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 7

TRAF3 impedes FAO and induces lipid peroxidation in GBM cells through ubiquitination of ECH1.

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TRAF3 impedes FAO and induces lipid peroxidation in GBM cells through ub...
(A) Relative content of SFAs, MUFAs, and PUFAs in GBM0709 cells expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R (n = 3). (B) Biosynthetic analysis of lipid species in GBM0709 cells expressing TRAF3 compared with the control group. (C) Relative content of SFAs, MUFAs, and PUFAs in CL in GBM0709 cells expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R (n = 3). (D) OCR time series in GBM0709 cells expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R. (E and F) Quantification of basal respiration and maximum respiration (E) and ATP production (F) in GBM0709 cells. (G) Quantification of acetyl-CoA levels in GBM0709 cells. In D–G, Data are expressed as the mean ± SD of 3 or 4 independent experiments. (H and I) Flow cytometric analysis of CellROX (H) and MitoSOX (I) staining in GBM0709 cells expressing TRAF3, TRAF3+ECH1- WT, or TRAF3+ECH1-K214R (n = 3). (J) GSH/GSSG ratios in GBM0709 cells expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R (n = 3). (K) MDA levels in GBM0709 cells expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R (n = 3). (L) Cell viability of GBM0709 and GBM0108 cells stably expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R was evaluated by CCK8, normalized to the control (n = 4). (M and N) GBM0709 cells stably expressing TRAF3, TRAF3+ECH1-WT, or TRAF3+ECH1-K214R were i.c. injected into nude mice. H&E-stained sections show representative tumor xenografts (M). Mouse tumor tissues were stained for ECH1, Ki-67, 8-oxoG, and 4-HNE, respectively (M). Scale bars: 100 μm. Tumor volumes were calculated (n = 5) (N). (O) Survival of GBM0709 GBM tumor–bearing mice (n = 5 mice, Kaplan-Meier model). Statistical significance was determined by 1-way ANOVA with Tukey’s post hoc test (A, C, E–L, and N) or log-rank test (O). Data represent the mean ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001.