Tumor metabolism destruction via metformin-based glycolysis inhibition and glucose oxidase-mediated glucose deprivation for enhanced cancer therapy

A pH/GSH Dual-Responsive Triple Synergistic Bimetallic Nanocatalyst for Enhanced Tumor Chemodynamic Therapy

Chemodynamic therapy (CDT) has garnered significant attention in the field of tumor therapy due to its ability to convert overexpressed hydrogen peroxide (H2O2) in tumors into highly toxic hydroxyl radicals (•OH) through metal ion-mediated catalysis. However, the effectiveness of CDT is hindered by low catalyst efficiency, insufficient intra-tumor H2O2 level, and excessive glutathione (GSH). In this study, a pH/GSH dual responsive bimetallic nanocatalytic system (CuFeMOF@GOx@Mem) is developed by modifying red blood cell membranes onto glucose oxidase (GOx)-loaded Fe-Cu bimetallic MOFs, enhancing the efficacy of CDT through a triple-enhanced way by H2O2 self-supply, catalysts self-cycling, and GSH self-elimination. Upon accumulation in tumor tissues facilitated by the red blood cell membrane, the GOx initiates a reaction with glucose to generate H2O2 and gluconic acid in situ. Subsequently, the reduced pH triggers the release of Fe3+ and Cu2+ from CuFeMOF@GOx@Mem, which is immediately turned into Fe2+ and Cu+ by GSH, activating the Fe2+-mediated Fenton reaction. More importantly, Cu+ can also act as an accelerator of Fe3+/Fe2+ conversion, meanwhile, the generated Cu2+ can be further reduced to Cu+ by GSH. Consequently, sustained accumulation of H2O2 and Fe2+ as well as sustained elimination of GSH are achieved simultaneously, providing a unique approach for improving the anti-tumor ability of CDT.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

Electroporation enhances cell death in 3D scaffold-based MDA-MB-231 cells treated with metformin

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer lacks estrogen, progesterone, and HER2 receptors and hence, is therapeutically challenging. Towards this, we studied an alternate therapy by repurposing metformin (FDA-approved type-2 diabetic drug with anticancer properties) in a 3D-scaffold culture, with electrical pulses. 3D cell culture was used to simulate the tumor microenvironment more closely and MDA-MB-231, human TNBC cells, treated with both 5 mM metformin (Met) and 8 electrical pulses at 2500 V/cm, 10 µs (EP1) and 800 V/cm, 100 µs (EP2) at 1 Hz were studied in 3D and 2D. They were characterized using cell viability, reactive oxygen species (ROS), glucose uptake, and lactate production assays at 24 h. Cell viability, as low as 20 % was obtained with EP1 + 5 mM Met. They exhibited 1.65-fold lower cell viability than 2D with EP1 + 5 mM Met. ROS levels indicated a 2-fold increase in oxidative stress for EP1 + 5 mM Met, while the glucose uptake was limited to only 9 %. No significant change in the lactate production indicated glycolytic arrest and a non-conducive environment for MDA-MB-231 growth. Our results indicate that 3D cell culture, with a more realistic tumor environment that enhances cell death using metformin and electrical pulses could be a promising approach for TNBC therapeutic intervention studies.

Validation of quercetin in the treatment of colon cancer with diabetes via network pharmacology, molecular dynamics simulations, and in vitro experiments

This study built a prognostic model for CRC-diabetes and analyzed whether quercetin could be used for CRC-diabetes treatment through a network of pharmacology, molecular dynamics simulation, bioinformatics, and in vitro experiments. First, multivariate Cox proportional hazards regression was used to construct the prognosis modelof CRC-diabetes. Then, the intersection of quercetin target genes with CRC-diabetes genes was used to find the potential target for quercetin in the treatment of CRC-diabetes. Molecular docking and molecular dynamics simulations were used to screen the potential targets for quercetin in the treatment of CRC-diabetes. Finally, we verified the target and pathway of quercetin in the treatment of CRC-diabetes through in vitro experiments. Through molecular docking, seven proteins (HMOX1, ACE, MYC, MMP9, PLAU, MMP3, and MMP1) were selected as potential targets of quercetin. We conducted molecular dynamics simulations of quercetin and the above proteins, respectively, and found that the binding structure of quercetin with MMP9 and PLAU was relatively stable. Finally, according to the results of Western blot results, it was confirmed that quercetin could interact with MMP9. The experimental results show that quercetin may affect the JNK pathway, glycolysis, and epithelial-mesenchymal transition (EMT) to treat CRC-diabetes. Based on the TCGA, TTD, DrugBank, and other databases, a prediction model that can effectively predict the prognosis of colon cancer patients with diabetes was constructed. According to experiment results, quercetin can regulate the expression of MMP9. By acting on the JNK pathway, glycolysis, and EMT, it can treat colon cancer patients with diabetes.

