👤 Yue Zheng

Glutathione (GSH), the most abundant intracellular thiol-containing antioxidant, plays a pivotal role in cellular metabolism and redox homeostasis. Its critical involvement in cancer and neurodegenerative diseases has made it an important target for thiol detection systems. In this work, we report the design and synthesis of two novel near-infrared (NIR) phosphorescent Ir(III) complexes as multifunctional probes for GSH detection and photodynamic therapy (PDT). These probes feature an α,β-unsaturated ketone moiety that selectively reacts with the thiol group in GSH, enabling the specific sensing of intracellular and extracellular GSH with applications in bioimaging. Beyond their sensing capabilities, both Ir(III) complexes exhibit strong reactive oxygen species (ROS) generation efficiency, aggregation-induced emission (AIE) characteristics, and mitochondria-targeting properties, making them highly effective for PDT. Notably, upon cellular uptake, these complexes deplete mitochondrial GSH, disrupting redox homeostasis and triggering a rapid accumulation of localized ROS. This dual mechanism─combining GSH depletion and enhanced ROS production─induces potent apoptotic cell death. This work provides a strategic approach for developing advanced NIR photosensitizers with AIE activity, mitochondria-specific targeting, and the ability to simultaneously engage type I and type II PDT pathways while modulating intracellular antioxidant defense systems. Such multifunctional theranostic probes offer considerable potential for enhancing the efficacy of photodynamic cancer therapy, particularly in the treatment of hypoxic tumors. Show less

The oxygen evolution reaction under neutral conditions remains a significant challenge due to sluggish kinetics and catalyst instability, largely stemming from inefficient proton management. Inspired by the proton-coupled electron transfer (PCET) networks in the oxygen-evolving complex of photosystem II, we report the rational design of two bioinspired cubane-type tetranuclear copper catalysts, Cu₄(L_Gly)₄ and Cu₄(L_Glu)₄, functionalized with amino acid derivatives. Electrochemical studies reveal that the glutamate-modified Cu₄(L_Glu)₄ outperforms its glycine counterpart, achieving a remarkable turnover frequency (TOF) of 9.64 ± 0.07 s^-1 at a low overpotential of 0.63 V in phosphate buffer solution (pH 7.30). Differential pulse voltammetry and mechanistic investigations indicate a PCET nature for the copper redox transitions. Density functional theory calculations demonstrate that the carboxylate group of the glutamate residue acts as an intrinsic proton relay, significantly lowering the energy barrier for the critical O-O bond formation step. Furthermore, a photovoltaic-electrocatalytic (PV-EC) device utilizing the Cu₄(L_Glu)₄ anode achieves a solar-to-hydrogen (STH) conversion efficiency of 10.24% under neutral conditions, one of the highest reported values without a strong alkaline environment. This work underscores the critical role of second-sphere proton-transfer functionality in designing efficient molecular catalysts for PCET-driven energy conversion reactions. Show less

N-acetyl-l-cysteine (NAC) is a medication and a widely used antioxidant in cell death research. Despite its somewhat obscure mechanism of action, its role in inhibiting ferroptosis is gaining increasing recognition. In this study, we demonstrate that NAC treatment rapidly replenishes the intracellular cysteine pool, reinforcing its function as a prodrug for cysteine. Interestingly, its enantiomer, N-acetyl-d-cysteine (d-NAC), which cannot be converted into cysteine, also exhibits a strong anti-ferroptotic effect. We further clarify that NAC, d-NAC, and cysteine all act as direct reducing substrates for GPX4, counteracting lipid peroxidation. Consequently, only GPX4-rather than system xc-, glutathione biosynthesis, or ferroptosis suppressor protein 1-is necessary for NAC and d-NAC to prevent ferroptosis. Additionally, we identify a broad range of reducing substrates for GPX4 in vitro, including β-mercaptoethanol. These findings provide new insights into the mechanisms underlying the protective effects of NAC and other potential GPX4-reducing substrates against ferroptosis. Show less

