Abstract

Glioblastoma is the most lethal intracranial malignant tumor, for which the five-year overall survival rate is approximately 5%. Here we explored the therapeutic combination of vitamin C and plasma-conditioned medium on glioblastoma cells in culture and as subcutaneous or intracranial xenografts in mice. The combination treatment reduced cell viability and proliferation while promoting apoptosis , and the effects were significantly stronger than with either treatment on its own. Similar results were obtained in the two xenograft models. Vitamin C appeared to upregulate aquaporin-3 and enhance the uptake of extracellular H 2 O 2 , while the combination treatment increased intracellular levels of reactive oxygen species including H 2 O 2 and activated the JNK signaling pathway . The cytotoxic effects of the combination treatment were partially reversed by the specific JNK signaling inhibitor SP600125 . Our results suggest that the combination of vitamin C and plasma-conditioned medium has therapeutic potential against glioblastoma, and they provide mechanistic insights that may help investigate this and other potential therapies in greater depth.