Iron-Based Metal-Organic Frameworks as Multiple Cascade Synergistic Therapeutic Effect Nano-Drug Delivery Systems for Effective Tumor Elimination

Efforts have been made to improve the therapeutic efficiency of tumor treatments, and metal-organic frameworks (MOFs) have shown excellent potential in tumor therapy. Monotherapy for the treatment of tumors has limited effects due to the limitation of response conditions and inevitable multidrug resistance, which seriously affect the clinical therapeutic effect. In this study, we chose to construct a multiple cascade synergistic tumor drug delivery system MIL-101(Fe)-DOX-TCPP-MnO2@PDA-Ag (MDTM@P-Ag) using MOFs as drug carriers. Under near-infrared (NIR) laser irradiation, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and Ag NPs loaded on MDTM@P-Ag can be activated to generate cytotoxic reactive oxygen species (ROS) and achieve photothermal conversion, thus effectively inducing the apoptosis of tumor cells and achieving a combined photodynamic/photothermal therapy. Once released at the tumor site, manganese dioxide (MnO2) can catalyze the decomposition of hydrogen peroxide (H2O2) in the acidic microenvironment of the tumor to generate oxygen (O2) and alleviate the hypoxic environment of the tumor. Fe3+/Mn2+ will mediate a Fenton/Fenton-like reaction to generate cytotoxic hydroxyl radicals (·OH), while depleting the high concentration of glutathione (GSH) in the tumor, thus enhancing the chemodynamic therapeutic effect. The successful preparation of the tumor drug delivery system and its good synergistic chemodynamic/photodynamic/photothermal therapeutic effect in tumor treatment can be demonstrated by the experimental results of material characterization, performance testing and in vitro experiments.

Boosting Energy Deprivation by Synchronous Interventions of Glycolysis and Oxidative Phosphorylation for Bioenergetic Therapy Synergetic with Chemodynamic/Photothermal Therapy

Bioenergetic therapy is emerging as a promising therapeutic approach. However, its therapeutic effectiveness is restricted by metabolic plasticity, as tumor cells switch metabolic phenotypes between glycolysis and oxidative phosphorylation (OXPHOS) to compensate for energy. Herein, Metformin (MET) and BAY-876 (BAY) co-loaded CuFe2O4 (CF) nanoplatform (CFMB) is developed to boost energy deprivation by synchronous interventions of glycolysis and OXPHOS for bioenergetic therapy synergetic with chemodynamic/photothermal therapy (CDT/PTT). The MET can simultaneously restrain glycolysis and OXPHOS by inhibiting hexokinase 2 (HK2) activity and damaging mitochondrial function to deprive energy, respectively. Besides, BAY blocks glucose uptake by inhibiting glucose transporter 1 (GLUT1) expression, further potentiating the glycolysis repression and thus achieving much more depletion of tumorigenic energy sources. Interestingly, the upregulated antioxidant glutathione (GSH) in cancer cells triggers CFMB degradation to release Cu+/Fe2+ catalyzing tumor-overexpressed H2O2 to hydroxyl radical (∙OH), both impairing OXPHOS and achieving GSH-depletion amplified CDT. Furthermore, upon near-infrared (NIR) light irradiation, CFMB has a photothermal conversion capacity to kill cancer cells for PTT and improve ∙OH production for enhanced CDT. In vivo experiments have manifested that CFMB remarkably suppressed tumor growth in mice without systemic toxicity. This study provides a new therapeutic modality paradigm to boost bioenergetic-related therapies.

Systems-wide analysis of A. fumigatus using kinetic modeling of metabolic pathways to identify putative drug targets

Aspergillosis is a major causative factor for morbidity in those with impaired immune systems, often caused by Aspergillus fumigatus. The diagnosis and treatment are difficult due to the diversity of individuals and risk factors and still pose a challenge for medical professionals. To understand the pathogenicity of any organism, it is critical to identify the significant metabolic pathways that are involved. Our work focused on developing kinetic models of critical pathways crucial for the survival of A. fumigatus using COPASI. While focusing on the folate biosynthesis, ergosterol biosynthesis and glycolytic pathway; sensitivity, time-course and steady-state analysis were performed to find the proteins/enzymes that are essential in the pathway and can be considered as potential drug targets. For further analysis of the interaction of drug targets identified, a protein-protein interaction (PPI) network was built, and hub nodes were identified using the Cytohubba package from Cytoscape. Based on the findings, dihydropteroate-synthase, dihydrofolate-reductase, 4-amino-4-deoxychorismate synthase, HMG-CoA-reductase, PG-isomerase and hexokinase could act as potential drug targets. Further, molecular docking and MM-GBSA analysis were performed with ligands chosen from DrugBank, and PubChem, and validated by experimental evidence and existing literature based on results from kinetic modeling and PPI network analysis. Based on docking scores and MM-GBSA results, molecular simulations were carried out for 1AJ2-dapsone, 1DIS-sulfamethazine, 1T02-lovastatin and 70YL-3-bromopyruvic acid complexes, which validated our findings. Our study provides a deeper insight into the mechanisms of A. fumigatus's metabolism to reveal dapsone, sulfamethazine, lovastatin and 3-bromopyruvic acid as potential drugs for the treatment of Aspergillosis.

Red blood cell membrane-coated functionalized Cu-doped metal organic framework nanoformulations as a biomimetic platform for improved chemo-/chemodynamic/photothermal synergistic therapy

Nanoformulations for combining chemotherapy, chemodynamic therapy, and photothermal therapy have enormous potential in tumor treatment. Coating nanoformulations with cell membranes endows them with homologous cellular mimicry, enabling nanoformulations to acquire new functions and properties, including homologous targeting and long circulation in vivo, and can enhance internalization by homologous cancer cells. Herein, we fused multifunctional biomimetic nanoformulations based on Cu-doped zeolitic imidazolate framework-8 (ZIF-8). Hydroxycamptothecin (HCPT), a clinical anti-tumor drug, was encapsulated into ZIF-8, which was subsequently coated with polydopamine (PDA) and red blood cell membrane. The as-fabricated biomimetic nanoformulations showed an enhanced cell uptake in vitro and the potential to prolong blood circulation in vivo, producing effective synergistic chemotherapy, chemodynamic therapy, and photothermal therapy under the 808 nm laser irradiation. Together, the biomimetic nanoformulations showed a prolonged blood circulation and evasion of immune recognition in vivo to provide a bio-inspired strategy which may have the potential for the multi-synergistic therapy of breast cancer.

Enhancing metformin-induced tumor metabolism destruction by glucose oxidase for triple-combination therapy

Despite decades of laboratory and clinical trials, breast cancer remains the main cause of cancer-related disease burden in women. Considering the metabolism destruction effect of metformin (Met) and cancer cell starvation induced by glucose oxidase (GOx), after their efficient delivery to tumor sites, GOx and Met may consume a large amount of glucose and produce sufficient hydrogen peroxide in situ. Herein, a pH-responsive epigallocatechin gallate (EGCG)-conjugated low-molecular-weight chitosan (LC-EGCG, LE) nanoparticle (Met-GOx/Fe@LE NPs) was constructed. The coordination between iron ions (Fe3+) and EGCG in this nanoplatform can enhance the efficacy of chemodynamic therapy via the Fenton reaction. Met-GOx/Fe@LE NPs allow GOx to retain its enzymatic activity while simultaneously improving its stability. Moreover, this pH-responsive nanoplatform presents controllable drug release behavior. An in vivo biodistribution study showed that the intracranial accumulation of GOx delivered by this nanoplatform was 3.6-fold higher than that of the free drug. The in vivo anticancer results indicated that this metabolism destruction/starvation/chemodynamic triple-combination therapy could induce increased apoptosis/death of tumor cells and reduce their proliferation. This triple-combination therapy approach is promising for efficient and targeted cancer treatment.

An Intelligent and Soluble Microneedle Composed of Bi/BiVO4 Schottky Heterojunction for Tumor Ct Imaging and Starvation/Gas Therapy-Promoted Synergistic Cancer Treatment

Phototherapy and sonodynamic therapy (SDT) are widely used for the synergistic treatment of tumors and have received considerable attention. However, an inappropriate tumor microenvironment, including pH, H2O2, oxygen, and glutathione levels, can reduce the therapeutic effects of synergistic phototherapy and SDT. Here, a novel Bi-based soluble microneedle (MN) is designed for the CT imaging of breast tumors and starvation therapy/gas therapy-enhanced phototherapy/SDT. The optimized Bi/BiVO4 Schottky heterojunction serves as the tip of the MN, which not only has excellent photothermal conversion ability and CT contrast properties, but its heterojunction can also avoid the rapid combination of electrons and hole pairs, thereby enhancing the photodynamic/sonodynamic effects. A degradable MN with excellent mechanical properties is fabricated by optimizing the ratios of poly(vinyl alcohol), poly(vinyl pyrrolidone), and sodium hyaluronate. Glucose oxidase (GOx) and diallyl trisulfide are loaded into the MN to achieve tumor starvation and gas therapy, respectively; And the controlled release of GOx and H2S can be achieved under ultrasound or near-infrared laser irradiation. The in vitro and in vivo results demonstrate that this multifunctional MN can achieve high therapeutic efficacy through starvation therapy/gas therapy-enhanced phototherapy/SDT. The designed multifunctional MN provides a prospective approach for synergistic phototherapy and SDT.

Tunable Zeolitic Imidazolate Framework-8 Nanoparticles for Biomedical Applications

Zeolite imidazole framework-8 (ZIF-8) is the most prestigious one among zeolitic imidazolate framework (ZIF) with tunable dimensions and unique morphological features. Utilizing its synthetic adjustability and structural regularity, ZIF-8 exhibits enhanced flexibility, allowing for a wide range of functionalities, such as loading of nanoparticle components while preserving biomolecules activity. Extensive efforts are made from investigating synthesis techniques to develop novel applications over decades. In this review, the development and recent progress of various synthesis approaches are briefly summarized. In addition, its interesting properties such as adjustable porosity, excellent thermal, and chemical stabilities are introduced. Further, five representative biomedical applications are highlighted based on above physicochemical properties. Finally, the remaining challenges and offered insights into the future outlook are also discussed. This review aims to understand the co-relationships between structures and biomedical functionalities, offering the opportunity to construct attractive materials with promising characteristics.

A biomimetic nanocarrier facilitates glucose consumption and reactive oxide species accumulation in enzyme therapy for colorectal cancer

Glucose oxidase (GOx)-based enzyme therapeutics are potential alternatives for colorectal cancer (CRC) treatment via glucose consumption and accumulation of hydrogen peroxide (H2O2). Given that H2O2 can be eliminated by cytoprotective autophagy, autophagy inhibitors that can interrupt autolysosome-induced H2O2 elimination are promising combination drugs of GOx. Here, we developed a multifunctional biomimetic nanocarrier for effective co-delivery of an autophagy inhibitor-chloroquine phosphate (CQP) and GOx to exert their synergistic effect by irreversibly upregulating intracellular reactive oxygen species (ROS) levels. Poly (D, l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were used to encapsulate both GOx and CQP using a W/O/W multi-emulsion method. Calcium phosphate (CaP) was used to "fix" CQP to GOx in the internal water phase, where it served as a pH-sensitive unit to facilitate intracellular drug release. Folic acid-modified red blood cell membranes (FR) were used to camouflage the GOx/CQP/CaP encapsulated PLGA NPs (referred to as PLGA/GCC@FR). In an AOM/DSS-induced CRC mouse model, PLGA/GCC@FR exhibited improved antitumor effects, in which the number of tumor nodes were only a quarter of that in the free drug combination group. The enhanced therapeutic effects of PLGA/GCC@FR were attributed to the prolonged tumor retention which was verified by both dynamic in vivo imaging and drug biodistribution. This multifunctional biomimetic nanocarrier facilitated combined enzyme therapeutics by depleting glucose and augmenting intracellular ROS levels in tumor cells, which exerted a synergistic inhibitory effect on tumor growth. Therefore, this study proposed a novel strategy for the enhancement of combined enzyme therapeutics, which provided a promising method for effective CRC treatment.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Extensive therapeutic effects, underlying molecular mechanisms and disease treatment prediction of Metformin: a systematic review

Metformin (Met), a first-line management for type 2 diabetes mellitus, has been expansively employed and studied with results indicating its therapeutic potential extending beyond glycemic control. Beyond its established role, this therapeutic drug demonstrates a broad spectrum of action encompassing over 60 disorders, encompassing metabolic conditions, inflammatory disorders, carcinomas, cardiovascular diseases, and cerebrovascular pathologies. There is clear evidence of Met's action targeting specific nodes in the molecular pathways of these diseases and, intriguingly, interactions with the intestinal microbiota and epigenetic processes have been explored. Furthermore, novel Met derivatives with structural modifications tailored to diverse diseases have been synthesized and assessed. This manuscript proffers a comprehensive thematic review of the diseases amenable to Met treatment, elucidates their molecular mechanisms, and employs informatics technology to prospect future therapeutic applications of Met. These data and insights gleaned considerably contribute to enriching our understanding and appreciation of Met's far-reaching clinical potential and therapeutic applicability.

Effect of Petiveria alliacea Extracts on Metabolism of K562 Myeloid Leukemia Cells

Previously, studies have shown that leukemic cells exhibit elevated glycolytic metabolism and oxidative phosphorylation in comparison to hematopoietic stem cells. These metabolic processes play a crucial role in the growth and survival of leukemic cells. Due to the metabolic plasticity of tumor cells, the use of natural products has been proposed as a therapeutic alternative due to their ability to attack several targets in tumor cells, including those that could modulate metabolism. In this study, the potential of Petiveria alliacea to modulate the metabolism of K562 cell lysates was evaluated by non-targeted metabolomics. Initially, in vitro findings showed that P. alliacea reduces K562 cell proliferation; subsequently, alterations were observed in the endometabolome of cell lysates treated with the extract, mainly in glycolytic, phosphorylative, lipid, and amino acid metabolism. Finally, in vitro assays were performed, confirming that P. Alliacea extract decreased the oxygen consumption rate and intracellular ATP. These results suggest that the anti-tumor activity of the aqueous extract on the K562 cell line is attributed to the decrease in metabolites related to cell proliferation and/or growth, such as nucleotides and nucleosides, leading to cell cycle arrest. Our results provide a preliminary part of the mechanism for the anti-tumor and antiproliferative effects of P. alliacea on cancer.

Photothermal-Starvation Therapy Nanomodulator Capable of Inhibiting Colorectal Cancer Recurrence and Metastasis by Energy Metabolism Reduction

The recurrence and metastasis of colorectal cancer (CRC) have been considered as a severe challenge in clinical treatment. Recent studies have demonstrated that matrix metalloproteinases (MMPs) and lactate can promote local tumor angiogenesis, recurrence, and metastasis. The expression of MMPs is highly dependent on energy metabolism, and lactate is considered an alternative energy source for tumor proliferation and metastasis. Therefore, using a rational approach, a photothermal-starvation therapy nanomodulator that can reduce energy metabolism to suppress CRC recurrence and metastasis is designed. To design a suitable nanomodulator, glucose oxidase (GOX), indocyanine green (IR820), and α-cyano-4-hydroxycinnamic acid (CHC) into nanoparticles by a coassembly method are combined. The photothermal properties of IR820 provide the appropriate temperature and oxygen supply for the enzymatic reaction of GOX to promote intracellular glucose consumption. CHC inhibits the expression of monocarboxylate transporter 1 (MCT1), the transporter of lactic acid into cells, and also reduces oxygen consumption and promotes the GOX reaction. Additionally, altering adenosine triphosphate synthesis to block heat shock proteins expression can be an effective means to prevent IR820-mediated photothermal therapy resistance. Thus, this dual photothermal-starvation therapy nanomodulator efficiently suppresses the recurrence and metastasis of CRC by depleting intracellular nutrients.

Recent advances in glucose oxidase-based nanocarriers for tumor targeting therapy

Glucose oxidase (GOx) can specifically catalyze the conversion of β-d-glucose into gluconic acid and hydrogen peroxide (H2O2) in the presence of oxygen, making it promising for tumor starvation therapy and oxidative therapy. However, GOx's immunogenicity, poor in vivo stability, short half-life, and potential systemic toxicity, limit its application in cancer therapy. Nanocarriers are capable of improving the pharmacological properties of therapeutic drugs (e.g. stability, circulating half-life, and tumor accumulation) and lower toxicity, hence resolving GOx issues and enhancing its efficacy. Although the application of targeted nanocarriers based on GOx has recently flourished, this field has not yet been reviewed and evaluated. Herein, we initially examined the mechanism of GOx-based nanocarriers for enhanced tumor therapy. Also, we present a comprehensive and up-to-date review that highlights GOx-based nanocarriers for tumor targeting therapy. This review expands on GOx-based nano-targeted combination therapies from both passive and active targeting perspectives, meanwhile, active targeting is further classified into ligand-mediated targeting and physical-mediated targeting. Furthermore, this review also emphasizes the present challenges and promising advancements.

