2025/07/30 by Hsi-wen Yeh, Nicole L. DelGaudio, Beste Uygur +16 · 1 voice · 5 citations
Biochemistry, Genetics and Molecular Biology · #Cancer, Hypoxia, and Metabolism #Sulfur Compounds in Biology #Redox biology and oxidative stress
paper · doi:10.1158/2159-8290.cd-24-1556
Cancer cells require substantial metabolic adaptations to metastasize to distant organs, but the metabolites essential for successful colonization remain poorly defined. In this study, we used a mitochondrial metabolomics approach to compare primary and metastatic breast cancer cells. This analysis revealed accumulation of mitochondrial glutathione (GSH) during lung metastasis, driven by elevated expression of SLC25A39, a mitochondrial GSH transporter. Loss of SLC25A39 impairs metastatic colonization in genetic screens, cell line models, and patient-derived xenografts, without affecting primary tumor growth. Mitochondrial GSH import is specifically required during early colonization and functions independently of its canonical antioxidant role. CRISPR activation screens identified ATF4, a stress-induced transcription factor, as a bypass mechanism that restores metastatic potential in SLC25A39-deficient cells. Mechanistically, SLC25A39 is required for optimal ATF4 activation during metastasis and under hypoxia, linking mitochondrial GSH availability to integrated stress response signaling. These findings identify mitochondrial GSH as a necessary and limiting metabolite for metastatic progression. SIGNIFICANCE: Mitochondrial GSH import via SLC25A39 is essential for early metastatic colonization in breast cancer, linking metabolic adaptation to stress response signaling. Targeting this pathway may uncover a therapeutic vulnerability specific to metastasis without affecting primary tumor growth.