BACKGROUND: Drug repositioning is a pivotal strategy in pharmaceutical research, offering accelerated and cost-effective therapeutic discovery. However, biomedical information relevant to drug repositioning is often complex, dispersed, and underutilized due to limitations in traditional extraction methods, such as reliance on annotated data and poor generalizability. Large language models (LLMs) show promise but face challenges such as hallucinations and interpretability issues. OBJECTIVE: This study proposed long chain-of-thought for drug repositioning knowledge extraction (LCoDR-KE), a lightweight and domain-specific framework to enhance LLMs' accuracy and adaptability in extracting structured biomedical knowledge for drug repositioning. METHODS: A domain-specific schema defined 11 entities (eg, drug, disease) and 18 relationships (eg, treats, is biomarker of). Following the established schema architecture, we constructed automatic annotation based on 10,000 PubMed abstracts via chain-of-thought prompt engineering. A total of 1000 expert-validated abstracts were curated into a drug repositioning corpus, a high-quality specialized corpus, while the remaining entries were allocated for model training purposes. Then, the proposed LCoDR-KE framework combined supervised fine-tuning of the Qwen2.5-7B-Instruct model with reinforcement learning and dual-reward mechanisms. Performance was evaluated against state-of-the-art models (eg, conditional random fields, Bidirectional Encoder Representations From Transformers, BioBERT, Qwen2.5, DeepSeek-R1, OpenBioLLM-70B, and model variants) using precision, recall, and F1-score. In addition, the convergence of the training method was assessed by analyzing performance progression across iteration steps. RESULTS: LCoDR-KE achieved an entity F1 of 81.46% (eg, drug 95.83%, disease 90.52%) and triplet F1 of 69.04%, outperforming traditional models and rivaling larger LLMs (DeepSeek-R1: entity F1=84.64%, triplet F1=69.02%). Ablation studies confirmed the contributions of supervised fine-tuning (8.61% and 20.70% F1 drop if removed) and reinforcement learning (6.09% and 14.09% F1 drop if removed). The training process demonstrated stable convergence, validated through iterative performance monitoring. Qualitative analysis of the model's chain-of-thought outputs showed that LCoDR-KE performed structured and schema-aware reasoning by validating entity types, rejecting incompatible relations, enforcing constraints, and generating compliant JSON. Error analysis revealed 4 main types of mistakes and challenges for further improvement. CONCLUSIONS: LCoDR-KE enhances LLMs' domain-specific adaptability for drug repositioning by offering an open-source drug repositioning corpus and a long chain-of-thought framework based on a lightweight LLM model. This framework supports drug discovery and knowledge reasoning while providing scalable, interpretable solutions applicable to broader biomedical knowledge extraction tasks. Show less

Cancer remains a major global health burden, with rising incidence and mortality linked to aging populations and increased exposure to genotoxic agents. Oxidative stress plays a critical role in cancer development, progression, and resistance to therapy. The nuclear factor erythroid 2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1)-antioxidant response element (ARE) signaling pathway is central to maintaining redox balance by regulating the expression of antioxidant and detoxification genes. Under physiological conditions, this pathway protects cells from oxidative damage, however, sustained activation of NRF2 in cancer, often due to mutations in KEAP1, supports tumor cell survival, drug resistance, and metabolic reprogramming. Recent studies demonstrate that NRF2 enhances glutathione (GSH) synthesis, induces detoxifying enzymes, and upregulates drug efflux transporters, collectively contributing to resistance against chemotherapy and targeted therapies. The inhibition of NRF2 using small molecules or dietary phytochemicals has shown promise in restoring drug sensitivity in preclinical cancer models. This review highlights the dual role of NRF2 in redox regulation and cancer therapy, emphasizing its potential as a therapeutic target. While targeting NRF2 offers a novel approach to overcoming treatment resistance, further research is needed to enhance specificity and facilitate clinical translation. Show less

