Objectives:Glioblastoma(GBM)is a prevalent malignant brain tumor prone to drug resistance.We previously found a strong correlation between SH3 domain GRB2-like endophilin B1(SH3GLB1)and superoxide dismutase 2(SOD2),wh...Objectives:Glioblastoma(GBM)is a prevalent malignant brain tumor prone to drug resistance.We previously found a strong correlation between SH3 domain GRB2-like endophilin B1(SH3GLB1)and superoxide dismutase 2(SOD2),which converts O_(2) to hydrogen peroxide(H_(2)O_(2)).Prior studies show that H_(2)O_(2) redox signaling is vital for physiological processes and can drive tumor progression.Therefore,we aim to define how H_(2)O_(2) signaling regulates SH3GLB1 and AKT(protein kinase B)pathways in GBM and to assess whether modulating H_(2)O_(2) reverses temozolomide(TMZ)resistance.Methods:We used cultured cells and pharmacological inhibitors and activators to confirm the significance of H_(2)O_(2) signaling.GBM cells were used to verify the role of H_(2)O_(2) signaling in cell state transitions and animal experiments identified optimal treatment strategies.Results:We found that SOD2 acts as an upstream regulator of SH3GLB1.When SOD inhibitors and TMZ were combined,cells showed reduced SH3GLB1 and autophagy levels.SH3GLB1 was found to be regulated by H_(2)O_(2) via AKT signaling using redox homeostasis-regulating experiments.Although treatment-induced changes in mitochondrial H_(2)O_(2) levels mirrored those in the cytosol,parental and resistant cells exhibited divergent fates,highlighting cell-fate plasticity.TMZ combined with a redox modulator reduced resistant tumor cell growth(about 2/3 reduction of tumor size;p<0.05)and suppressed SH3GLB1 and autophagy levels in animal models.The TMZ-induced increase in SH3GLB1 expression was reversed by HgCl2,which inhibited the aquaporin-9/AKT signaling.Conclusion:Overall,these findings underscore the importance of H_(2)O_(2)-SH3GLB1 signaling in GBM and may inform future therapeutic strategies for overcoming TMZ resistance.展开更多
基金supported by research grants from the Ministry of Science and Technology(MOST 108-2314-B-400-026 and 109-2013-B-400-036)National Science and Technology Council(NSTC 112-2320-B-214-010 and 113-2320-B-214-002)+1 种基金I-Shou University(ISU-112-01-12A,ISU112-S-02 and ISU114-S-04)National Health Research Institutes,Taiwan(CA-111-PP-19).
文摘Objectives:Glioblastoma(GBM)is a prevalent malignant brain tumor prone to drug resistance.We previously found a strong correlation between SH3 domain GRB2-like endophilin B1(SH3GLB1)and superoxide dismutase 2(SOD2),which converts O_(2) to hydrogen peroxide(H_(2)O_(2)).Prior studies show that H_(2)O_(2) redox signaling is vital for physiological processes and can drive tumor progression.Therefore,we aim to define how H_(2)O_(2) signaling regulates SH3GLB1 and AKT(protein kinase B)pathways in GBM and to assess whether modulating H_(2)O_(2) reverses temozolomide(TMZ)resistance.Methods:We used cultured cells and pharmacological inhibitors and activators to confirm the significance of H_(2)O_(2) signaling.GBM cells were used to verify the role of H_(2)O_(2) signaling in cell state transitions and animal experiments identified optimal treatment strategies.Results:We found that SOD2 acts as an upstream regulator of SH3GLB1.When SOD inhibitors and TMZ were combined,cells showed reduced SH3GLB1 and autophagy levels.SH3GLB1 was found to be regulated by H_(2)O_(2) via AKT signaling using redox homeostasis-regulating experiments.Although treatment-induced changes in mitochondrial H_(2)O_(2) levels mirrored those in the cytosol,parental and resistant cells exhibited divergent fates,highlighting cell-fate plasticity.TMZ combined with a redox modulator reduced resistant tumor cell growth(about 2/3 reduction of tumor size;p<0.05)and suppressed SH3GLB1 and autophagy levels in animal models.The TMZ-induced increase in SH3GLB1 expression was reversed by HgCl2,which inhibited the aquaporin-9/AKT signaling.Conclusion:Overall,these findings underscore the importance of H_(2)O_(2)-SH3GLB1 signaling in GBM and may inform future therapeutic strategies for overcoming TMZ resistance.
