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Researchers knocked out the ferritin heavy chain (FTH) gene in medulloblastoma brain tumor cells and found that while cells survived under normal conditions by adapting their iron metabolism, they became highly vulnerable to iron-induced toxicity. FTH-deficient tumor cells died through multiple iron-dependent pathways when exposed to oxidative iron stress or vitamin C treatment, with this vulnerability being especially pronounced in mesenchymal-like cancer cells. In mouse models, loss of FTH impaired tumor growth and extended survival, establishing that inducing iron toxicity rather than iron deprivation represents a therapeutic opportunity.
Why it matters
This work identifies a new therapeutic strategy for medulloblastoma and potentially other cancers by targeting iron metabolism through ferritin disruption or manipulation of cellular iron levels. The findings suggest that treatments promoting iron toxicity, including readily available compounds like vitamin C, could selectively kill cancer cells with compromised iron buffering capacity.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Iron is essential for tumor proliferation and metabolic adaptation but becomes cytotoxic when unbuffered, creating a potential metabolic vulnerability. Ferritin, a conserved iron-storage complex, limits labile iron and establishes the upper threshold of iron tolerance in cancer cells. Here, we report the first ferritin heavy chain (FTH) knockout in a brain tumor model system. Although FTH loss was tolerated under basal conditions through adaptive remodeling of iron metabolism, it exposed profound vulnerabilities under iron stress. FTH deficiency lowered the threshold for iron toxicity, sensitizing medulloblastoma (MB) cells to both canonical ferroptosis and a mechanistically distinct iron-dependent cell death pathway. Oxidative iron stress impaired tumor growth and prolonged survival in orthotopic xenografts, whereas vitamin C-induced iron reduction triggered a selective, iron-dependent, but non-ferroptotic elimination of MB-like cells in tumor organoids. Notably, sensitivity to iron toxicity correlated strongly with cellular phenotype, with mesenchymal-like cells displaying greater susceptibility than epithelial-like counterparts. Collectively, these findings identify ferritin as a central regulator of iron tolerance in MB and establish iron toxicity, not via iron deprivation, as a therapeutically exploitable vulnerability. More broadly, this work provides a mechanistic framework for targeting iron metabolism through modulation of ferritin-dependent iron buffering and iron redox homeostasis in cancers.