Hypoxia-induced one-carbon metabolic reprogramming in glioma stem-like cells.

Glioma stem cells (GSCs) in the hypoxic niches contribute to tumor initiation, progression, and recurrence in glioblastoma (GBM). Metabolic pathways are altered in GSCs under hypoxia, but the mechanism underlying the altered one-carbon metabolism in GSCs by hypoxia is largely unknown. Here, we report that hypoxia induces down-regulation of DHFR as well as up-regulation of MAT2A in GBM tumorsphere cells, and confers them the ability of cell proliferation that is independent of exogenous folate. Importantly, short-term inhibition of the methionine cycle or exposure to the MAT2A inhibitor is sufficient to cripple the tumor-initiating capability of GBM tumorsphere cells. Therefore, we present a novel perspective on how hypoxia alters the pattern of one-carbon metabolism in GBM tumorsphere cells and provide evidence that restriction of methionine intake or targeting MAT2A inhibits the tumorigenicity of GBM tumorsphere cells.