What happens when cancer cells lose both their mitochondrial energy supply and their glycolytic backup system? This question is at the heart of a new study published in 2006 the study By researchers at Northwestern Technological University and partner institutions. This study addresses an important limitation of cuprupholosis-based cancer therapy: although copper-dependent mitochondrial stress can kill cancer cells, many tumors are metabolically malleable and rely heavily on aerobic glycolysis to survive mitochondrial damage. This study proposes a method to block both routes at once.
The researchers designed a multifunctional copper-based nanoPROTAC, called CHND, that combines targeted protein degradation and copper-mediated cell death. The protein target is hexokinase 2 (HK-2). It is a key enzyme that catalyzes the first participating step of glycolysis and supports the high metabolic demands of rapidly growing tumors. This platform aims to more effectively reduce glycolytic compensation by degrading HK-2 rather than simply inhibiting it.
The team first built a PEI-based HK-2 decomposer called PHD. These degradants bind a 3-bromopyruvate warhead that binds HK-2 and a thalidomide derivative that recruits cereblon E3 ligase. This design brings HK-2 closer to the ubiquitin-proteasome system, allowing for targeted degradation. In 4T1 breast cancer cells and CT26 colon cancer cells, PHD reduced HK-2 expression to approximately 43.7% and 42.1%, respectively, and impaired glycolytic activity.
To integrate this degradation strategy with cuproptosis, researchers constructed CHNDs from copper-based metal-organic framework nanoparticles modified with PEGylated PHD. Although the particles are relatively stable under physiological conditions, they degrade more easily in acidic, glutathione-rich environments such as tumors. This allows the system to release copper ions and PEG-PHD in a controlled manner. PEG-PHD inhibits glycolysis through HK-2 degradation, while copper ions cause mitochondrial stress, DLAT aggregation, iron-sulfur protein destruction, and cuproptotic cell death.
In cell experiments, CHND showed stronger anticancer activity than the HK-2 degrader or the copper nanoplatform alone. This treatment decreased glycolytic flux, lactate production, and ATP levels, while increasing reactive oxygen species, depolarizing mitochondria, and promoting DLAT aggregation. Transcriptome analysis further showed widespread disruption of proteasome activity, ubiquitin-mediated protein degradation, endoplasmic reticulum protein processing, oxidative stress response, mitochondrial respiratory chain assembly, and oxidative phosphorylation. Collectively, these results indicate that CHND acts through coordinated disruption of protein homeostasis, redox balance, and cancer energy metabolism.
This strategy also showed antitumor effects in mouse models. In an orthotopic 4T1 breast cancer model, CHND achieved a tumor suppression rate of 55.3%. In the CT26 colon tumor model, the inhibition rate reached 76.6% and the median survival increased from 21 to 29 days, with some animals surviving up to 100 days. Tumor tissue analysis confirmed downregulation of HK-2, enhanced DLAT aggregation, and increased tumor cell death. In a spontaneous lung metastasis model using 4T1 breast tumors, CHND also reduced lung bioluminescent signals and metastatic nodules, suggesting potential anti-metastatic activity.
This study provides a mechanistic framework to enhance leukocytosis treatment by halting glycolytic compensation. Rather than treating copper toxicity and tumor metabolism as separate targets, CHND brings them together in one nanoplatform. Still, this research is still in the preclinical stage. Before translating this strategy into clinical application, long-term metal ion accumulation, immunological effects, pharmacokinetics, tumor heterogeneity, and safety in larger animal models must be carefully evaluated. Even at this stage, this study provides a valuable example of how targeted protein degradation and metal-induced cell death can be integrated into precision metabolic cancer therapy.
sauce:
Science and Technology Review Publishing
Reference magazines:
Lee, S. Others. (2026). Multifunctionally engineered metal-organic frameworks as targeted proteolytic agents to enhance cancer therapy through hexokinase 2 degradation and induction of cuproptosis. the study. DOI: 10.34133/research.1217. https://spj.science.org/doi/10.34133/research.1217
