AB017. NFκB1 regulates FDX1 to facilitate elesclomol-induced cuproptosis against glioblastoma.

BACKGROUND: Ferredoxin 1 (FDX1) plays key roles in promoting elesclomol-induced cuproptosis against cancer, whether it has the potential to be a new therapeutic strategy against glioblastoma has not yet been clarified. METHODS: Glioblastoma cells were treated with elesclomol (20 nM/L) and copper chloride (2 µM/L), and then cell proliferation, migration, and invasion were evaluated by CCK-8, clonogenic and transwell assay. Western blot was performed to detect the expression of cuproptosis-relating proteins FDX1, lipoylated dihydrolipoamide S-acetyltransferase (DLAT), copper transport ATPase (ATP7A), heat shock protein 70 (HSP70), apoptotic markers B cell lymphoma-2 (BCL-2) associated X protein (Bax), and BCL-2, as well as the pan-apoptotic/death markers gasdermin D (GSDMD), solute carrier family 7 member 11 (SLC7A11). The effects of knockdown and overexpression of FDX1 on cell proliferation, migration, and invasion were observed. Bioinformatic analysis was performed to predict the corresponding transcription factors regulating FDX1 expression, and verified by dual luciferase assay. The regulatory relationship between FDX1 and its transcription factors was verified by rescue experiment and further evaluated in vivo. RESULTS: Elesclomol had obvious inhibitory effects on the proliferation, migration, and invasion capacities of tumor cells in a dose-dependent manner. When combined with copper chloride, the inhibitory effects on tumor cells were significantly higher both in vitro and in vivo. FDX1 expression was negatively correlated with overall survival of patients. Nuclear factor κ-light-chain enhancer of activated B cell 1 (NFκB1) was the transcription factor of FDX1 verified by dual luciferase assay. Both FDX1 and NFκB1 were highly expressed in glioblastoma. Knockdown of FDX1 or NFκB1 down-regulated proliferation, migration, and invasion abilities of tumor cells, and increased after FDX1 overexpression. FDX1 expression decreased correspondingly after NFκB1 knockdown. Up-regulation of FDX1 promoted elesclomol-induced cuproptosis against glioblastoma both in vitro and in vivo. FDX1 knockdown can reverse the inhibitory effect of elesclomol on tumor cells. CONCLUSIONS: Elesclomol inhibits glioblastoma development via inducing cuproptosis, regulated by NFκB1/FDX1 axis.

Glioblastoma stem cell-derived exosomal miR-374b-3p promotes tumor angiogenesis and progression through inducing M2 macrophages polarization.

Glioblastoma stem cells (GSCs) reside in hypoxic periarteriolar niches of glioblastoma micro-environment, however, the crosstalk of GSCs with macrophages on regulating tumor angiogenesis and progression are not fully elucidated. GSCs-derived exosomes (GSCs-exos) are essential mediators during tumor immune-microenvironment remodeling initiated by GSCs, resulting in M2 polarization of tumor-associated macrophages (TAMs) as we reported previously. Our data disclosed aberrant upregulation of miR-374b-3p in both clinical glioblastoma specimens and human cell lines of GSCs. MiR-374b-3p level was high in GSCs-exos and can be internalized by macrophages. Mechanistically, GSCs exosomal miR-374b-3p induced M2 polarization of macrophages by downregulating phosphatase and tensin expression, thereby promoting migration and tube formation of vascular endothelial cells after coculture with M2 macrophages. Cumulatively, these data indicated that GSCs exosomal miR-374b-3p can enhance tumor angiogenesis by inducing M2 polarization of macrophages, as well as promote malignant progression of glioblastoma. Targeting exosomal miR-374b-3p may serve as a potential target against glioblastoma.