At the core of this breakthrough are multifunctional copper-based nano-PROTACs, referred to as CHNDs. These nanoscale agents seamlessly integrate targeted protein degradation technology with copper-mediated cytotoxicity. The molecular target of this system is hexokinase 2 (HK-2), a pivotal enzyme responsible for initiating glycolysis by phosphorylating glucose. HK-2 is heavily exploited by rapidly proliferating cancer cells to sustain their elevated metabolic demands. Unlike conventional inhibitors, CHNDs harness the power of proteolysis targeting chimeras (PROTACs) to degrade HK-2, thereby effectively precluding the enzyme’s compensatory activation and quelling glycolytic flux with superior potency.

The initial step in the researchers’ design involved engineering PEI-based HK-2 degraders, dubbed PHDs. These molecular constructs are composed of a 3-bromopyruvate moiety—a covalent warhead that specifically binds to HK-2—linked to a thalidomide derivative, which acts as a recruiting ligand for the cereblon E3 ubiquitin ligase. This architectural assembly orchestrates proximity-induced ubiquitination, guiding HK-2 to the proteasome for rapid degradation. Experimental application in murine 4T1 breast cancer and CT26 colon cancer cell models confirmed that PHD treatment resulted in a significant diminution of HK-2 protein levels, reducing expression by over 40%, which translated into marked inhibition of glycolytic activity.

Building upon this foundation, the research team developed the CHND platform by adorning copper-based metal–organic framework (MOF) nanoparticles with polyethylene glycol (PEG)-linked PHDs. This design ensures nanoparticle stability within the bloodstream while enabling the preferential release of bioactive components in the acidic and glutathione-rich microenvironment characteristic of tumors. Upon accumulation in cancerous tissue, the CHNDs disassemble, releasing copper ions alongside PEG-PHD conjugates. The liberated PEG-PHDs perpetuate the degradation of HK-2, curtailing glycolysis, while copper ions initiate mitochondrial perturbations. This triggers cuproptosis, a unique form of cell death distinguished by DLAT protein aggregation and disturbance of iron–sulfur cluster proteins critical for mitochondrial function.

Cellular assays vividly demonstrated that CHND treatment surpassed the efficacy of either copper nanoparticles or HK-2 degraders alone. The combinatorial therapy led to pronounced suppression of glycolytic flux and reduced lactate production, key indicators of disrupted energy metabolism. Concurrently, intracellular ATP levels plummeted, reactive oxygen species surged, and mitochondrial membrane potential dissipated, hallmarks of mitochondrial distress. Moreover, DLAT aggregation was amplified, further corroborating the activation of cuproptotic pathways. These multifaceted perturbations showcase the potency of CHNDs in orchestrating dual metabolic inhibition.

Delving deeper into the mechanistic underpinnings, transcriptomic profiling of CHND-treated cancer cells unveiled widespread dysregulation across multiple biological processes. Genes implicated in proteasome activity, ubiquitin-mediated proteolysis, and endoplasmic reticulum protein processing were notably disrupted, indicating substantial disturbance in protein homeostasis. Additionally, pathways governing oxidative stress responses, mitochondrial respiratory chain assembly, and oxidative phosphorylation were profoundly affected, underscoring the comprehensive assault on cellular redox balance and bioenergetics. These transcriptomic insights reinforce the concept that CHNDs execute their antitumor effects by coordinating a simultaneous collapse of metabolic, proteostatic, and redox networks essential for cancer cell survival.

Translating these findings in vivo, the study employed several murine tumor models to evaluate therapeutic efficacy. In orthotopic 4T1 breast cancer models, CHND administration led to a striking 55.3% reduction in tumor volume. Even more compelling, in CT26 colon carcinoma models, tumor inhibition reached a substantial 76.6%, accompanied by a significant extension of median survival from 21 to 29 days. Remarkably, a subset of animals treated with CHNDs survived beyond 100 days, highlighting the potential for durable therapeutic responses. Histopathological analyses of excised tumors corroborated these outcomes by demonstrating pronounced HK-2 depletion, enhanced DLAT aggregation, and elevated indicators of tumor cell apoptosis.

