Abstract 3270: SH3GLB1 is involved with hydrogen peroxide/akt signaling in glioblastoma multiforme cells

Abstract

Abstract Glioblastoma (GBM), a malignant brain tumor, has poor survival outcomes due to recurrence or drug resistance. In our previous studies, it was found that superoxide dismutase 2 (SOD2) was associated with temozolomide (TMZ) resistance. Moreover, SOD2 can convert O2 •− to H2O2, and H2O2 redox signaling is vital for physiological reactions and promotes tumor progression. We used cell lines, patient primary cells and pharmacological inhibitors/activators to confirm the significance of H2O2 signaling. We used the cultured cells to verify roles of H2O2 signaling in the plasticity of cell fate and did animal experiments to identify the optimal treatment strategy. In the present study, SOD2 was found to be the upstream mediator, and combining SOD inhibitor and TMZ, the cells showed reduced SH3GLB1 and autophagy levels. We then found that SH3GLB1 was regulated by H2O2 through AKT signaling using experiments of regulating redox homeostasis. The change of intracellular H2O2 levels in mitochondria following the treatments is similar to that in cytosol, however, the cell fate of parental or resistant cells was quite diverse. Notably, CCCP, a mitochondrial membrane potential disrupter, increased endogenous H2O2 production, and TMZ-increased SH3GLB1 levels can be reversed by HgCl2, reflecting the aquaporin function. In animal models, a combination of TMZ and 4-hydroxynonenal reduced growth of the SH3GLB1-knockdown resistant cells, along with suppressed autophagy levels. Our results characterizing the mechanism of H2O2-SH3GLB1 axis signaling in acquired TMZ resistance of GBM cells will provide new therapeutic strategies against the disease in the future. Citation Format: Chia-Hung Chien, Kwang-Yu Chang. SH3GLB1 is involved with hydrogen peroxide/akt signaling in glioblastoma multiforme cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3270.