Induced Ferroptosis to Inhibit Glioma Cells and was Associated with Increased Oxidative Stress.

Background: Glioma, a malignant brain tumour, poses a significant threat to human life and well-being. Identifying new treatment targets is crucial. This study aimed to explore the impact of (BRCA1 interacting helicase 1) on glioma cell ferroptosis and its underlying mechanisms.

Methods: We utilized GEPIA (Gene Expression Profiling Interactive Analysis) to predict the expression of in glioma. The expression of was evaluated in normal brain glial cell lines (HEB) as well as two glioblastoma (GBM) cell lines (U87 and U251) using qRT-PCR (quantitative RT-PCR) and Western blot analyses. U251 cells were specifically chosen to investigate the impact of down-regulation and treatment with erastin (a ferroptosis activator) on cell viability and proliferation. In U251 cells, si- was administered in combination with the necroptosis inhibitor Necrostain-1 (Nec-1), apoptosis inhibitor Z-VAD-FMK (carbobenzoxy-valyl-alanyl-aspartyl- [O-methyl]-fluoromethylketone), autophagy inhibitor CQ (Chloroquine), pyroptosis inhibitor VX765 (Belnacasan), or ferroptosis inhibitor Fer-1 (ferrostain-1), as well as erastin+Fer-1, to determine the mode of programmed cell death using the CCK-8 (Cell counting kit-8) assay. Malondialdehyde (MDA) and glutathione (GSH) levels were measured using ELISA (Enzyme linked immunosorbent assay). Intracellular Fe content was detected using a commercial reagent kit. (Glutathione peroxidase 4) levels were measured using Western blot analysis. The relationship between and (Solute Carrier Family 7 Member 11) was verified by co-IP (co-immunoprecipitation) experiments. The level of and (Solute Carrier Family 3 Member 2) was analyzed through qRT-PCR and Western blot analyses. A rescue experiment was conducted to observe the effects of overexpression on si--treated U251 cells.

Results: The GEPIA database predicted that the expression level of was increased in glioma. The expression level of was higher in U251 cells compared to HEB and U87 cells ( < 0.05). Both down-regulation of and treatment with erastin resulted in inhibited cell viability and proliferation in U251 cells ( < 0.05). The mode of programmed cell death in si--treated U251 cells was ferroptosis. Following si- transfection or erastin treatment, there was an increase in the levels of MDA and intracellular Fe content, as well as a decrease in the levels of GSH, , and ( < 0.05). However, these alterations observed in the si- group were reversed by Fer-1 treatment ( < 0.05). The co-IP results demonstrated that BRIP1 and SLC7A11 were able to bind to each other. Up-regulation of reversed the reduction in cell viability, the increase in MDA, the reduction in GSH, the increase in Fe content, and the down-regulation of in si--treated U251 cells ( < 0.05).

Conclusion: In this study, we found that down-regulation of could inhibit cell viability and proliferation in glioma cells through the induction of ferroptosis. This process was associated with increased oxidative stress, which was mediated by the down-regulation of S ( (Cysteine/glutamate transporter)) expression.