The impact of CHNDs extended beyond primary tumors, revealing promising antimetastatic activity. In a spontaneous lung metastasis model derived from 4T1 breast cancer cells, animals receiving CHND treatment exhibited markedly reduced bioluminescent signals in lung tissue, alongside fewer metastatic nodules upon gross examination. These findings suggest that impairing glycolytic compensation and mitochondrial function collectively stymie not only tumor growth but also metastatic dissemination—an important advantage given the lethality of metastatic disease in clinical oncology.

Importantly, the study situates itself at the intersection of metal-ion cytotoxicity and targeted protein degradation—two therapeutic strategies that have historically advanced along separate tracks. CHNDs embody a novel paradigm by merging these modalities within a single nanoplatform, effectively converting copper from a mere cytotoxic agent to an integral component of a precision metabolic intervention. This synergistic approach capitalizes on the inherent vulnerabilities of cancer metabolism, specifically the reliance on HK-2-driven glycolysis and mitochondrial respiration, pushing cancer cells beyond the limits of metabolic plasticity.

Despite these compelling preclinical results, the path to clinical application will require further investigations. Key challenges include evaluating long-term implications of metal ion accumulation, potential immunogenicity of the metal-organic nanoparticles, pharmacokinetic profiles, and intertumoral heterogeneity that may influence therapeutic response. Additionally, rigorous safety assessments in larger animal models will be critical to address off-target effects and ensure tolerability. Nonetheless, the study’s conceptual advancement sets the stage for future translational efforts aiming to refine and harness integrated metabolic cancer therapies.

As a methodical example of engineering multifunctional nanotherapeutics capable of targeted protein degradation coupled with metal ion-induced cell death, this work heralds a new horizon in precision oncology. The elegant coupling of HK-2 degradation and cuproptosis induction illustrates the power of simultaneous multi-route blockade of cancer metabolism. Such integrative strategies offer hope in overcoming the formidable challenge posed by metabolic adaptability—a hallmark of malignant neoplasms—and may ultimately catalyze the development of next-generation treatments that improve patient outcomes and survival.

In summary, the development of CHNDs exemplifies a landmark advancement in multifunctional nanomedicine, where metabolic inflexibility is exploited for therapeutic gain. By joining copper-triggered mitochondrial stress with the targeted degradation of a glycolytic gatekeeper, this nanoplatform disrupts the core energetic and proteostatic infrastructure required for tumor sustenance. This synergistic assault on malignancy validates the strategy of coupling metal-induced cuproptosis with degradation of glycolytic enzymes as a powerful approach to cancer treatment, offering a promising avenue for future research and clinical translation.

Subject of Research: Not applicable

Article Title: Multifunctional Engineered Metal–Organic Frameworks as Targeted Protein Degraders for Augmenting Cancer Therapy via Hexokinase 2 Degradation and Provoking Cuproptosis

News Publication Date: 31-Mar-2026

Web References: 10.34133/research.1217

Keywords: cuproptosis, cancer metabolism, hexokinase 2, targeted protein degradation, metal–organic frameworks, nanomedicine, glycolysis inhibition, mitochondrial stress, 3-bromopyruvate, copper ions, reactive oxygen species, proteostasis

Cancer cells are notorious for their altered metabolism, often characterized by an elevated glycolytic rate even in the presence of oxygen—a phenomenon termed the Warburg effect. This adaptation not only fuels rapid proliferation but also contributes to tumor progression and resistance to therapy. Targeting glycolysis, therefore, represents a compelling avenue for anticancer intervention. However, identifying agents that can selectively and effectively modulate glycolytic metabolism without harming normal cells has remained challenging.

The research team utilized a comprehensive suite of advanced proteomic and metabolomic technologies to decipher the molecular impact of 6-methoxyflavone on HeLa cells. Tandem mass tag (TMT) proteomics enabled them to quantitatively profile global protein expression changes, revealing significant downregulation in proteins directly involved in the glycolysis pathway. Complementing these findings, parallel reaction monitoring (PRM) proteomics validated the reduced abundance of several key glycolytic enzymes, underscoring a consistent suppression of this vital energy-generating cascade.

Beyond proteins, the metabolome landscape was interrogated using both untargeted and targeted metabolomic analyses. These approaches uncovered decreased levels of critical glycolytic intermediates and metabolites, confirming that 6-methoxyflavone not only alters protein expression but also visibly disrupts cellular metabolic flux through glycolysis. Such metabolic reprogramming is crucial as it deprives cancer cells of the energy and biosynthetic precursors needed for their uncontrolled growth.