Carnitine O-acetyltransferase (CRAT) is a key mitochondrial enzyme involved in maintaining metabolic homeostasis by mediating the reversible transfer of acetyl groups between acetyl-CoA and carnitine. This enzymatic activity ensures the optimal functioning of mitochondrial carbon flux by preventing acetyl-CoA accumulation, buffering metabolic flexibility, and regulating the balance between fatty acid and glucose oxidation. CRAT’s interplay with the mitochondrial carnitine shuttle, involving carnitine palmitoyltransferases (CPT1 and CPT2) and the carnitine carrier (SLC25A20), underscores its critical role in energy metabolism. Emerging evidence highlights the structural and functional diversity of CRAT and structurally related acetyltransferases across cellular compartments, illustrating their coordinated role in lipid metabolism, amino acid catabolism, and mitochondrial bioenergetics. Moreover, the structural insights into CRAT have paved the way for understanding its regulation and identifying potential modulators with therapeutic applications for diseases such as diabetes, mitochondrial disorders, and cancer. This review examines CRAT’s structural and functional aspects, its relationships with carnitine shuttle members and other carnitine acyltransferases, and its broader role in metabolic health and disease. The potential for targeting CRAT and its associated pathways offers promising avenues for therapeutic interventions aimed at restoring metabolic equilibrium and addressing metabolic dysfunction in disease states. Show less

Non-small cell lung cancer (NSCLC) is one of the most prevalent and lethal types of cancers worldwide and its high incidence and mortality rates pose a significant public health challenge. Despite significant advances in targeted therapy and immunotherapy, the overall prognosis of patients with NSCLC remains poor. Hypoxia is a critical driving factor in tumor progression, influencing the biological behavior of tumor cells through complex molecular mechanisms. The present review systematically examined the role of the hypoxic microenvironment in NSCLC, demonstrating its crucial role in promoting tumor cell growth, invasion and metastasis. Additionally, it has been previously reported that the hypoxic microenvironment enhances tumor cell resistance by activating hypoxia-inducible factor and regulating exosome secretion. The hypoxic microenvironment also enables tumor cells to adapt to low oxygen and nutrient-deficient conditions by enhancing metabolic reprogramming, such as through upregulating glycolysis. Further studies have shown that the hypoxic microenvironment facilitates immune escape by modulating tumor-associated immune cells and suppressing the antitumor response of the immune system. Moreover, the hypoxic microenvironment increases tumor resistance to radiotherapy, chemotherapy and other types of targeted therapy through various pathways, significantly reducing the therapeutic efficacy of these treatments. Therefore, it could be suggested that early detection of cellular hypoxia and targeted therapy based on hypoxia may offer new therapeutic approaches for patients with NSCLC. The present review not only deepened the current understanding of the mechanisms of action and role of the hypoxic microenvironment in NSCLC but also provided a solid theoretical basis for the future development of precision treatments for patients with NSCLC. Show less

BACKGROUND: Arginine metabolism in tumors is often shunted into the pathway producing pro-tumor and immune suppressive polyamines (PAs), while downmodulating the alternative nitric oxide (NO) synthesis pathway. Aiming to correct arginine metabolism in tumors, arginine deprivation therapy and inhibitors of PA synthesis have been developed. Despite some therapeutic advantages, these approaches have often yielded severe side effects, making it necessary to explore an alternative strategy. We previously reported that supplementing sepiapterin (SEP), the endogenous precursor of tetrahydrobiopterin (BH4, the essential NO synthase cofactor), could correct arginine metabolism in tumor cells and tumor-associated macrophages (TAMs) and induce their metabolic and phenotypic reprogramming. We saw that oral SEP treatment effectively suppressed the growth of HER2-positive mammary tumors in animals. SEP also has no reported dose-dependent toxicity in clinical trials for metabolic disorders. In the present study, we tested our hypothesis that a long-term administration of SEP to individuals susceptible to HER2-positive mammary tumor would protect them against tumor occurrence. METHODS: We administered SEP, in comparison to control DMSO, to MMTV-neu mice susceptible to HER2-positive mammary tumors for 8 months starting at their pre-pubertal stage. We monitored tumor onsets to determine the rate of tumor-free survival. After 8 months of treatment, we grouped animals into DMSO treatment with or without tumors and SEP treatment with or without tumors. We analyzed blood metabolites, PBMC, and bone marrow of DMSO vs. SEP treated animals. RESULTS: We found that a long-term use of SEP in animals susceptible to HER2-positive mammary tumors effectively suppressed tumor occurrence. These SEP-treated animals had undergone reprogramming of the systemic metabolism and immunity, elevating total T cell counts in the circulation and bone marrow. Given that bone marrow-resident T cells are mostly memory T cells, it is plausible that chronic SEP treatment promoted memory T cell formation, leading to a potent tumor prevention. CONCLUSIONS: These findings suggest the possible roles of the SEP/BH4/NO axis in promoting memory T cell formation and its potential therapeutic utility for preventing HER2-positive breast cancer. Show less

Title: Photoinduction of Ferroptosis and cGAS-STING Activation by a H Abstract: Triggering ferroptosis represents a promising anticancer therapeutic strategy, but the development of a selective ferroptosis inducer for cancer-specific therapy remains a great challenge. Herein, a H2S-responsive iridium(III) complex NA-Ir has been well-designed as a ferroptosis inducer. NA-Ir could selectively light up H2S-rich cancer cells, primarily localize in mitochondria, intercalate into mitochondrial DNA (mtDNA), and induce mtDNA damage, exhibiting higher anticancer activity under light irradiation. Mechanistic studies showed that NA-Ir-mediated PDT triggered lipid peroxidation and glutathione peroxidase 4 downregulation through ROS production and GSH depletion, resulting in ferroptosis through multiple pathways. Moreover, the intense mtDNA damage can activate the cyclic GMP-AMP synthase-stimulator of the interferon gene (cGAS-STING) pathway, leading to ferritinophagy and further ferroptosis. RNA-sequencing analysis showed that NA-Ir-mediated PDT mainly affects the expression of genes related to ferroptosis, autophagy, and cancer immunity. This study demonstrates the first cancer-specific example with ferroptosis and cGAS-STING activation, which provides a new strategy for multimodal synergistic therapy. Show less

For decades, great strides have been made in the field of immunometabolism. A plethora of evidence ranging from basic mechanisms to clinical transformation has gradually embarked on immunometabolism to the center stage of innate and adaptive immunomodulation. Given this, we focus on changes in immunometabolism, a converging series of biochemical events that alters immune cell function, propose the immune roles played by diversified metabolic derivatives and enzymes, emphasize the key metabolism-related checkpoints in distinct immune cell types, and discuss the ongoing and upcoming realities of clinical treatment. It is expected that future research will reduce the current limitations of immunotherapy and provide a positive hand in immune responses to exert a broader therapeutic role. Show less

Mitochondria are central actors in diverse physiological phenomena ranging from energy metabolism to stress signaling and immune modulation. Accumulating scientific evidence points to the critical involvement of specific mitochondrial-associated events, including mitochondrial quality control, intercellular mitochondrial transfer, and mitochondrial genetics, in potentiating the metastatic cascade of neoplastic cells. Furthermore, numerous recent studies have consistently emphasized the highly significant role mitochondria play in coordinating the regulation of tumor-infiltrating immune cells and immunotherapeutic interventions. This review provides a comprehensive and rigorous scholarly investigation of this subject matter, exploring the intricate mechanisms by which mitochondria contribute to tumor metastasis and examining the progress of mitochondria-targeted cancer therapies. Show less

