What happens if cancer cells lose both their mitochondrial energy supply and their glycolytic backup system? This question is central to a new study published in Research by researchers from Northwestern Polytechnical University and collaborating institutions. The work addresses a key limitation of cuproptosis-based cancer therapy: copper-dependent mitochondrial stress can kill cancer cells, but many tumors are metabolically flexible and rely heavily on aerobic glycolysis to survive mitochondrial damage. The study proposes a way to block both routes at once.
The researchers designed multifunctional copper-based nano-PROTACs, named CHNDs, that combine targeted protein degradation with copper-mediated cell death. The protein target is hexokinase 2, or HK-2, a key enzyme that catalyzes the first committed step of glycolysis and supports the high metabolic demand of rapidly growing tumors. By degrading HK-2 rather than simply inhibiting it, the platform aims to reduce glycolytic compensation more effectively.
The team first constructed PEI-based HK-2 degraders, termed PHDs. These degraders link a 3-bromopyruvate warhead that engages HK-2 with a thalidomide derivative that recruits the cereblon E3 ligase. This design brings HK-2 close to the ubiquitin–proteasome system, enabling targeted degradation. In 4T1 breast cancer cells and CT26 colon cancer cells, PHDs reduced HK-2 expression to about 43.7% and 42.1%, respectively, impairing glycolytic activity.
To integrate this degradation strategy with cuproptosis, the researchers built CHNDs from copper-based metal–organic framework nanoparticles decorated with PEGylated PHDs. The particles remain relatively stable under physiological conditions but disassemble more readily in tumor-like acidic and glutathione-rich environments. This allows the system to release copper ions and PEG-PHDs in a controlled manner. PEG-PHDs suppress glycolysis through HK-2 degradation, while copper ions trigger mitochondrial stress, DLAT aggregation, iron–sulfur protein disruption, and cuproptotic cell death.
In cell experiments, CHNDs showed stronger anticancer activity than either the HK-2 degrader or the copper nanoplatform alone. The treatment reduced glycolytic flux, lactate production, and ATP levels, while increasing reactive oxygen species, depolarizing mitochondria, and promoting DLAT aggregation. Transcriptomic analysis further showed broad disruption of proteasome activity, ubiquitin-mediated proteolysis, endoplasmic reticulum protein processing, oxidative stress responses, mitochondrial respiratory chain assembly, and oxidative phosphorylation. Together, these results indicate that CHNDs act through coordinated disruption of protein homeostasis, redox balance, and cancer energy metabolism.
The strategy also showed antitumor effects in mouse models. In an orthotopic 4T1 breast cancer model, CHNDs achieved a tumor inhibition rate of 55.3%. In a CT26 colon tumor model, the inhibition rate reached 76.6%, and median survival increased from 21 to 29 days, with a subset of animals surviving to day 100. Tumor tissue analyses confirmed HK-2 down-regulation, enhanced DLAT aggregation, and increased tumor cell death. In a spontaneous lung metastasis model using 4T1 breast tumors, CHNDs also reduced lung bioluminescence signals and metastatic nodules, suggesting potential antimetastatic activity.
The study offers a mechanistic framework for strengthening cuproptosis therapy by shutting down glycolytic compensation. Rather than treating copper toxicity and tumor metabolism as separate targets, CHNDs bring them together in one nanoplatform. Still, the work remains preclinical. Long-term metal ion accumulation, immunological consequences, pharmacokinetics, tumor heterogeneity, and safety in larger animal models will need careful evaluation before this strategy can move toward clinical translation. Even at this stage, the study provides a valuable example of how targeted protein degradation and metal-induced cell death can be integrated for precision metabolic cancer therapy.
The complete study is accessible via DOI: