The Complex Interplay between Antioxidants and ROS in Cancer

Copper Drives Remodeling of Metabolic State and Progression of Clear Cell Renal Cell Carcinoma

SIGNIFICANCE

The work establishes a requirement for glucose-dependent coordination between energy production and redox homeostasis, which is fundamental for the survival of cancer cells that accumulate Cu and contributes to tumor growth.

Nano-Based Strategies Aiming at Tumor Microenvironment for Improved Cancer Therapy

Malignant tumors pose a considerable threat to human life and health. Traditional treatments, such as radiotherapy and chemotherapy, often lack specificity, leading to collateral damage to normal tissues. Tumor microenvironment (TME) is characterized by hypoxia, acidity, redox imbalances, and elevated ATP levels factors that collectively promote tumor growth and metastasis. This review provides a comprehensive overview of the nanoparticles developed in recent years for TME-responsive strategies or TME-modulating methods for tumor therapy. The TME-responsive strategies focus on designing and synthesizing nanoparticles that can interact with the tumor microenvironment to achieve precisely controlled drug release. These nanoparticles activate drug release under specific conditions within the tumor environment, thereby enhancing the efficacy of the drugs while reducing toxicity to normal cells. Moreover, simply eliminating tumor cells does not fundamentally solve the problem. Only by comprehensively regulating the TME to make it unsuitable for tumor cell survival and proliferation can we achieve more thorough therapeutic effects and reduce the risk of tumor recurrence. TME regulation strategies aim to suppress the growth and metastasis of tumor cells by modulating various components within the TME. These strategies not only improve treatment outcomes but also have the potential to lay the foundation for future personalized cancer therapies.

A multi-functional integrated nanoplatform based on a tumor microenvironment-responsive PtAu/MnO2 cascade nanoreactor with multi-enzymatic activities for multimodal synergistic tumor therapy

The utilization or improvement of tumor microenvironment (TME) has become a breakthrough in emerging oncology therapies. To address the limited therapeutic efficacy of single modality, a multi-functional integrated nanoplatform based on a TME-responsive PtAu/MnO2 cascade nanoreactor with multi-enzymatic activities was developed for multimodal synergistic tumor therapy. Benefiting from the slightly acidic environment and high-level glutathione (GSH) in TME, PtAu/MnO2 cascade nanoreactor consumed GSH, followed by the reductive generation of manganese ion (Mn2+) and the release of PtAu nanoparticles (NPs). Then, the multimodal synergistic tumor therapy was activated as follows. First, GSH depletion inhibited the activity of glutathione peroxidase 4 and led to the accumulation of lipid peroxidation, thereby inducing tumor cell ferroptosis. Second, PtAu NPs exhibited catalase-like, glucose oxidase-like and nicotinamide adenine dinucleotide (NADH) oxidase-like activities, which generated oxygen for the cascade reaction to alleviate hypoxia and further depleted glucose, NADH and adenosine triphosphate, leading to the inhibition of tumor cell proliferation via starvation therapy. Third, the production of reactive oxygen species by the oxidase- and peroxidase-like activities of PtAu NPs and the Fenton-like reaction of Mn2+ simultaneously induced tumor cell apoptosis via chemodynamic therapy. Briefly, the in vitro and in vivo results confirmed that the multi-functional integrated nanoplatform based on a PtAu/MnO2 cascade nanoreactor with five nanozyme activities demonstrated outstanding biocompatibility and greater inhibition of tumor growth via synergistic ferroptosis/starvation therapy/apoptosis.

The interplay between doxorubicin chemotherapy, antioxidant system, and cardiotoxicity: Unrevealing of the protective potential of tannic acid

Cardiotoxicity is the leading side effect of anthracycline-based chemotherapy. Therefore, it has gained importance to reveal chemotherapy-supporting strategies and reliable agents with their mechanisms of action. Tannic acid (TA), a naturally occurring plant polyphenol, has diverse physiological effects, including anti-inflammatory, anticarcinogenic, antioxidant, and radical scavenging properties. Therefore, this study was designed to investigate whether TA exerts a protective effect on mechanisms contributing to anthracycline-induced cardiotoxicity in rat heart tissues exposed to doxorubicin (DOX). Rats were randomly divided into control and experimental groups and treated with (18 mg/kg) DOX, TA (50 mg/kg), and DOX + TA during the 2 weeks. Cardiac gene markers and mitochondrial DNA (mtDNA) content were evaluated in the heart tissues of all animals. In addition to major metabolites, mRNA expression changes and biological activity responses of components of antioxidant metabolism were examined in the heart tissues of all animals. The expression of cardiac gene markers increased by DOX exposure was significantly reduced by TA treatment, whereas mtDNA content, which was decreased by DOX exposure, was significantly increased. TA also improved antioxidant metabolism members' gene expression and enzymatic activity, including glutathione peroxidase, glutathione s-transferase, superoxide dismutase, catalase, and thioredoxin reductase. This study provides a detailed overview of the current understanding of DOX-induced cardiotoxicity and preventive or curative measures involving TA.

Ferroptosis: A novel cell death modality as a synergistic therapeutic strategy with photodynamic therapy

Although there has been significant progress in current comprehensive anticancer treatments centered on surgery, postoperative recurrence and tumor metastasis still significantly affect both prognosis and quality of life of the patient. Hence, the development of precisely targeted tumor therapies and exploration of immunotherapy represent additional strategies for tumor treatment. Photodynamic therapy (PDT) is a relatively safe treatment modality that not only induces multiple modes of tumor cell death but also mediates the secondary immunological responses against tumor resistance and metastasis. Ferroptosis, an iron-dependent type of programmed cell death characterized by accumulation of reactive oxygen species and lipid peroxidation products to lethal levels, has emerged as an attractive target trigger for tumor therapies. Recent research has revealed a close association between PDT and ferroptosis, suggesting that combining ferroptosis inducers with PDT could strengthen their synergistic anti-tumor efficiency. Here in this review, we discuss the rationale for combining PDT with ferroptosis inducers and highlight the progress of single-molecule photosensitizers to induce ferroptosis, as well as the applications of photosensitizers combined with other therapeutic drugs for collaborative therapy. Furthermore, given the current research dilemma, we propose potential therapeutic strategies to advance the combined usage of PDT and ferroptosis inducers, providing the basis and guidelines for prospective clinical translation and research directionality with regard to PDT.

2D Janus carrier-enabled trojan horse: Gallium delivery for the sequential therapy of biofilm associated infection

Biofilm-associated infections (BAIs) continue to pose a major challenge in the medical field. Nanomedicine, in particular, promises significant advances in combating BAIs through the introduction of a variety of nanomaterials and nano-antimicrobial strategies. However, studies to date have primarily focused on the removal of the bacterial biofilm and neglect the subsequent post-biofilm therapeutic measures for BAIs, rendering pure anti-biofilm strategies insufficient for the holistic recovery of affected patients. Herein, we construct an emerging dual-functional composite nanosheet (SiHx@Ga) that responds to pHs fluctuation in the biofilm microenvironment to enable a sequential therapy of BAIs. In the acidic environment of biofilm, SiHx@Ga employs the self-sensitized photothermal Trojan horse strategy to effectively impair the reactive oxygen species (ROS) defense system while triggering oxidative stress and lipid peroxidation of bacteria, engendering potent antibacterial and anti-biofilm effects. Surprisingly, in the post-treatment phase, SiHx@Ga adsorbs free pathogenic nucleic acids released after biofilm destruction, generates hydrogen with ROS-scavenging and promotes macrophage polarization to the M2 type, effectively mitigating damaging inflammatory burst and promoting tissue healing. This well-orchestrated strategy provides a sequential therapy of BAIs by utilizing microenvironmental variations, offering a conceptual paradigm shift in the field of nanomedicine anti-infectives.

An imidazo-pyridin derivative as fluorescent probe for the peroxynitrite detection in pulmonary permissive hypercapnia

The physiological and pathological processes in lungs indicated that ONOO- acted as an informative indicator for pulmonary functioning status with the corresponding dynamics, especially in permissive hypercapnia. Herein, for the peroxynitrite (ONOO-) detection and imaging in living lung cells, an imidazo-pyridin derived fluorescent probe IDPD-ONOO was developed. IDPD-ONOO recognized ONOO- to exhibit a corresponding fluorescence response at 490 nm with the excitation wavelength at 355 nm. The advantages of the developed probe included practical linear range (0-100 μM), high sensitivity (Limit of Detection 0.005 μM), rapid response (within 15 min), pH tolerance (7.0-9.0), high selectivity, and low cyto-toxicity. Furthermore, IDPD-ONOO achieved the pulmonary intracellular imaging of both the exogenous and endogenous ONOO- level, which was meaningful for the research on the pulmonary physiological and pathological mechanism with optimized optical implements.

Synergistic Ultrasound-Activable Artificial Enzyme and Precision Gene Therapy to Suppress Redox Homeostasis and Malignant Phenotypes for Controllably Combating Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains one of the most lethal malignant tumors. Multimodal therapeutics with synergistic effects for treating HCC have attracted increasing attention, for instance, designing biocompatible porphyrin-based nanomedicines for enzyme-mimetic and ultrasound (US)-activable reactive oxygen species (ROS) generation. Despite the promise, the landscape of such advancements remains sparse. Here, we propose the de novo design of a π-conjugated, osmium (Os)-coordinated polyporphyrin (P-Por-Os) nanovesicle to serve as an ultrasound-activable artificial enzyme for synergistic therapies to suppress redox homeostasis and malignant phenotypes for controllably combating HCC. Our findings reveal that the P-Por-Os with US showed superior, multifaceted, and controllable ROS-generating activities. This system not only subverts the redox balance within HCC cells but also achieves precise and controlled tumor ablation at remarkably low concentrations, as evidenced across cellular assays and animal models. In the liver orthotopic model, US not only activates the artificial enzyme to catalyze ROS but also facilitates remote-controlled ablation of HCC through precise US positioning. Moreover, the P-Por-Os + US can assist the precision gene therapy by knocking down the ROS resistance factor, MT2A, and down-regulating its downstream oncogene IGFBP2 to attenuate ROS resistance, proliferation, and migration of HCC efficiently. We suggest that the design of this ultrasound-activable artificial enzyme presents a promising avenue for the engineering of innovative tumoricidal materials, offering a synergistic therapeutic approach with high biosecurity for HCC treatment.

A histochemical approach to activity-based copper sensing reveals cuproplasia-dependent vulnerabilities in cancer

Copper is an essential nutrient for sustaining vital cellular processes spanning respiration, metabolism, and proliferation. However, loss of copper homeostasis, particularly misregulation of loosely bound copper ions which are defined as the labile copper pool, occurs in major diseases such as cancer, where tumor growth and metastasis have a heightened requirement for this metal. To help decipher the role of copper in the etiology of cancer, we report a histochemical activity-based sensing approach that enables systematic, high-throughput profiling of labile copper status across many cell lines in parallel. Coppermycin-1 reacts selectively with Cu(I) to release puromycin, which is then incorporated into nascent peptides during protein translation, thus leaving a permanent and dose-dependent marker for labile copper that can be visualized with standard immunofluorescence assays. We showcase the utility of this platform for screening labile Cu(I) pools across the National Cancer Institute's 60 (NCI-60) human tumor cell line panel, identifying cell types with elevated basal levels of labile copper. Moreover, we use Coppermycin-1 to show that lung cancer cells with heightened activation of nuclear factor-erythroid 2-related factor 2 (NRF2) possess lower resting labile Cu(I) levels and, as a result, have reduced viability when treated with a copper chelator. This work establishes that methods for labile copper detection can be used to assess cuproplasia, an emerging form of copper-dependent cell growth and proliferation, providing a starting point for broader investigations into the roles of transition metal signaling in biology and medicine.

Exploring Strategies to Prevent and Treat Ovarian Cancer in Terms of Oxidative Stress and Antioxidants

Oxidative stress is a state of imbalance between the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and the antioxidant defence system in the body. Oxidative stress may be associated with a variety of diseases, such as ovarian cancer, diabetes mellitus, and neurodegeneration. The generation of oxidative stress in ovarian cancer, one of the common and refractory malignancies among gynaecological tumours, may be associated with several factors. On the one hand, the increased metabolism of ovarian cancer cells can lead to the increased production of ROS, and on the other hand, the impaired antioxidant defence system of ovarian cancer cells is not able to effectively scavenge the excessive ROS. In addition, chemotherapy and radiotherapy may elevate the oxidative stress in ovarian cancer cells. Oxidative stress can cause oxidative damage, promote the development of ovarian cancer, and even result in drug resistance. Therefore, studying oxidative stress in ovarian cancer is important for the prevention and treatment of ovarian cancer. Antioxidants, important markers of oxidative stress, might serve as one of the strategies for preventing and treating ovarian cancer. In this review, we will discuss the complex relationship between oxidative stress and ovarian cancer, as well as the role and therapeutic potential of antioxidants in ovarian cancer, thus guiding future research and clinical interventions.

Polymethoxylated flavone variations and in vitro biological activities of locally cultivated Citrus varieties in China

Citrus peels are rich in polymethoxylated flavones (PMFs), which have beneficial health and pharmacological properties. In this study, the profiles, variations, and biological activities of PMFs in the peel extracts of 27 Citrus varieties (eight species) native to China were investigated. UPLC-QTOF-MS/MS analysis revealed that mandarin accumulated more diversity and higher detectable PMF contents. Wangcangzhoupigan (ZPG) possessed the highest antioxidant capacity. Gailiangcheng (GLC) and Bingtangcheng (BTC), sweet oranges showed excellent inhibitory effects against pancreatic lipase and α-glucosidase, respectively. Most citrus extracts effectively inhibited the production of ROS and pro-inflammatory cytokines, while increasing the accumulation of anti-inflammatory cytokines. In addition, Limeng (LM), Cupig-oushigan (GSG), and Yanxiwanlu (YXWL) showed anti-proliferative effects against DU145 and PC3 cancer cells. This study provides a comprehensive PMF profile and biological activities of various citrus species and will benefit future functional citrus breeding practices aimed at designing plants rich in total or specific PMFs for health benefits.

Rhodoquinone carries electrons in the mammalian electron transport chain

Ubiquinone (UQ), the only known electron carrier in the mammalian electron transport chain (ETC), preferentially delivers electrons to the terminal electron acceptor oxygen (O2). In hypoxia, ubiquinol (UQH2) diverts these electrons onto fumarate instead. Here, we identify rhodoquinone (RQ), an electron carrier detected in mitochondria purified from certain mouse and human tissues that preferentially delivers electrons to fumarate through the reversal of succinate dehydrogenase, independent of environmental O2 levels. The RQ/fumarate ETC is strictly present in vivo and is undetectable in cultured mammalian cells. Using genetic and pharmacologic tools that reprogram the ETC from the UQ/O2 to the RQ/fumarate pathway, we establish that these distinct ETCs support unique programs of mitochondrial function and that RQ confers protection upon hypoxia exposure in vitro and in vivo. Thus, in discovering the presence of RQ in mammals, we unveil a tractable therapeutic strategy that exploits flexibility in the ETC to ameliorate hypoxia-related conditions.

Enhanced Anticancer Efficacy of Alkaline Plasma-Activated Water through Augmented RONS Production

Despite notable advances in anticancer drug development, their manufacture and use pose environmental and health risks due to toxic byproducts, drug residue contamination, and cytotoxicity to normal cells. Therefore, developing cost-effective anticancer treatments with fewer toxic side effects and higher selectivity is essential to the advancement of highly effective anticancer therapies. Plasma-activated water (PAW) offers a green alternative to conventional chemical treatments as it reverts to water within days. However, the limited duration and dose of reactive oxygen and nitrogen species (RONS) in acidified PAW restrict its clinical deployment and the full understanding of their mechanism. In this study, we propose alkaline PAW as an innovative enhancement of the RONS technology. The alkaline PAW generated markedly superior RONS, with about 10 times higher levels of NO2-, H2O2, and ONOO-/O2•- than acidic PAW. The possible RONS generation pathways in alkaline PAW are analyzed by scavengers. In conventional acidic PAW, 70% of the H2O2 concentration is contributed by •OH but only about 20% in alkaline PAW. ONOO- is mainly formed through the reaction of O2•- with NO in alkaline pH, while in acidic PAW, it mainly forms from NO2- and H2O2. The results unveiled the synergistic and formidable anticancer effects of alkaline PAW against cancer cells, typified by an increase in intracellular ROS/RNS levels. Furthermore, alkaline PAW injection also effectively prevented xenograft tumor growth in mice. We systematically investigated this high-dose anticancer solution without using noble gases, toxic reagents, or extra energy consumption and successfully demonstrated the possibility of alkaline PAW being an effective and environmentally friendly therapeutic technology. The activity is closely linked to the RONS dose, and the generation pathway provides much-needed insight into the fundamental aspects of PAW chemistry required for the optimization of the biochemical activity of PAW.

Mechanisms and therapeutic potential of disulphidptosis in cancer

SLC7A11 plays a pivotal role in tumour development by facilitating cystine import to enhance glutathione synthesis and counteract oxidative stress. Disulphidptosis, an emerging form of cell death observed in cells with high expression of SLC7A11 under glucose deprivation, is regulated through reduction-oxidation reactions and disulphide bond formation. This process leads to contraction and collapse of the F-actin cytoskeleton from the plasma membrane, ultimately resulting in cellular demise. Compared to other forms of cell death, disulphidptosis exhibits distinctive characteristics and regulatory mechanisms. This mechanism provides novel insights and innovative strategies for cancer treatment while also inspiring potential therapeutic approaches for other diseases. Our review focuses on elucidating the molecular mechanism underlying disulphidptosis and its connection with the actin cytoskeleton, identifying alternative metabolic forms of cell death, as well as offering insights into disulphidptosis-based cancer therapy. A comprehensive understanding of disulphidptosis will contribute to our knowledge about fundamental cellular homeostasis and facilitate the development of groundbreaking therapies for disease treatment.

Metabolic Reprogramming in Cancer: Implications for Immunosuppressive Microenvironment

Cancer is a complex and heterogeneous disease characterised by uncontrolled cell growth and proliferation. One hallmark of cancer cells is their ability to undergo metabolic reprogramming, which allows them to sustain their rapid growth and survival. This metabolic reprogramming creates an immunosuppressive microenvironment that facilitates tumour progression and evasion of the immune system. In this article, we review the mechanisms underlying metabolic reprogramming in cancer cells and discuss how these metabolic alterations contribute to the establishment of an immunosuppressive microenvironment. We also explore potential therapeutic strategies targeting metabolic vulnerabilities in cancer cells to enhance immune-mediated anti-tumour responses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02044861, NCT03163667, NCT04265534, NCT02071927, NCT02903914, NCT03314935, NCT03361228, NCT03048500, NCT03311308, NCT03800602, NCT04414540, NCT02771626, NCT03994744, NCT03229278, NCT04899921.

ALDH1L2 drives HCC progression through TAM polarization

Background & Aims

Dysregulation of one-carbon metabolism is considered an early hallmark of mitochondrial dysfunction and cancer metabolism. ALDH1L2 belongs to the aldehyde dehydrogenase family and plays an important role in tumor progression. However, little is known about the precise role and underlying mechanisms of ALDH1L2 in hepatocellular carcinoma (HCC).

Methods

Immunohistochemistry, western blotting, and immunofluorescence staining were used to evaluate ALDH1L2 expression in HCC samples (n = 90) and cell lines (n = 9). A series of in vitro and in vivo assays were performed to explore the role and molecular mechanism of ALDH1L2 in HCC progression.

Results

ALDH1L2 upregulation is associated with poor prognosis in HCC (hazard ratio 1.923; 95% confidence interval 1.03-3.59; p = 0.04). ALDH1L2 promotes tumor cell proliferation and metastasis by activating NRF2/IL-6/STAT3 signaling. ALDH1L2 promotes mitochondrial respiration, increases ATP production and protects HCC cells from reactive oxygen species-induced cellular damage via NRF2 stabilization. NRF2 also directly binds to the ALDH1L2 promoter and increases ALDH1L2 transcription, thereby establishing a positive feedback loop to maintain the function of ALDH1L2. The interaction between tumor-associated macrophages and ALDH1L2-overexpressing HCC cells further promotes HCC progression. In addition, ALDH1L2 knockdown enhances the anti-HCC activity of the tyrosine kinase inhibitor sorafenib.

Conclusions

These findings provide the first evidence indicating that ALDH1L2 is directly involved in tumor progression by interacting with tumor-associated macrophages through the Jak2/STAT3 signaling pathway and that ALDH1L2 may be a target molecule for HCC therapy.

Impact and implications

This research highlights that ALDH1L2 could serve as a predictive and prognostic marker in HCC. We found that a positive feedback loop between ALDH1L2 and NRF2 promotes HCC progression by activating the IL-6/Jak2/STAT3 signaling axis and tumor-associated macrophage polarization. In addition, we found that ALDH1L2 knockdown enhances the anti-HCC effect of sorafenib.

Tumor Metabolic Reprogramming and Ferroptosis: The Impact of Glucose, Protein, and Lipid Metabolism

Ferroptosis, a novel form of cell death discovered in recent years, is typically accompanied by significant iron accumulation and lipid peroxidation during the process. This article systematically elucidates how tumor metabolic reprogramming affects the ferroptosis process in tumor cells. The paper outlines the basic concepts and physiological significance of tumor metabolic reprogramming and ferroptosis, and delves into the specific regulatory mechanisms of glucose metabolism, protein metabolism, and lipid metabolism on ferroptosis. We also explore how complex metabolic changes in the tumor microenvironment further influence the response of tumor cells to ferroptosis. Glucose metabolism modulates ferroptosis sensitivity by influencing intracellular energetic status and redox balance; protein metabolism, involving amino acid metabolism and protein synthesis, plays a crucial role in the initiation and progression of ferroptosis; and the relationship between lipid metabolism and ferroptosis primarily manifests in the generation and elimination of lipid peroxides. This review aims to provide a new perspective on how tumor cells regulate ferroptosis through metabolic reprogramming, with the ultimate goal of offering a theoretical basis for developing novel therapeutic strategies targeting tumor metabolism and ferroptosis.

From Bench to Bedside: ROS-Responsive Nanocarriers in Cancer Therapy

Reactive oxygen species (ROS) play a dual role in cancer, acting as both signaling molecules that promote tumour growth and as agents that can inhibit tumour progression through cytotoxic effects. In cancer therapy, ROS-responsive drug delivery systems take advantage of the elevated ROS levels found in tumors compared to healthy tissues. These systems are engineered to release drugs precisely in response to increased ROS levels in tumour cells, allowing targeted and controlled treatment, minimizing side effects, and enhancing therapeutic outcomes. ROS generation in cancer cells is linked to metabolic changes, mitochondrial dysfunction, and oncogenic signaling, leading to increased oxidative stress. Tumour cells manage this by upregulating antioxidant defenses to prevent ROS from reaching harmful levels. This balance between ROS production and neutralization is critical for cancer cell survival, making ROS both a challenge and an opportunity for targeted therapies. ROS also connect inflammation and cancer. Chronic inflammation leads to elevated ROS, which can damage DNA and proteins, promoting mutations and cancer development. Additionally, ROS contribute to protein degradation, affecting essential cellular functions. Therapeutic strategies targeting ROS aim to either increase ROS beyond tolerable levels for cancer cells or inhibit their antioxidant defenses. Nanocarriers responsive to ROS show great potential in improving the precision of cancer treatments by releasing drugs specifically in high ROS environments, like tumors. This review discusses the mechanisms of ROS in cancer, its role in inflammation and protein degradation, and the advances in ROS-targeted nanocarrier therapies across different cancer types.

Current status of serum metabolites biomarkers for polyps and colorectal cancer: a systematic review

Background

Early detection of colorectal cancer (CRC) is crucial to enhance the disease treatment and prognosis of patients. Colonoscopy remains the gold standard for CRC detection; however, it requires trained personnel with expensive tools. Currently, serum metabolites have been discovered to be used to discriminate patients with polyps and CRC. This study aimed to identify the most commonly detected predictive serum metabolites for polyps and CRC.

Methods

A systematic search of the Web of Science, PubMed, and Cochrane Library databases was conducted using PRISMA guidelines. Ten studies investigating serum metabolite biomarkers of CRC and polyps using different analytical platforms and study populations were included. QUADOMICS tool was used to analyse the quality of the included studies. All reported metabolites were then enriched into the pathways using MetaboAnalyst 5.0.

Results

We found that several potential signature metabolites overlapped between studies, including tyrosine, lysine, cystine, arabinose, and lactate for CRC and lactate and glutamate for polyps. The most affected pathways related to CRC were the urea cycle, glutathione metabolism, purine metabolism, glutamate metabolism, and ammonia recycling. In contrast, those affected in the polyps were the urea cycle, glutamate metabolism, glutathione metabolism, arginine and proline metabolism, and carnitine synthesis.

Conclusions

This review has found commonly detected serum metabolites for polyps and CRC with huge potential to be used in clinical settings. However, the differences between altered pathways in polyps and CRC, other external factors, and their effects on the regulation level, sensitivity, and specificity of each identified metabolite remained unclear, which could benefit from a further extensive cohort study and well-defined analysis equipment.

Antibodies Against Anti-Oxidant Enzymes in Autoimmune Glomerulonephritis and in Antibody-Mediated Graft Rejection

Historically, oxidants have been considered mechanisms of glomerulonephritis, but a direct cause-effect correlation has never been demonstrated. Several findings in the experimental model of autoimmune conditions with renal manifestations point to the up-regulation of an oxidant/anti-oxidant system after the initial deposition of autoantibodies in glomeruli. Traces of oxidants in glomeruli cannot be directly measured for their rapid metabolism, while indirect proof of their implications is derived from the observation that Superoxide Oxidase 2 (SOD2) is generated by podocytes after autoimmune stress. The up-regulation of other anti-oxidant systems takes place as well. Here, we discuss the concept that a second wave of antibodies targeting SOD2 is generated in autoimmune glomerulonephritis and may negatively influence the clinical outcome. Circulating and renal deposits of anti-SOD2 antibodies have been detected in patients with membranous nephropathy and lupus nephritis, two main examples of autoimmune disease of the kidney, which correlate with the clinical outcome. The presence of anti-SOD2 antibodies in circulation and in the kidney has been interpreted as a mechanism which modifies the normal tissue response to oxidative stress. Overall, these findings repropose the role of the oxidant/anti-oxidant balance in autoimmune glomerulonephritis. The same conclusion on the oxidant/anti-oxidant balance may be proposed in renal transplant. Patients receiving a renal graft may develop antibodies specific for Glutathione Synthetase (GST), which modulates the amount of GST disposable for rapid scavenging of reactive oxygen species (ROS). The presence of anti-GST antibodies in serum is a major cause of rejection. The perspective is to utilize molecules with known anti-oxidant effects to modulate the anti-oxidative response in autoimmune pathology of the kidney. A lot of molecules with known anti-oxidant effects can be utilized, many of which have already been proven effective in animal models of autoimmune glomerulonephritis. Many molecules with anti-oxidant activity are natural products; in some cases, they are constituents of diets. Owing to the simplicity of these drugs and the absence of important adverse effects, many anti-oxidants could be directly utilized in human beings.

An Activity-Based Sensing Approach to Multiplex Mapping of Labile Copper Pools by Stimulated Raman Scattering

Molecular imaging with analyte-responsive probes offers a powerful chemical approach to studying biological processes. Many reagents for bioimaging employ a fluorescence readout, but the relatively broad emission bands of this modality and the need to alter the chemical structure of the fluorophore for different signal colors can potentially limit multiplex imaging. Here, we report a generalizable approach to multiplex analyte imaging by leveraging the comparably narrow spectral signatures of stimulated Raman scattering (SRS) in activity-based sensing (ABS) mode. We illustrate this concept with two copper Raman probes (CRPs), CRP2181 and CRP2153.2, that react selectively with loosely bound Cu(I/II) and Cu(II) ions, respectively, termed the labile copper pool, through copper-directed acyl imidazole (CDAI) chemistry. These reagents label proximal proteins in a copper-dependent manner using a dye scaffold bearing a 13C≡N or 13C≡15N isotopic SRS tag with nearly identical physiochemical properties in terms of shape and size. SRS imaging with the CRP reagents enables duplex monitoring of changes in intracellular labile Cu(I) and Cu(II) pools upon exogenous copper supplementation or copper depletion or genetic perturbations to copper transport proteins. Moreover, CRP imaging reveals reciprocal increases in labile Cu(II) pools upon decreases in activity of the antioxidant response nuclear factor-erythroid 2-related factor 2 (NRF2) in cellular models of lung adenocarcinoma. By showcasing the use of narrow-bandwidth ABS probes for multiplex imaging of copper pools in different oxidation states and identifying alterations in labile metal nutrient pools in cancer, this work establishes a foundation for broader SRS applications in analyte-responsive imaging in biological systems.

Bimodal accurate H2O2 regulation to equalize tumor-associated macrophage repolarization and immunogenic tumor cell death elicitation

Simultaneous implementation of tumor-associated macrophage (TAM) repolarization and immunogenic tumor cell death (ICD) elicitation enables tumor immunotherapy with high efficacy. However, the inconsistency of stimulation tolerance restricts simultaneous implementation. To address this obstacle, we validate that an H2O2-mediated regulatory strategy could achieve coordinated occurrences. To accomplish this, a bimodal responsive modulator is constructed, namely ZnO2-ATM (ATM: 3-amino-1,2,4-triazole), as an immune adjuvant to coordinate the occurrence of TAM repolarization and ICD elicitation through the endo/exogenous synergistic responsive production of H2O2. H2O2 produced by ZnO2-ATM reverses the immune-suppressive TAM from an M2 to an M1 phenotype, but induces tumor cell necrosis and promotes damage-related molecular pattern release, thereby evoking ICD. This H2O2-mediation bimodal responsive therapeutic strategy to induce the synergistic occurrence of TAM repolarization and ICD elicitation promotes effective immune effects against tumors, demonstrating that the ZnO2-ATM nanoadjuvant could be expected to provide new tools and paradigms for antitumor immunotherapy.

A manganese-oxide nano-rambutan as the intrinsic modifier for hypericin delivery and triple-negative breast cancer treatment

The anti-tumor efficacy of naturally derived photosensitizer-hypericin (Hy) is dampened by hypoxia and over-expressed glutathione in the tumor microenvironment (TME). For rewiring the TME, we encapsulated Hy to an intrinsic modifier-manganese oxide-formed nanorambutan (MnOx-Hy NR). In triple-negative breast cancer cells, MnOx-Hy NR not only consumed glutathione through Mn2+ and hypericin release but also facilitated O2 production to relieve hypoxia, through which the reactive oxygen species (ROS) generation was strengthened by endoplasmic reticulum targeting hypericin. In the meantime, glutathione consumption-induced glutathione peroxidase 4 (GPX4) inactivation and the elevation of lipid hydroperoxide (LPO) level further triggered ferroptosis. Then, the combination of PDT and ferroptosis contributed to a synergic immunogenic cell death (ICD) effect in 4 T1 cells, facilitating the adaptive anti-tumor immune response activation. Thereby, MnOx-Hy NR exhibited excellent anti-tumor effects both in primary and distant tumors through the abscopal effect, as well as significant lung metastasis inhibition in the 4 T1 mouse metastatic tumor model.

Engineered Reactive Oxygen Species (ROS)-Responsive Artificial H+/Cl- Ion Channels for Targeted Cancer Treatment

Reactive oxygen species (ROS)-responsive ion channels regulate the ion flow across the membranes in response to alterations in the cellular redox state, playing a crucial role in cellular adaptation to oxidative stress. Despite their significance, replicating ROS-responsive functionality in artificial ion channels remains elusive. In this study, we introduce a novel class of artificial H+/Cl- ion channels activatable by elevated ROS levels in cancer cells. ROS-induced decaging of the phenylboronate group triggers the rapid release of the channel-forming units, leading to self-assembly of the H-bonded cascades facilitating the synergistic transport of H+ and Cl- ions, with H+/Cl- ion transport selectivity of 7.7. Upon activation, ROS-C-Cl exhibits significant apoptotic activity against human breast cancer cells, achieving an IC50 of 2.8 μM, comparable to that of paclitaxel. Exploiting the intrinsic oxidative microenvironment of cancer cells, along with the enhanced oxidative stress arising from H+/Cl- co-transport, ROS-C-Cl demonstrates exceptional selectivity in targeting cancer cells with a selectivity index of 10.2 over normal breast cells, outperforming that of paclitaxel by 19.4 folds.

Benzo (A) pyrene exposure alters alveolar epithelial and macrophage cells diversity and induces antioxidant responses in lungs

This study was designed to investigate the toxic effects of benzo (a) pyrene (BaP) in the lungs. Mice were repeatedly treated orally with BaP (50 mg/kg body weight, twice a week for four weeks) to induce a tumour. After 4 months of BaP administration, tumours were visible beneath the skin. The histopathological section of the lungs shows congestion of pulmonary blood vessels, alveolar hyperplasia, and concurrent epithelial hyperplasia with infiltrates of inflammatory cells also seen. Thereafter, a single-cell suspension of lung tissues was stained with fluorescently conjugated antibodies for the demarcation of alveolar epithelial (anti-mouse CD74 and podoplanin) and macrophage (F4/80 and CD11b) cells and measured by flow cytometry. The expression of antioxidant genes was assessed by qRT-PCR. The number of alveolar epithelial cells 1 (AEC1) increased, but the number of alveolar epithelial cells 2 (AEC2) and transitional alveolar epithelial cells (TAEC) was significantly decreased in tumour-bearing mice. The proportion of CD11b+ alveolar macrophages (AM) and interstitial macrophages (IM) was increased, but the proportion of F4/80+ AM cells was reduced. The BaP administration significantly increased the ROS production in alveolar cells. The relative expression levels of antioxidant genes (SOD1, catalase, GPX1, and HIF-1α) were increased, but NRF2 expression was decreased in BaP-treated alveolar cells. The expression of anti-inflammatory (NF-κB) was also significantly increased. In conclusion, BaP exposure induced an inflammatory response, altered alveolar epithelial cell and macrophage diversity, and increased antioxidant responses in the lungs.

Hydroxyethyl starch-based self-reinforced nanomedicine inhibits both glutathione and thioredoxin antioxidant pathways to boost reactive oxygen species-powered immunotherapy

The adaptive antioxidant systems of tumor cells, predominantly glutathione (GSH) and thioredoxin (TRX) networks, severely impair photodynamic therapy (PDT) potency and anti-tumor immune responses. Here, a multistage redox homeostasis nanodisruptor (Phy@HES-IR), integrated by hydroxyethyl starch (HES)-new indocyanine green (IR820) conjugates with physcion (Phy), an inhibitor of the pentose phosphate pathway (PPP), is rationally designed to achieve PDT primed cancer immunotherapy. In this nanodisruptor, Phy effectively depletes intracellular GSH of tumor cells by inhibiting 6-phosphogluconate dehydrogenase (6PGD) activity. Concurrently, it is observed for the first time that the modified IR820-NH2 molecule not only exerts PDT action but also interferes with TRX antioxidant pathway by inhibiting thioredoxin oxidase (TRXR) activity. The simultaneous weakening of two major antioxidant pathways of tumor cells is favorable to maximize the PDT efficacy induced by HES-IR conjugates. By virtue of the excellent protecting ability of the plasma expander HES, Phy@HES-IR can remain stable in the blood circulation and efficiently enrich in the tumor region. Consequently, PDT and metabolic modulation synergistically induced immunogenic cell death, which not only suppressed primary tumors but also stimulated potent anti-tumor immunity to inhibit the growth of distant tumors in 4T1 tumor-bearing mice.

Procyanidin B1 Promotes PSMC3-NRF2 Ubiquitination to Induce Ferroptosis in Glioblastoma

NRF2 signaling is a crucial antioxidant defense mechanism against ferroptosis in tumors, and targeting NRF2 is essential for tumor therapy. However, the effectiveness of NRF2 inhibitors remains unexplored. The active ingredients of traditional Chinese medicine serve as important sources of NRF2 inhibitors. In this study, we established an intracranial glioblastoma (GBM) orthotopic model and observed the effects of procyanidin B1 on tumor growth and ferroptosis. Using protein-small-molecule docking, z-stack assay of laser confocal imaging, surface plasmon resonance assay, immunoprecipitation, mass spectrometry, and western blotting, we detected the binding between procyanidin B1 and NRF2 and the effect of PSMC3 on the ubiquitin-dependent degradation of NRF2 in GBM cells. Our results showed that procyanidin B1 acted as a novel NRF2 inhibitor to suppress GBM cell proliferation and prolonged the survival of GBM-bearing mice; it also mediated the interaction between PSMC3 and NRF2 to promote ubiquitin-dependent protein degradation of NRF2, which induced ferroptosis in GBM cells. In addition, we found that procyanidin B1 enhanced H₂O₂ accumulation by downregulating NRF2 during ferroptosis in GBM cells. The botanical agent procyanidin B1 induced ferroptosis and exerted anti-tumor effects through PSMC3-mediated ubiquitin-dependent degradation of NRF2 proteins, providing a potential drug candidate for adjuvant therapy in patients with GBM.

MTHFD2-mediated redox homeostasis promotes gastric cancer progression under hypoxic conditions

OBJECTIVES

Cancer cells undergo metabolic reprogramming to adapt to high oxidative stress, but little is known about how metabolic remodeling enables gastric cancer cells to survive stress associated with aberrant reactive oxygen species (ROS) production. Here, we aimed to identify the key metabolic enzymes that protect gastric cancer (GC) cells from oxidative stress.

METHODS

ROS level was detected by DCFH-DA probes. Multiple cell biological studies were performed to identify the underlying mechanisms. Furthermore, cell-based xenograft and patient-derived xenograft (PDX) model were performed to evaluate the role of MTHFD2 in vivo.

RESULTS

We found that overexpression of MTHFD2, but not MTHFD1, is associated with reduced overall and disease-free survival in gastric cancer. In addition, MTHFD2 knockdown reduces the cellular NADPH/NADP+ ratio, colony formation and mitochondrial function, increases cellular ROS and cleaved PARP levels and induces in cell death under hypoxia, a hallmark of solid cancers and a common inducer of oxidative stress. Moreover, genetic or pharmacological inhibition of MTHFD2 reduces tumor burden in both tumor cell lines and patient-derived xenograft-based models.

DISCUSSION

our study highlights the crucial role of MTHFD2 in redox regulation and tumor progression, demonstrating the therapeutic potential of targeting MTHFD2.

Tumor energy metabolism: implications for therapeutic targets

Tumor energy metabolism plays a crucial role in the occurrence, progression, and drug resistance of tumors. The study of tumor energy metabolism has gradually become an emerging field of tumor treatment. Recent studies have shown that epigenetic regulation is closely linked to tumor energy metabolism, influencing the metabolic remodeling and biological traits of tumor cells. This review focuses on the primary pathways of tumor energy metabolism and explores therapeutic strategies to target these pathways. It covers key areas such as glycolysis, the Warburg effect, mitochondrial function, oxidative phosphorylation, and the metabolic adaptability of tumors. Additionally, this article examines the role of the epigenetic regulator SWI/SNF complex in tumor metabolism, specifically its interactions with glucose, lipids, and amino acids. Summarizing therapeutic strategies aimed at these metabolic pathways, including inhibitors of glycolysis, mitochondrial-targeted drugs, exploitation of metabolic vulnerabilities, and recent developments related to SWI/SNF complexes as potential targets. The clinical significance, challenges, and future directions of tumor metabolism research are discussed, including strategies to overcome drug resistance, the potential of combination therapy, and the application of new technologies.

The Molecular Characterization and Antioxidant Defense of a Novel Nrf2 from the Pacific Abalone Haliotis discus hannai Ino

The Nrf2/ARE pathway is considered the most important endogenous antioxidant signaling pathway in mammals, playing a crucial role in defending against external damage. This study investigated the functional characteristics of Nrf2 in the abalone, Haliotis discus hannai. The full-length cDNA sequence of the HdhNrf2 gene was cloned using rapid amplification of cDNA ends (RACE) technology and consists of 4568 base pairs encoding a protein of 694 amino acids. The predicted theoretical molecular weight was 77 kDa, with an isoelectric point of 4.72. Multiple sequence alignment analysis revealed the relative conservation of the HdhNrf2 amino acid sequence in H. discus hannai. The tissue expression pattern of the HdhNrf2 gene was analyzed using real-time fluorescence quantitative PCR, which showed the highest expression in the gills, followed by hemocytes, with the lowest levels in the foot and mantle. The inducible expression of HdhNrf2 and antioxidant genes in abalone under H2O2 stress was investigated at various time points. Furthermore, an expression vector, pET-28a(+)-rHdhNrf2, was constructed, and the recombinant protein rHdhNrf2 was obtained through induced expression and purification. These findings indicated that HdhNrf2 plays a crucial role in the defense of abalones against oxidative stress.

Recent progress in organelle-targeting fluorescent probes for the detection of peroxynitrite

Peroxynitrite (ONOO-), as an important reactive nitrogen species, plays a pivotal role in the regulation of intracellular redox homeostasis, signal transduction, cell growth and metabolism, and other physiological processes. Organelles are important for regulating ONOO-, and the dysregulation of ONOO- in organelles is closely related to various diseases. Therefore, it is essential to monitor ONOO- in cellular organelles, including mitochondria, lysosome, endoplasmic reticulum (ER), Golgi apparatus, and lipid droplets. However, the latest advances in organelle-targeting ONOO- fluorescent probes have not been reviewed systematically. In this review, we focus on the design, sensing mechanism, and organelle-targeting imaging applications of ONOO- fluorescent probes that were reported since 2018. This review will help to facilitate the comprehension of organelle-targeting fluorescent probes for the detection of ONOO-.

Evaluation of Anticancer and Immunomodulatory Effects of Microwave-Extracted Polysaccharide from Ruditapes philippinarum

In recent years, research on active polysaccharides has progressed significantly, particularly regarding their anticancer and immunomodulatory properties. Among these, clam polysaccharides, a type of marine-derived polysaccharide, exhibit notable biological activities, including both anticancer effects and immune modulation. The aims of this study are to investigate the anticancer and immunomodulatory effects of microwave-extracted clam polysaccharide (MCP) in vitro. Cell experiments demonstrated that MCP significantly inhibited both colony formation and migration of HT-29 cells. Furthermore, treatment with MCP led to the downregulation of Bcl-2 gene expression, a reduction in mitochondrial membrane potential, activation of cytochrome C gene and caspase-3 gene, and, finally, the induction of apoptosis in HT-29 cells, implying the involvement of the mitochondrial pathway. Additionally, MCP was found to prompt a phenotypic shift in macrophages from M2 to M1 subtype and from M0 to M1 subtype. MCP also decreased reactive oxygen species (ROS) levels within the cancer cells, thereby augmenting anticancer efficacy through a dual mechanism of immune activation and antioxidant enhancement. These findings suggest that MCPs present significant potential as natural antitumor agents and immunomodulators, especially in the development of functional foods or drugs.

New Emerging Therapeutic Strategies Based on Manipulation of the Redox Regulation Against Therapy Resistance in Cancer

Background: Resistance to standard therapeutic methods, including chemotherapy, immunotherapy, and targeted therapy, remains a critical challenge in effective cancer treatment. Redox homeostasis modification has emerged as a promising approach to address medication resistance. Objective: This review aims to explore the mechanisms of redox alterations and signaling pathways contributing to treatment resistance in cancer. Methods: In this study, a comprehensive review of the molecular mechanisms underlying drug resistance governed by redox signaling was conducted. Emphasis was placed on understanding how tumor cells manage increased reactive oxygen species (ROS) levels through upregulated antioxidant systems, enabling resistance across multiple therapeutic pathways. Results: Key mechanisms identified include alterations in drug efflux, target modifications, metabolic changes, enhanced DNA damage repair, stemness preservation, and tumor microenvironment remodeling. These pathways collectively facilitate tumor cells' adaptive response and resistance to various cancer treatments. Conclusion: Developing a detailed understanding of the interrelationships between these redox-regulated mechanisms and therapeutic resistance holds potential to improve treatment effectiveness, offering valuable insights for both fundamental and clinical cancer research. Antioxid. Redox Signal. 00, 000-000.

Development of a hybrid rhodamine-hydrazine NIR fluorescent probe for sensitive detection and imaging of peroxynitrite in necrotizing enterocolitis model

This study describes the synthesis and characterization of a novel near-infrared (NIR) fluorescent probe RBNE based on a hybrid rhodamine dye, which shows excellent optical capability for detecting and imaging ONOO- in necrotizing enterocolitis (NEC) mouse model. The probe RBNE undergoes hydrazine redox-process, and subsequently the spirocyclic structure's opening, resulting in a turn-on fluorescence emission with the presence of ONOO-, which exhibits several excellent features, including a significant Stokes shift of 108 nm, near-infrared emission at 668 nm, a lower detection limit of 56 nM, low cytotoxicity, and excellent imaging ability for ONOO- both in vitro and in vivo. The presented study introduces a novel optical tool that has the potential to significantly advance our understanding of peroxynitrite (ONOO-) behaviors in necrotizing enterocolitis (NEC).

Bottle Nanomotors Amplify Tumor Oxidative Stress for Enhanced Calcium Overload/Chemodynamic Therapy

Developing multifunctional, stimuli-responsive nanomedicine is intriguing because it has the potential to effectively treat cancer. Yet, poor tumor penetration of nanodrugs results in limited antitumor efficacy. Herein, an oxygen-driven silicon-based nanomotor (Si-motor) loaded with MnO and CaO2 nanoparticles is developed, which can move in tumor microenvironment (TME) by the cascade reaction of CaO2 and MnO. Under acidic TME, CaO2 reacts with acid to release Ca2+ to induce mitochondrial damage and simultaneously produces O2 and H2O2, when the loaded MnO exerts Fenton-like activity to produce ·OH and O2 based on the produced H2O2. The generated O2 drives Si-motor forward, thus endowing active delivery capability of the formed motors in TME. Meanwhile, MnO with glutathione (GSH) depletion ability further prevents reactive oxygen species (ROS) from being destroyed. Such TME actuated Si-motor with enhanced cellular uptake and deep penetration provides amplification of synergistic oxidative stresscaused by intracellular Ca2 + overloading, GSH depletion induced by Mn2+, and Mn2+ mediated chemodynamic treatment (CDT), leading to excellent tumor cell death. The created nanomotor may offer an effective platform for active synergistic cancer treatment.

Inhibition of KDM4A restricts SQLE transcription and induces oxidative stress imbalance to suppress bladder cancer

In clinical practice, the limited efficacy of standard comprehensive therapy for advanced bladder cancer and the lack of targeted treatment options are well recognized. Targeting abnormal epigenetic modifications in tumors has shown considerable potential in cancer therapy. Through drug screening in tumor organoids, we identified that ML324, a histone lysine demethylase 4A (KDM4A) inhibitor, exhibits potent antitumor effects in both in vitro and in vivo cancer models. Mechanistically, Kdm4a demethylates H3K9me3, leading to chromatin opening and increased accessibility of Gabpa to the squalene epoxidase (Sqle) gene promoter, resulting in transcriptional activation. Inhibition of Kdm4a downregulates Sqle transcription, blocking cholesterol synthesis and causing squalene (SQA) accumulation. This process induces reactive oxygen species (ROS) clearance and suppresses JNK/c-Jun phosphorylation, ultimately inducing apoptosis. Furthermore, ML324 treatment significantly inhibited tumor growth in bladder cancer patient-derived xenograft (PDX) models. Our findings reveal the presence of a Kdm4a-Sqle-ROS-JNK/c-Jun signaling axis that regulates oxidative stress balance, offering a novel strategy for targeted therapy in bladder cancer.

Role of MTH1 in oxidative stress and therapeutic targeting of cancer

Cancer cells maintain high levels of reactive oxygen species (ROS) to drive their growth, but ROS can trigger cell death through oxidative stress and DNA damage. To survive enhanced ROS levels, cancer cells activate their antioxidant defenses. One such defense is MTH1, an enzyme that prevents the incorporation of oxidized nucleotides into DNA, thus preventing DNA damage and allowing cancer to proliferate. MTH1 levels are often elevated in many cancers, and thus, inhibiting MTH1 is an attractive strategy for suppressing tumor growth and metastasis. Targeted MTH1 inhibition can induce DNA damage in cancer cells, exploiting their vulnerability to oxidative stress and selectively targeting them for destruction. Targeting MTH1 is promising for cancer treatment because normal cells have lower ROS levels and are less dependent on these pathways, making the approach both effective and specific to cancer. This review aims to investigate the potential of MTH1 as a therapeutic target, especially in cancer treatment, offering detailed insights into its structure, function, and role in disease progression. We also discussed various MTH1 inhibitors that have been developed to selectively induce oxidative damage in cancer cells, though their effectiveness varies. In addition, this review provide deeper mechanistic insights into the role of MTH1 in cancer prevention and oxidative stress management in various diseases.

The Complex Roles of Redox and Antioxidant Biology in Cancer

Redox reactions control fundamental biochemical processes, including energy production, metabolism, respiration, detoxification, and signal transduction. Cancer cells, due to their generally active metabolism for sustained proliferation, produce high levels of reactive oxygen species (ROS) compared to normal cells and are equipped with antioxidant defense systems to counteract the detrimental effects of ROS to maintain redox homeostasis. The KEAP1-NRF2 system plays a major role in sensing and regulating endogenous antioxidant defenses in both normal and cancer cells, creating a bivalent contribution of NRF2 to cancer prevention and therapy. Cancer cells hijack the NRF2-dependent antioxidant program and exploit a very unique metabolism as a trade-off for enhanced antioxidant capacity. This work provides an overview of redox metabolism in cancer cells, highlighting the role of the KEAP1-NRF2 system, selenoproteins, sulfur metabolism, heme/iron metabolism, and antioxidants. Finally, we describe therapeutic approaches that can be leveraged to target redox metabolism in cancer.

SPAG6 overexpression decreases the pro-apoptotic effect of daunorubicin in acute myeloid leukemia cells through the ROS/JNK MAPK axis in a GSTP1-dependent manner

Introduction

As a malignant hematological disease, the incidence of acute myeloid leukemia (AML) has exhibited an upward trend in recent years. Nevertheless, certain limitations persist in the treatment of AML. Sperm-associated antigen 6 (SPAG6) has been implicated in the onset and progression of various human cancers, with its expression levels significantly elevated in AML. Consequently, we undertook a series of experiments to investigate the role and underlying mechanisms of SPAG6 in AML cell lines.

Methods

In the in vitro experiments of this study, DEPs and GO and KEGG enrichment analysis subsequent to SPAG6 down-regulation were detected by TMT. CCK8 was employed to determine cell viability. The levels of apoptosis and ROS were measured by flow cytometry. In the in vivo experiments, a xenografted tumor model was constructed, and the expression of SPAG6 and GSTP1 in tumor tissues was detected by IHC.

Results

Ultimately, our findings indicated that over-expression of SPAG6 promoted cell growth and decreased reactive oxygen species (ROS) and malondialdehyde levels. Furthermore, SPAG6 knockdown was found to diminish mitochondrial membrane potential and facilitate cell apoptosis. In vivo, SPAG6 could also promote tumor growth, suggesting that SPAG6 may serve as a pro-tumor factor. In addition, daunorubicin (DNR) may cause oxidative stress and initiate apoptosis, resulting in oxidative damage to AML cells. However, the overexpression of SPAG6 may attenuate the efficacy of DNR. This was due to SPAG6 promoted GSTP1 expression, thereby reducing ROS levels. Simultaneously, the elevation of GSTP1 and JNK complex may reduce the expression of p-JNK and inhibit the activation of JNK pathway, which might inhibit cell apoptosis.

Discussion

In conclusion, our experiments suggested that upregulated SPAG6 might mitigate the pro-apoptotic effects of DNR through ROS/JNK MAPK axis in a GSTP1-dependent manner.

Nrf2/Keap1/ARE regulation by plant secondary metabolites: a new horizon in brain tumor management

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same.

Growth Signaling Networks Orchestrate Cancer Metabolic Networks

Normal cells grow and divide only when instructed to by signaling pathways stimulated by exogenous growth factors. A nearly ubiquitous feature of cancer cells is their capacity to grow independent of such signals, in an uncontrolled, cell-intrinsic manner. This property arises due to the frequent oncogenic activation of core growth factor signaling pathway components, including receptor tyrosine kinases, PI3K-AKT, RAS-RAF, mTORC1, and MYC, leading to the aberrant propagation of pro-growth signals independent of exogenous growth factors. The growth of both normal and cancer cells requires the acquisition of nutrients and their anabolic conversion to the primary macromolecules underlying biomass production (protein, nucleic acids, and lipids). The core growth factor signaling pathways exert tight regulation of these metabolic processes and the oncogenic activation of these pathways drive the key metabolic properties of cancer cells and tumors. Here, we review the molecular mechanisms through which these growth signaling pathways control and coordinate cancer metabolism.

A GSH-Responsive Prodrug with Simultaneous Triple-Activation Capacity for Photodynamic/Sonodynamic Combination Therapy with Inhibited Skin Phototoxicity

Herein, a dual-sensitizer prodrug, named pro-THPC, has been designed to function as both a photosensitizer and a sonosensitizer prodrug for precise antitumor combination therapy with minimized skin phototoxicity. Pro-THPC could be activated by glutathione (GSH) to release the dual-sensitizer, THPC, which simultaneously switches on fluorescence emission and combined capabilities of photodynamic therapy (PDT) and sonodynamic therapy (SDT). Pro-THPC is further formulated into nanoparticles (NPs) for water dispersity to enable in vivo applications. In vivo fluorescence imaging shows that the pro-THPC NPs group exhibits a significantly higher tumor-to-normal tissue ratio (T/N) (T/N = 5.2 ± 0.55) compared to the "always on" THPC NPs group (T/N = 2.9 ± 0.47) and the pro-THPC NPs group co-administrated with GSH synthesis inhibitor (buthionine sulfoximine, BSO) (T/N = 3.2 ± 0.63). In addition, the generation of the designed dual-sensitizer's reactive oxygen species (ROS) is effectively confined within the tumor tissues due to the relatively strong correlation between ROS generation and fluorescence emission. In vivo studies further demonstrate the remarkable efficacy of the designed pro-THPC NPs to eradicate tumors through the combination of PDT and SDT while significantly reducing skin phototoxicity.

Targeting PAX8 sensitizes ovarian cancer cells to ferroptosis by inhibiting glutathione synthesis

Ovarian cancer is a malignant tumor originating from the ovary, characterized by its high mortality rate and propensity for recurrence. In some patients, especially those with recurrent cancer, conventional treatments such as surgical resection or standard chemotherapy yield suboptimal results. Consequently, there is an urgent need for novel anti-cancer therapeutic strategies. Ferroptosis is a distinct form of cell death separate from apoptosis. Ferroptosis inducers have demonstrated promising potential in the treatment of ovarian cancer, with evidence indicating their ability to enhance ovarian cancer cell sensitivity to cisplatin. However, resistance of cancer cells to ferroptosis still remains an inevitable challenge. Here, we analyzed genome-scale CRISPR-Cas9 loss-of function screens and identified PAX8 as a ferroptosis resistance protein in ovarian cancer. We identified PAX8 as a susceptibility gene in GPX4-dependent ovarian cancer. Depletion of PAX8 rendered GPX4-dependent ovarian cancer cells significantly more sensitive to GPX4 inhibitors. Additionally, we found that PAX8 inhibited ferroptosis in ovarian cancer cells. Combined treatment with a PAX8 inhibitor and RSL3 suppressed ovarian cancer cell growth, induced ferroptosis, and was validated in a xenograft mouse model. Further exploration of the molecular mechanisms underlying PAX8 inhibition of ferroptosis mutations revealed upregulation of glutamate-cysteine ligase catalytic subunit (GCLC) expression. GCLC mediated the ferroptosis resistance induced by PAX8 in ovarian cancer. In conclusion, our study underscores the pivotal role of PAX8 as a therapeutic target in GPX4-dependent ovarian cancer. The combination of PAX8 inhibitors such as losartan and captopril with ferroptosis inducers represents a promising new approach for ovarian cancer therapy.