We have designed cell-penetrating peptides that target the leucine zipper transcription factors ATF5, CEBPB and CEBPD and that promote apoptotic death of a wide range of cancer cell types, but not normal cells, in vitro and in vivo. Though such peptides have the potential for clinical application, their mechanisms of action are not fully understood. Here, we show that one such peptide, Dpep, compromises glucose uptake and glycolysis in a cell context-dependent manner (in about two-thirds of cancer lines assessed). These actions are dependent on induction of tumor suppressor TXNIP (thioredoxin-interacting protein) mRNA and protein. Knockdown studies show that TXNIP significantly contributes to apoptotic death in those cancer cells in which it is induced by Dpep. The metabolic actions of Dpep on glycolysis led us to explore combinations of Dpep with clinically approved drugs metformin and atovaquone that inhibit oxidative phosphorylation and that are in trials for cancer treatment. Dpep showed additive to synergistic activities in all lines tested. In summary, we find that Dpep induces TXNIP in a cell context-dependent manner that in turn suppresses glucose uptake and glycolysis and contributes to apoptotic death of a range of cancer cells. Show less

Colorectal cancer (CRC) is the third most common cancer worldwide, and the second most common cause of cancer-related death. In 2020, the estimated number of deaths due to CRC was approximately 930000, accounting for 10% of all cancer deaths worldwide. Accordingly, there is a vast amount of ongoing research aiming to find new and improved treatment modalities for CRC that can potentially increase survival and decrease overall morbidity and mortality. Current management strategies for CRC include surgical procedures for resectable cases, and radiotherapy, chemotherapy, and immunotherapy, in addition to their combination, for non-resectable tumors. Despite these options, CRC remains incurable in 50% of cases. Nonetheless, significant improvements in research techniques have allowed for treatment approaches for CRC to be frequently updated, leading to the availability of new drugs and therapeutic strategies. This review summarizes the most recent therapeutic approaches for CRC, with special emphasis on new strategies that are currently being studied and have great potential to improve the prognosis and lifespan of patients with CRC. Show less

The application of artificial intelligence (AI) has been considered a revolutionary change in drug discovery and development. In 2020, the AlphaFold computer program predicted protein structures for the whole human genome, which has been considered a remarkable breakthrough in both AI applications and structural biology. Despite the varying confidence levels, these predicted structures could still significantly contribute to structure-based drug design of novel targets, especially the ones with no or limited structural information. In this work, we successfully applied AlphaFold to our end-to-end AI-powered drug discovery engines, including a biocomputational platform PandaOmics and a generative chemistry platform Chemistry42. A novel hit molecule against a novel target without an experimental structure was identified, starting from target selection towards hit identification, in a cost- and time-efficient manner. PandaOmics provided the protein of interest for the treatment of hepatocellular carcinoma (HCC) and Chemistry42 generated the molecules based on the structure predicted by AlphaFold, and the selected molecules were synthesized and tested in biological assays. Through this approach, we identified a small molecule hit compound for cyclin-dependent kinase 20 (CDK20) with a binding constant Kd value of 9.2 ± 0.5 μM (n = 3) within 30 days from target selection and after only synthesizing 7 compounds. Based on the available data, a second round of AI-powered compound generation was conducted and through this, a more potent hit molecule, ISM042-2-048, was discovered with an average Kd value of 566.7 ± 256.2 nM (n = 3). Compound ISM042-2-048 also showed good CDK20 inhibitory activity with an IC50 value of 33.4 ± 22.6 nM (n = 3). In addition, ISM042-2-048 demonstrated selective anti-proliferation activity in an HCC cell line with CDK20 overexpression, Huh7, with an IC50 of 208.7 ± 3.3 nM, compared to a counter screen cell line HEK293 (IC50 = 1706.7 ± 670.0 nM). This work is the first demonstration of applying AlphaFold to the hit identification process in drug discovery. Show less