Repurposing drugs targeting metabolic diseases for cancer therapeutics

Hurdles in the identification of new drugs for cancer treatment have made drug repurposing an increasingly appealing alternative. The approach involves the use of old drugs for new therapeutic purposes. It is cost-effective and facilitates rapid clinical translation. Given that cancer is also considered a metabolic disease, drugs for metabolic disorders are being actively repurposed for cancer therapeutics. In this review, we discuss the repurposing of such drugs approved for two major metabolic diseases, diabetes and cardiovascular disease (CVD), which have shown potential as anti-cancer treatment. We also highlight the current understanding of the cancer signaling pathways that these drugs target.

m6A-regulated tumor glycolysis: new advances in epigenetics and metabolism

Glycolytic reprogramming is one of the most important features of cancer and plays an integral role in the progression of cancer. In cancer cells, changes in glucose metabolism meet the needs of self-proliferation, angiogenesis and lymphangiogenesis, metastasis, and also affect the immune escape, prognosis evaluation and therapeutic effect of cancer. The n6-methyladenosine (m6A) modification of RNA is widespread in eukaryotic cells. Dynamic and reversible m6A modifications are widely involved in the regulation of cancer stem cell renewal and differentiation, tumor therapy resistance, tumor microenvironment, tumor immune escape, and tumor metabolism. Lately, more and more evidences show that m6A modification can affect the glycolysis process of tumors in a variety of ways to regulate the biological behavior of tumors. In this review, we discussed the role of glycolysis in tumor genesis and development, and elaborated in detail the profound impact of m6A modification on different tumor by regulating glycolysis. We believe that m6A modified glycolysis has great significance and potential for tumor treatment.

Enhanced apoptosis of HCT116 colon cancer cells treated with extracts from Calotropis gigantea stem bark by starvation

Calotropis gigantea stem bark extract, particularly the dichloromethane fraction (CGDCM), demonstrated the most potent antiproliferative effects on hepatocellular carcinoma HepG2 and colorectal HCT116 cells. The current study focused on enhancing the effectiveness of cancer treatment with CGDCM at concentrations close to the IC50 in HCT116 cells by reducing their nutrient supply. CGDCM (2, 4, and 8 μg/mL) treatment for 24 h under glucose conditions of 4.5 g/L without fetal bovine serum (FBS) supplementation or serum starvation (G+/F-), glucose 0 g/L with 10% FBS or glucose starvation (G-/F+), and glucose 0 g/L with 0% FBS or complete starvation (G-/F-) induced a greater antiproliferative effect in HCT116 cells than therapy in complete medium with glucose 4.5 g/L and 10% FBS (G+/F+). Nonetheless, the anticancer effect of CGDCM at 4 μg/mL under (G-/F-) showed the highest activity compared to other starvation conditions. The three starvation conditions showed a significant reduction in cell viability compared to the control (G+/F+) medium group, while the inhibitory effect on cell viability did not differ significantly among the three starvation conditions. CGDCM at 4 μg/mL in (G-/F-) medium triggered apoptosis by dissipating the mitochondrial membrane potential and arresting cells in the G2/M phase. This investigation demonstrated that a decrease in intracellular ATP and fatty acid levels was associated with enhanced apoptosis by treatment with CGDCM at 4 μg/mL under (G-/F-) conditions. In addition, under (G-/F-), CGDCM at 4 μg/mL increased levels of reactive oxygen species (ROS) and was suggested to primarily trigger apoptosis in HCT116 cells. Thus, C. gigantea extracts may be useful for the future development of alternative, effective cancer treatment regimens.

The "sweet" path to cancer: focus on cellular glucose metabolism

The hypoxia-inducible factor-1α (HIF-1α), a key player in the adaptive regulation of energy metabolism, and the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2), a critical regulator of glucose consumption, are the main drivers of the metabolic rewiring in cancer cells. The use of glycolysis rather than oxidative phosphorylation, even in the presence of oxygen (i.e., Warburg effect or aerobic glycolysis), is a major metabolic hallmark of cancer. Aerobic glycolysis is also important for the immune system, which is involved in both metabolic disorders development and tumorigenesis. More recently, metabolic changes resembling the Warburg effect have been described in diabetes mellitus (DM). Scientists from different disciplines are looking for ways to interfere with these cellular metabolic rearrangements and reverse the pathological processes underlying their disease of interest. As cancer is overtaking cardiovascular disease as the leading cause of excess death in DM, and biological links between DM and cancer are incompletely understood, cellular glucose metabolism may be a promising field to explore in search of connections between cardiometabolic and cancer diseases. In this mini-review, we present the state-of-the-art on the role of the Warburg effect, HIF-1α, and PKM2 in cancer, inflammation, and DM to encourage multidisciplinary research to advance fundamental understanding in biology and pathways implicated in the link between DM and cancer.

"Domino" cascade reactor based on DNA hydrogel for synergistic treatment of malignant tumor

The action pathways of starvation therapy and photodynamic therapy (PDT) do not exist in isolation and are usually related to tumor cell metabolism and immune regulation, which are of great significance in the treatment of malignant tumors. Here, a cancer-targeted "domino" cascade reactor is constructed for synergistic starvation therapy and amplifies photodynamic therapy by assembling hemin and glucose oxidase (GOx) into DNA hydrogel load with hypoxia-inducible factor 1α (HIF-1α) and photosensitizer chlorin e6 (Ce6). The cascade reactor has excellent biocompatibility and tumor targeting, which promotes PDT by reducing HIF-1α. At the same time, the G-quadruplex of AS1411 combined with hemin (AH) catalyzes the generation of oxygen from hydrogen peroxide to further improve the efficiency of PDT. The synergistic therapeutic effect of the cascade reactor is evaluated through in vivo and in vitro experiments, indicating that this cascade reactor has great potential advantages in the synergistic treatment of cancer.

Dual-Functional Nanoplatform Based on Bimetallic Metal-Organic Frameworks for Synergistic Starvation and Chemodynamic Therapy

Tumor microenvironment (TME)-responsive chemodynamic therapy (CDT) mediated by nanozymes has been extensively studied in oral squamous cell carcinoma. However, the low catalytic efficiency due to insufficient H₂O₂ in the TME is still a major challenge for its clinical translation. Herein, we present an antitumor nanoplatform based on a Mn-Co organometallic framework material (MnCoMOF), which shows peroxidase-like (POD-like) activity, loaded with glucose oxidase (GOx@MnCoMOF), demonstrating the ability of H₂O₂ self-supply and H₂O₂ conversion to toxic hydroxyl radicals. The encapsulated GOx efficiently catalyzes glucose into gluconic acid and H₂O₂ at the tumor site, which can cut off the energy supply to inhibit tumor growth and produce a large amount of H₂O₂ and acid to compensate for their lack in the tumor microenvironment. The POD-like activity of MnCoMOF can convert H₂O₂ into hydroxyl radicals and eliminate tumor cells. The nanoplatform exhibits enhanced tumor cell cytotoxicity in a high-glucose medium compared with a low-glucose medium, illustrating sufficient generation of H₂O₂ from glucose by GOx. The in vivo results indicate that GOx@MnCoMOF has excellent antitumor efficacy and can remodel the immune-suppressive tumor microenvironment. In conclusion, the GOx@MnCoMOF nanoplatform possesses dual enzymatic activities, i.e., POD-like and glucose oxidase, to achieve improved tumor-suppressive efficiency through synergistic starvation and chemodynamic therapy, thus providing a new strategy for the clinical treatment of oral cancer.

Nano-baicalein facilitates chemotherapy in breast cancer by targeting tumor microenvironment

Cancer-associated fibroblasts constitute a significant component in the tumor microenvironment, playing a pivotal role in tumor proliferation, invasion, migration, and metastasis. Consequently, therapy combining chemotherapeutic agents with tumor microenvironment (TME) modulators appears to be a promising avenue for cancer treatment. In this paper, a tumor microenvironment-based mPEG-PLGA nanoparticle loaded with baicalein (PMs-Ba) was constructed for the purpose of improving the tumor microenvironment in cases of triple-negative breast cancer. The results demonstrate that, on the one hand, PMs-Ba was able to inhibit the transforming growth factor β(TGF-β) signaling pathway to avoid the activation of cancer-associated fibroblasts (CAFs), thereby influencing the interstitial microenvironment of the tumor. On the other hand, the agent led to an increase in the infiltration of cytotoxic T cells, activating the tumor immune microenvironment. Meanwhile, in the murine breast cancer model, an intravenous injection of PMs-Ba combined with doxorubicin nanoparticles (PMs-ADM) significantly improved the antitumor effectiveness. These results suggest that baicalein encapsulated in nanoparticles may be a promising strategy for modulating the TME and for adjuvant chemotherapy, signifying a potential TME-remodeling nanoformulation that could enhance the antitumor efficacy of nanotherapeutics.

Biomimetic Nanoplatform with H2O2 Homeostasis Disruption and Oxidative Stress Amplification for Enhanced Chemodynamic Therapy

Chemodynamic therapy (CDT) is a powerful cancer treatment strategy by producing excessive amount of reactive oxygen species (ROS) to kill cancer cells. However, the inadequate hydrogen peroxide (H₂O₂) supply and antioxidant defense systems in tumor tissue significantly impair the therapeutic effect of CDT, hindering its further applications. Herein, we present an intelligent nanoplatform with H₂O₂ homeostasis disruption and oxidative stress amplification properties for enhanced CDT. This nanoplatform is obtained by encapsulating glucose oxidase (GOx) in a pH- and glutathione (GSH)-responsive degradable copper doped-zeolitic imidazolate framework (Cu-ZIF8), followed by loading of 3-amino-1,2,4-triazole (3AT) and modification of hyaluronic acid (HA) for tumor targeting delivery. The GOx@Cu-ZIF8-3AT@HA not only reduces energy supply and increases H₂O₂ level by exhausting intratumoral glucose, but also disturbs tumor antioxidant defense systems by inhibiting the activity of catalase and depleting intracellular GSH, resulting in disrupted H₂O₂ homeostasis in tumor. Moreover, the elevated H₂O₂ will transform into highly toxic •OH by Cu⁺ that generated from redox reaction between Cu²⁺ and GSH, amplifying the oxidative stress to enhance the CDT efficacy. Consequently, GOx@Cu-ZIF8-3AT@HA has significantly inhibited the 4T1 xenograft tumor growth without discernible side effects, which provides a promising strategy for cancer management. STATEMENT OF SIGNIFICANCE: The inadequate hydrogen peroxide (H₂O₂) level and antioxidant defense system in tumor tissues significantly impair the therapeutic effect of chemodynamic therapy (CDT). Herein, we developed an intelligent nanoplatform with H₂O₂ homeostasis disruption and oxidative stress amplification properties for enhanced CDT. In this nanoplatform, glucose oxidase (GOx) could exhaust intratumoral glucose to reduce energy supply accompanied with production of H₂O₂, while the suppression of catalase activity by 3-amino-1,2,4-triazole (3AT) and depletion of glutathione by Cu²⁺ would weaken the antioxidant defense system of tumors. Ultimately, the raised H₂O₂ level would convert to highly toxic hydroxyl radical (•OH) by Fenton-like reaction, amplifying the CDT efficacy. This work provides a promising strategy for cancer management.

An enzyme-instructed self-assembly system induces tumor acidosis via sequential-dual effect for cancer selective therapy

The acidosis anti-tumor therapy, based on the altered energy metabolism pathway of tumor cells, has been proposed as an attractive method for cancer selective treatment. However, the strategy of inducing tumor acidosis by using a single drug to simultaneously inhibit both lactate efflux and consumption has not been reported yet. Herein, an in situ enzyme-instructed self-assembly (EISA) system was rationally fabricated to induce tumor acidosis apoptosis for cancer selective therapy. Depending on the sequential effect of the in situ EISA system, the targeted drug was successively distributed on the membrane and intracellular, inhibiting MCT4 mediated lactate efflux and mitochondrial tricarboxylic acid (TCA) cycle mediated lactate consumption, respectively. Through the dual obstruction of lactate metabolism to trigger tumor acidosis, the in situ EISA nanomedicine showed selective growth and migration inhibition against cancer cells. In addition, the nanomedicine also displayed a radio-sensitization effect in vitro due to causing the mitochondrial dysfunction, and exhibited a prominent synergistic chemo-radiotherapy anti-tumor performance in vivo. Accordingly, this work demonstrated that the in situ EISA system could endow the LND with sequential-dual effects to induce tumor acidosis, which may provide an enlightening strategy for anticancer drug delivery and cancer selective therapy. STATEMENT OF SIGNIFICANCE: With the help of the sequential effect of in situ EISA, the serial attack of LND against different targets was effectively realized to induce tumor acidosis and combined chemo-radiotherapy, implying the importance of the relationship between structure and function, which could offer a distinctive inspiration for future drug delivery system design and anti-tumor application.

Enhancing the therapeutic efficacy of nanoparticles for cancer treatment using versatile targeted strategies

Poor targeting of therapeutics leading to severe adverse effects on normal tissues is considered one of the obstacles in cancer therapy. To help overcome this, nanoscale drug delivery systems have provided an alternative avenue for improving the therapeutic potential of various agents and bioactive molecules through the enhanced permeability and retention (EPR) effect. Nanosystems with cancer-targeted ligands can achieve effective delivery to the tumor cells utilizing cell surface-specific receptors, the tumor vasculature and antigens with high accuracy and affinity. Additionally, stimuli-responsive nanoplatforms have also been considered as a promising and effective targeting strategy against tumors, as these nanoplatforms maintain their stealth feature under normal conditions, but upon homing in on cancerous lesions or their microenvironment, are responsive and release their cargoes. In this review, we comprehensively summarize the field of active targeting drug delivery systems and a number of stimuli-responsive release studies in the context of emerging nanoplatform development, and also discuss how this knowledge can contribute to further improvements in clinical practice.