RESUMO
The mutation of isocitrate dehydrogenase (IDH)1 (R132H) and IDH2 (R172K) and the induction of hypoxia in various solid tumors results in alterations in metabolic profiles, including the production of the d or lforms of 2hydroxyglutarate (2HG) from αketoglutarate in aerobic metabolism in the tricarboxylic acid (TCA) cycle. However, it is unclear whether the oncometabolite d2HG increases angiogenesis in endothelial cells. Therefore, in this study, we analyzed the levels of various metabolites, including d2HG, under hypoxic conditions and in IDH2R172K mutant breast cancer cells by mass spectrometry. We then further evaluated the effects of this metabolite on angiogenesis in breast cancer cells. The results revealed that treatment with d2HG increased the levels of secreted vascular endothelial growth factor (VEGF) in cancer cells and enhanced endothelial cell proliferation in a concentrationdependent manner. Wound healing and cell migration (examined by Transwell assay) were significantly increased by d2HG to a level similar to that induced by VEGF. Tube formation was significantly stimulated by d2HG, and chick chorioallantoic membrane angiogenesis was also enhanced by d2HG. d2HG activated VEGF receptor (VEGFR)2 and VEGFR2 downstream signaling, extracellular signalregulated kinase 1/2, focal adhesion kinase, AKT and matrix metalloproteinase (MMP)2. Taken together, the findings of this study suggested that d2HG induced angiogenic activity via VEGFR2 signaling and increased MMP2 activity.