The great clinical success of cisplatin and its derivatives has convinced people that metal complexes could play a more significant role in human cancer therapy. However, targeting and drug resistance are still two dominant problems that need to be urgently solved for metallodrugs’ efficacy and clinical translation. As an important component of metal complexes, organometallics have been experiencing rapid development in recent years. Compared with platinum drugs, emerging anti-tumor organometallics targeting dynamic bioprocesses provide an effective strategy to overcome conventional problems. This review focuses on burgeoning anti-tumor strategies and provides up-to-date advances in anti-tumor organometallics development based on their action mechanisms. Specifically, important tumor-overexpressed proteins and nucleic acids as organometallics’ anti-tumor targets are systematically presented, followed by organometallics that exert their anti-tumor activity by perturbing tumor intracellular energy/redox/metal/immune homeostasis. Finally, nine cell death pathways including apoptosis, paraptosis, autophagy, oncosis, necrosis, necroptosis, ferroptosis, pyroptosis, and immunogenic cell death (ICD) that can be induced by organometallics are reviewed, and their morphological and biochemical features are summarised. This review at the interface of chemistry, biology, and medicine aims to enlighten the rational development of organometallic anti-tumor agents. Show less

Lung cancer is a common malignant tumor that occurs in the human body and poses a serious threat to human health and quality of life. The existing treatment methods mainly include surgical treatment, chemotherapy, and radiotherapy. However, due to the strong metastatic characteristics of lung cancer and the emergence of related drug resistance and radiation resistance, the overall survival rate of lung cancer patients is not ideal. There is an urgent need to develop new treatment strategies or new effective drugs to treat lung cancer. Ferroptosis, a novel type of programmed cell death, is different from the traditional cell death pathways such as apoptosis, necrosis, pyroptosis and so on. It is caused by the increase of iron-dependent reactive oxygen species due to intracellular iron overload, which leads to the accumulation of lipid peroxides, thus inducing cell membrane oxidative damage, affecting the normal life process of cells, and finally promoting the process of ferroptosis. The regulation of ferroptosis is closely related to the normal physiological process of cells, and it involves iron metabolism, lipid metabolism, and the balance between oxygen-free radical reaction and lipid peroxidation. A large number of studies have confirmed that ferroptosis is a result of the combined action of the cellular oxidation/antioxidant system and cell membrane damage/repair, which has great potential application in tumor therapy. Therefore, this review aims to explore potential therapeutic targets for ferroptosis in lung cancer by clarifying the regulatory pathway of ferroptosis. Based on the study of ferroptosis, the regulation mechanism of ferroptosis in lung cancer was understood and the existing chemical drugs and natural compounds targeting ferroptosis in lung cancer were summarized, with the aim of providing new ideas for the treatment of lung cancer. In addition, it also provides the basis for the discovery and clinical application of chemical drugs and natural compounds targeting ferroptosis to effectively treat lung cancer. Show less

Introduction: Drugs targeting mitochondria are emerging as promising antitumor therapeutics in preclinical models. However, a few of these drugs have shown clinical toxicity. Developing mitochondria-targeted modified natural compounds and US FDA-approved drugs with increased therapeutic index in cancer is discussed as an alternative strategy. Areas Covered: Triphenylphosphonium cation (TPP + )-based drugs selectively accumulate in the mitochondria of cancer cells due to their increased negative membrane potential, target the oxidative phosphorylation proteins, inhibit mitochondrial respiration, and inhibit tumor proliferation. TPP + -based drugs exert minimal toxic side effects in rodents and humans. These drugs can sensitize radiation and immunotherapies. Expert Opinion: TPP + -based drugs targeting the tumor mitochondrial electron transport chain are a new class of oxidative phosphorylation inhibitors with varying antiproliferative and antimetastatic potencies. Some of these TPP + -based agents, which are synthesized from naturally occurring molecules and FDA-approved drugs, have been tested in mice and did not show notable toxicity, including neurotoxicity, when used at doses under the maximally tolerated dose. Thus, more effort should be directed toward the clinical translation of TPP + -based OXPHOS-inhibiting drugs in cancer prevention and treatment. Show less