An "AND" logic gate-based supramolecular therapeutic nanoplatform for combatting drug-resistant non-small cell lung cancer

Despite targeted therapies like epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), non-small cell lung cancer (NSCLC) remains a clinical challenge due to drug resistance hampering their efficacy. Here, we designed an "AND" logic gate-based supramolecular therapeutic platform (HA-BPY-GEF-NPs) for the treatment of EGFR-TKI resistant NSCLC. This system integrates both internal and external stimuli-responsive mechanisms that need to be activated in a preset sequence, enabling it to precisely control drug release behavior for enhancing therapeutic precision. By programming the system to respond to sequential near-infrared (NIR) irradiation and enzyme (cathepsin B) inputs, the release of gefitinib is effectively confined to the tumor region. Moreover, the NIR irradiation induces reactive oxygen species production, suppressing tumor growth and inhibiting bypass signaling pathways. The designed drug delivery system offers a highly controlled and targeted therapeutic approach, effectively inhibiting tumor growth, suppressing bypass signaling pathways, and overcoming EGFR-TKI resistance, thus offering a potential solution for maximizing therapeutic benefits.

Beyond genetics: integrative oncology and the metabolic perspective on cancer treatment

Cancer is traditionally approached as a genetic disease, with standard treatments including chemotherapy, radiation, targeted therapy, immunotherapy, and surgery significantly improving survival rates and patient outcomes. However, there is a growing recognition of the need for integrative oncology, which expands cancer management by considering cancer as a metabolic disease. Integrative medicine physicians employ holistic therapies focused on patients' needs, aiming to correct the metabolic imbalances associated with cancer and alleviate cancer-related symptoms. Viewing cancer as a metabolic disease involves addressing factors such as an acidic microenvironment, vitamin C deficiency, mitochondrial dysfunction, reduced intracellular oxygen levels, elevated oxidative stress, dysfunctional autophagy, and psychological stress. This paper presents an overview of the evidence and comprehensive strategies supporting integrative medicine approaches in addressing cancer metabolism in integrative oncology settings. Furthermore, the paper underscores the necessity of integrating different cancer theories-genetic and metabolic-for improved patient outcomes and experiences. By combining these perspectives, integrative oncology offers a more holistic, patient-centered approach to cancer treatment.

The role of polydatin in inhibiting oxidative stress through SIRT1 activation: A comprehensive review of molecular targets

ETHNOPHARMACOLOGICAL RELEVANCE

Reynoutria japonica Houtt is a medicinal plant renowned for its diverse pharmacological properties, including heat-clearing, toxin-removing, blood circulation promotion, blood stasis removal, diuretic action, and pain relief. The plant is commonly utilized in Traditional Chinese Medicine (TCM), and its major bioactive constituents consist of polydatin (PD) and resveratrol (RES).

AIM OF THE STUDY

To summarize the relevant targets of PD in various oxidative stress-related diseases through the activation of Silence information regulator1 (SIRT1). Furthermore, elucidating the pharmacological effects and signaling mechanisms to establish the basis for PD's secure clinical implementation and expanded range of application.

MATERIALS AND METHODS

Literature published before November 2023 on the structural analysis and pharmacological activities of PD was collected using online databases such as Google Scholar, PubMed, and Web of Science. The keywords were "polydatin", "SIRT1" and "oxidative stress". The inclusion criteria were research articles published in English, including in vivo and in vitro experiments and clinical studies. Non-research articles such as reviews, meta-analyses, and letters were excluded.

RESULTS

PD has been found to have significantly protective and curative effects on diseases associated with oxidative stress by regulating SIRT1-related targets including peroxisome proliferator-activated receptor γ coactivator 1-alpha (PGC-1α), nuclear factor erythroid2-related factor 2 (Nrf2), high mobility group box 1 protein (HMGB1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), p38/p53, as well as endothelial nitric oxide synthase (eNOs), among others. Strong evidence suggests that PD is an effective natural product for treating diseases related to oxidative stress.

CONCLUSION

PD holds promise as an effective treatment for a wide range of diseases, with SIRT1-mediated oxidative stress as its potential pathway.

Theoretical insights into a turn-on fluorescence probe based on naphthalimide for peroxynitrite detection

Compared with other reactive oxygen species, peroxynitrite (ONOO-) has diversified reactions and transformations in organisms, and its specific action mechanism is not very clear. The study of reactive oxygen species is of great significance in the field of physiology and pathology. Recently an effective on/off fluorescent probe HCA-OH was designed by Liu et al. through tethering p-aminophenol to 1,8-naphthalimide directly. The probe HCA-OH could release the fluorophore HCA-NH2 with good photostability and high fluorescence quantum yield under oxidation of ONOO- via dearylation process. In this work, the sensing mechanism and spectrum character of probe HCA-OH were studied in detail under quantum chemistry calculation. The electronic structures, reaction sites and fluorescent properties of the probe were theoretically analyzed to benefit us for in-depth understanding the principle of detection on reactive oxygen species (ONOO-) with the fluorescent probe HCA-OH. These theoretical results could inspire the medical research community to design and synthesize highly efficient fluorescent probe for reactive oxygen species detection.

Digitonin-Loaded Nanoscale Metal-Organic Framework for Mitochondria-Targeted Radiotherapy-Radiodynamic Therapy and Disulfidptosis

The efficacy of radiotherapy (RT) is limited by inefficient X-ray absorption and reactive oxygen species generation, upregulation of immunosuppressive factors, and a reducing tumor microenvironment (TME). Here, the design of a mitochondria-targeted and digitonin (Dig)-loaded nanoscale metal-organic framework, Th-Ir-DBB/Dig, is reported to overcome these limitations and elicit strong antitumor effects upon low-dose X-ray irradiation. Built from Th6O4(OH)4 secondary building units (SBUs) and photosensitizing Ir(DBB)(ppy)2 2+ (Ir-DBB, DBB = 4,4'-di(4-benzoato)-2,2'-bipyridine; ppy = 2-phenylpyridine) ligands, Th-Ir-DBB exhibits strong RT-radiodynamic therapy (RDT) effects via potent radiosensitization with high-Z SBUs for hydroxyl radical generation and efficient excitation of Ir-DBB ligands for singlet oxygen production. Th-Ir-DBB/Dig releases digitonin in acidic TMEs to trigger disulfidptosis of cancer cells and sensitize cancer cells to RT-RDT through glucose and glutathione depletion. The released digitonin simultaneously downregulates multiple immune checkpoints in cancer cells and T cells through cholesterol depletion. As a result, Th-Ir-DBB/dig plus X-ray irradiation induces strong antitumor immunity to effectively inhibit tumor growth in mouse models of colon and breast cancer.

Dual-stimuli responsive theranostic agents based on small molecules

Stimuli-responsive theranostic agents represent a class of molecules that integrate therapeutic and diagnostic functions, offering the capability to respond to disease-associated biomarkers. Dual-stimuli responsive agents, particularly those based on small molecules, have shown considerable promise for precise imaging-guided therapeutic applications. In this Highlight, we summarize the progress of dual-stimuli responsive theranostic agents based on small molecules, for diagnostic and therapeutic studies in biological systems. The Highlight focuses on comparing different responsive groups and chemical structures of these dual-stimuli responsive theranostic agents towards different biomarkers. The potential future directions of the agents for further applications in biological systems are also discussed.

Structural characterisation of a novel polysaccharide from pseudostellaria heterophylla fibrous root and its anti-inflammatory and antioxidant activities in vitro

A novel water-soluble polysaccharide, named PF90-1, with a molecular weight of 1.8 kDa, was isolated and purified from the fibrous root of Pseudostellaria heterophylla. PF90-1 is composed of Gal, Glc and Man in a molar ratio of 73.61: 19.11: 7.28. Methylation analysis revealed that PF90-1 comprises of T-Galp, 1,4-Galp, 1,3,4-Galp, 1,2,3,4-Galp, T-Glcp and 1,3-Manp in a molar ratio of 37.89: 9.37: 17.01: 12.01: 15.88: 7.83. Bioactivity experiments showed that PF90-1 significantly improved lipopolysaccharide (LPS)-induced inflammatory damage in RAW264.7 cells by inhibiting nitric oxide (NO) production and reducing the levels of pro-inflammatory factors (IL-1β and TNF-α). In addition, PF90-1 exhibited strong antioxidant effects, protecting PC12 cells from H2O2-induced oxidative damage. This findings suggest that PF90-1 holds potential therapeutic value for the treatment of inflammatory and oxidative injuries.