor-stroma crosstalk.