Importantly, the study delved deeper into molecular mechanisms by analyzing alternative splicing events, novel transcript formation, and domain alterations in glycolysis-related genes. These structural gene and protein modifications hint at a complex regulatory network influenced by 6-methoxyflavone, affecting not only protein abundance but also their functional integrity and interactions within the cytoplasm.

To further clarify molecular interactions, researchers employed in silico molecular docking coupled with non-covalent interaction analyses. These techniques highlighted how 6-methoxyflavone exhibits high binding affinity to nine critical glycolysis-related proteins, binding specifically through non-covalent interactions. This affinity suggests a direct inhibitory effect of the compound on enzyme activity, which was experimentally substantiated by the notable suppression of pyruvate kinase activity—a pivotal step in glycolysis.

At the cellular level, glycolytic function was quantitatively assessed via glycolysis stress tests, which revealed that treatment with 6-methoxyflavone decisively reduced the basal glycolytic rate, maximum glycolytic capacity, and glycolytic reserve of HeLa cells. These findings collectively indicate that the compound impairs the energetic flexibility of cancer cells, potentially sensitizing them to metabolic stress and therapeutic assault.

Beyond in vitro assays, the study explored clinical correlations by integrating patient data. Analyses demonstrated that glycolysis-related gene expression levels influenced by 6-methoxyflavone correlated with key clinical features, survival outcomes, and immunological parameters in cervical cancer patients. This bridge between molecular findings and clinical relevance suggests potential translational applications for this compound in prognostic assessment and therapy design.

Particularly intriguing were observations connecting 6-methoxyflavone activity with tumor immune microenvironment modulation. Alterations in immune cell infiltration and immune checkpoint marker expression upon compound treatment suggest that, beyond metabolic disruption, 6-methoxyflavone may also prime tumors for enhanced immunotherapeutic responsiveness.

The multifaceted nature of 6-methoxyflavone’s actions underscores its promise as an anticancer agent. By targeting the fundamental bioenergetic machinery of cancer cells and potentially modulating immune milieu, it could represent a dual mechanism to suppress tumor growth and improve patient outcomes.

This study not only provides novel mechanistic insights into how flavonoid derivatives inhibit glycolysis but also opens avenues for combination therapy strategies. For instance, pairing metabolic inhibitors like 6-methoxyflavone with immune checkpoint blockade might synergistically enhance therapeutic efficacy against cervical cancer.

Moreover, the rigorous methodological framework—combining state-of-the-art proteomics, metabolomics, computational modeling, and clinical data analysis—sets a benchmark for future cancer metabolism research. Such integrative approaches enable comprehensive evaluation of candidate molecules, bridging basic science discoveries with precision medicine initiatives.

While the current research focuses specifically on HeLa cells and cervical cancer, the implications extend broadly. Glycolytic dysregulation is a hallmark of diverse cancers, raising the possibility that 6-methoxyflavone or structurally related compounds could exert similar metabolic inhibitory effects across multiple tumor types.

Further investigations will be essential to determine the in vivo efficacy, safety profile, and pharmacokinetics of 6-methoxyflavone. Additionally, probing its impact within the complex tumor ecosystem, including stromal and immune cell interactions, will be crucial to fully harness its clinical potential.

In conclusion, the identification of 6-methoxyflavone as a glycolysis inhibitor marks a significant step forward in cancer metabolism targeting. By impairing energy production at multiple molecular levels, it effectively cripples the metabolic flexibility cancer cells rely on, paving the way for novel therapeutic strategies in cervical cancer management.

—

Subject of Research: Regulation of glycolytic energy metabolism by 6-methoxyflavone in cervical cancer (HeLa) cells.

Article Title: 6-Methoxyflavone inhibits glycolytic energy metabolism in HeLa cells.

Article References:

Zhang, C., Chen, L. 6-Methoxyflavone inhibits glycolytic energy metabolism in HeLa cells.
BMC Cancer 25, 719 (2025). https://doi.org/10.1186/s12885-025-14133-9

Image Credits: Scienmag.com

DOI: https://doi.org/10.1186/s12885-025-14133-9