TRAF3 loss protects glioblastoma cells from lipid peroxidation and immune elimination via dysregulated lipid metabolism
Yu Zeng, … , Ye Song, Aidong Zhou
Yu Zeng, … , Ye Song, Aidong Zhou
Published February 11, 2025
Citation Information: J Clin Invest. 2025;135(7):e178550. https://doi.org/10.1172/JCI178550.
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Research Article Cell biology Metabolism

TRAF3 loss protects glioblastoma cells from lipid peroxidation and immune elimination via dysregulated lipid metabolism

Abstract

Glioblastoma (GBM) is a highly aggressive form of brain tumor characterized by dysregulated metabolism. Increased fatty acid oxidation (FAO) protects tumor cells from lipid peroxidation–induced cell death, although the precise mechanisms involved remain unclear. Here, we report that loss of TNF receptor–associated factor 3 (TRAF3) in GBM critically regulated lipid peroxidation and tumorigenesis by controlling the oxidation of polyunsaturated fatty acids (PUFAs). TRAF3 was frequently repressed in GBM due to promoter hypermethylation. TRAF3 interacted with enoyl-CoA hydratase 1 (ECH1), an enzyme that catalyzes the isomerization of unsaturated FAs (UFAs) and mediates K63-linked ubiquitination of ECH1 at Lys214. ECH1 ubiquitination impeded TOMM20-dependent mitochondrial translocation of ECH1, which otherwise promoted the oxidation of UFAs, preferentially the PUFAs, and limited lipid peroxidation. Overexpression of TRAF3 enhanced the sensitivity of GBM to ferroptosis and anti–programmed death–ligand 1 (anti–PD-L1) immunotherapy in mice. Thus, the TRAF3/ECH1 axis played a key role in the metabolism of PUFAs and was crucial for lipid peroxidation damage and immune elimination in GBM.

Authors

Yu Zeng, Liqian Zhao, Kunlin Zeng, Ziling Zhan, Zhengming Zhan, Shangbiao Li, Hongchao Zhan, Peng Chai, Cheng Xie, Shengfeng Ding, Yuxin Xie, Li Wang, Cuiying Li, Xiaoxia Chen, Daogang Guan, Enguang Bi, Jianyou Liao, Fan Deng, Xiaochun Bai, Ye Song, Aidong Zhou

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Figure 8

Overexpression of TRAF3 sensitizes GBM to erastin and anti–PD-L1 therapy.

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Overexpression of TRAF3 sensitizes GBM to erastin and anti–PD-L1 therapy...
(A) GBM0709 and GBM0108 cells expressing TRAF3 were treated with different concentration of erastin for 72 hours, and IC50 values for each cell line were calculated (mean ± SD, n = 4 independent experiments). (B and C) GBM0108 cells (5 × 105 cells/mouse) stably expressing TRAF3 were i.c. injected into nude mice. Mice were then i.p. injected with erastin (15 mg/kg/d) every other day. H&E-stained sections show representative tumor xenografts (B). The mouse tumor tissues were stained with TRAF3, 4-HNE, and cleaved caspase 3 (cCASP3), respectively (B). Scale bars: 100 μm. Tumor volumes were calculated (C) (mean ± SD, n = 5 mice for each group). *P < 0.05 and ***P < 0.001. (D) Survival of the mice (n = 5 mice for each group, Kaplan-Meier model). *P < 0.05 and **P < 0.01. (E) GBM0709 cells expressing TRAF3 were cocultured with activated CD8+ T cells for 48 hours with different E/T ratios (from 1:1 to 10:1), and cell viability was evaluated (mean ± SD, n = 3 independent experiments). *P < 0.05, **P < 0.01, and ***P < 0.001. (F) GBM0709 cells expressing TRAF3 were treated with ferrostatin (Fer) or DMSO and then cocultured with activated CD8+ T cells for 48 hours (E/T ratio = 3:1). The surviving and dead cells were stained by calcein-AM/PI. Representative images are shown. Scale bar: 100 μm. The percentage of PI+ cells was counted (mean ± SD, n = 5 randomly selected microscope fields). ***P < 0.001. (G–I) CT-2A cells stably expressing TRAF3 were i.c. injected into C57BL/6 mice. Mice were then i.p. injected twice with anti–PD-L1 mAb (200 μg/mouse/d) (G). H&E-stained sections show representative tumor xenografts. Tumor tissues were stained for TRAF3, GZMB, 4-HNE, and cleaved caspase 3, respectively (H). Scale bars: 100 μm. Tumor volumes were calculated (I) (mean ± SD, n = 5 mice for each group). **P < 0.01, ***P < 0.001. (J) Survival of the CT-2A GBM tumor–bearing mice (n = 5 mice for each group, Kaplan-Meier model). *P < 0.05 and **P < 0.01. Statistical analysis was performed using 1-way ANOVA with Tukey’s post hoc test (C, E, F, and I) or a log-rank test (D and J).