Blocking MTCH2 Triggers Ferroptosis and Boosts Sorafenib Against Colon Cancer Spread
Loss of mitochondrial protein MTCH2 unleashes iron-driven cell death in colorectal cancer and dramatically enhances sorafenib's power against liver metastases.
Summary
Researchers at Peking University Cancer Hospital identified MTCH2, a mitochondrial outer membrane protein, as a key suppressor of ferroptosis in colorectal cancer (CRC). High MTCH2 expression in CRC tissue correlated with worse survival, deeper invasion, and lymph node spread. When MTCH2 was knocked out—in cell lines, mouse models, and liver metastasis models—iron accumulated inside tumor cells, lipid peroxidation surged, and ferroptotic cell death increased. Mechanistically, MTCH2 loss destabilized the transcription repressor E2F4 via proteasomal degradation, relieving its suppression of the iron-import receptor TFRC and flooding cells with ferrous iron. Combining MTCH2 depletion with sorafenib synergistically amplified ferroptosis and nearly eliminated liver metastatic foci in mice, pointing to a clinically actionable MTCH2/E2F4/TFRC therapeutic axis.
Detailed Summary
Colorectal cancer (CRC) kills roughly half of affected patients through distant metastasis, most commonly to the liver, yet the molecular drivers of this lethal spread remain incompletely understood. This 2025 study in Advanced Science from Peking University Cancer Hospital identifies the mitochondrial carrier homolog 2 (MTCH2, also SLC25A50) as a previously unrecognized gatekeeper of ferroptosis—an iron-dependent, lipid-peroxide-driven form of programmed cell death—in CRC progression and metastasis.
Using immunohistochemistry on 172 CRC patient tissue arrays, qRT-PCR, Western blotting, and public databases (TCGA, GEO GSE20842/GSE103512), the authors showed that MTCH2 is significantly overexpressed in both colon and rectal adenocarcinoma compared with normal mucosa. High MTCH2 correlated independently with deeper tumor invasion, lymph node metastasis, and advanced TNM stage, and Kaplan–Meier analysis confirmed that high MTCH2 predicted significantly shorter overall survival in both COAD and READ cohorts.
Functionally, MTCH2 knockout (MTCH2-KO) in RKO and HCT116 CRC cell lines reduced proliferation, migration, and invasion while increasing intracellular ferrous iron (Fe²⁺), lipid ROS, and malondialdehyde—hallmarks of ferroptosis—effects reversed by the ferroptosis inhibitor ferrostatin-1. In vivo, intestinal epithelium-specific MTCH2 conditional knockout mice (MTCH2^cKO) subjected to the AOM/DSS colorectal tumorigenesis protocol developed significantly fewer and smaller tumors than wild-type controls. Orthotopic and splenic-injection liver metastasis mouse models confirmed that MTCH2 depletion suppressed hepatic colonization and tumor burden.
Mechanistically, the study pinpoints a novel MTCH2/E2F4/TFRC signaling axis. MTCH2 loss accelerated proteasome-dependent ubiquitination and degradation of E2F4, a transcriptional repressor that normally binds the TFRC promoter and suppresses its expression. With E2F4 destabilized, TFRC (transferrin receptor 1) was transcriptionally de-repressed, boosting iron import, Fe²⁺ accumulation, and ferroptotic sensitivity. ChIP and luciferase reporter assays confirmed direct E2F4 occupancy at the TFRC promoter, and rescue experiments with E2F4 overexpression or TFRC knockdown reversed the ferroptotic phenotype caused by MTCH2 loss.
Translationally, the combination of MTCH2 depletion with sorafenib—a multikinase inhibitor already used in hepatocellular carcinoma and known to inhibit the ferroptosis-suppressing system Xc⁻/GPX4 axis—produced synergistic ferroptosis induction in vitro and near-complete eradication of liver metastatic foci in mouse models, outperforming either intervention alone. These findings position MTCH2 as both a prognostic biomarker and a druggable target whose inhibition could sensitize CRC liver metastases to sorafenib, offering a rationale for combination clinical trials.
Key Findings
- MTCH2 is overexpressed in CRC versus normal mucosa and high expression independently predicts poor overall survival.
- MTCH2 knockout increases intracellular Fe²⁺, lipid ROS, and ferroptosis in CRC cells in vitro and in vivo.
- MTCH2 loss destabilizes transcription repressor E2F4 via proteasomal ubiquitination, de-repressing TFRC and amplifying iron uptake.
- MTCH2-deficient mice show markedly reduced AOM/DSS-induced colorectal tumor burden and suppressed liver metastasis.
- MTCH2 depletion plus sorafenib synergistically triggers ferroptosis and nearly eliminates liver metastatic foci in mouse models.
Methodology
The study combined IHC on 172 CRC patient tissue arrays, TCGA/GEO database analyses, CRISPR/shRNA-based MTCH2 knockout in CRC cell lines, intestinal epithelium-specific conditional knockout mice with AOM/DSS tumorigenesis, orthotopic and splenic-injection liver metastasis mouse models, and mechanistic assays including ChIP, luciferase reporter, co-immunoprecipitation, and ubiquitination assays to delineate the MTCH2/E2F4/TFRC axis.
Study Limitations
All in vivo combination therapy data are from mouse models; no human pharmacological MTCH2 inhibitor currently exists, making direct clinical translation contingent on drug development. The study does not fully characterize how MTCH2 stabilizes E2F4 at the protein level, leaving upstream regulatory details unresolved. Patient cohort analyses are retrospective and single-institution, requiring validation in larger, prospective multicenter cohorts.
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