Targeting cancer cells by ROS-mediated mechanisms: a radical therapeutic approach? Nat Rev Drug Discov. 2009;8:579-591. [PMID: 19478820 DOI: 10.1038/nrd2803]

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.

Engineered low-pathogenic Helicobacter pylori as orally tumor immunomodulators for the stimulation of systemic immune response

Gastric cancer constitutes a malignant neoplasm characterized by heightened invasiveness, posing significant global health threat. Inspired by the analysis that gastric cancer patients with Helicobacter pylori (H. pylori) infection have higher overall survival, whether H. pylori can be used as therapeutics agent and oral drug delivery system for gastric cancer. Hence, we constructed engineered H. pylori for gastric cancer treatment. A type Ⅱ H. pylori with low pathogenicity, were conjugated with photosensitizer to develop the engineered living bacteria NIR-triggered system (Hp-Ce6). Hp-Ce6 could maintain activity in stomach acid, quickly infiltrate through mucus layer and finally migrate to tumor region owing to the cell morphology and urease of H. pylori. H. pylori, accumulated in the tumor site, severed as vaccine to activate cGAS-STING pathway, and synergistically remodel the macrophages phenotype. Upon irradiation within stomach, Hp-Ce6 directly destroyed tumor cells via photodynamic effect inherited by Ce6, companied by inducing immunogenic tumor cell death. Additionally, Hp-Ce6 exhibited excellent biosafety with fecal elimination and minimal blood absorption. This work explores the feasibility and availability of H. pylori-based oral delivery platforms for gastric tumor and further provides enlightening strategy to utilize H. pylori invariably presented in the stomach as in-situ immunomodulator to enhance antitumor efficacy.

A peptide-salinomycin conjugate with a bystander effect reduces the stemness characteristics of ovarian cancer cells and enhances drug sensitivity

Salinomycin (Sal) has attracted considerable attention in the field of tumor treatment, especially for its inhibitory effect on cancer stem cells (CSCs) and drug-resistant tumor cells. However, its solubility and targeting specificity pose significant challenges to its pharmaceutical development. Sal-A6, a novel peptide-drug conjugate (PDC), was formed by linking the peptide A6 targeting the CSC marker CD44 with Sal using a specific linker. This conjugation markedly enhances the physicochemical properties of Sal and compared to Sal, Sal-A6 demonstrated a significantly increased activity against ovarian cancer. Furthermore, Sal-A6, employing a disulfide bond as a linker, exhibited bystander killing effect. Moreover, it induces substantial cytotoxic effect on both cancer stem cells and drug-resistant cells in addition to enhance chemosensitivity of resistant ovarian cancer cells. In summary, the results indicated that Sal-A6, a novel PDC derived from Sal, has potential therapeutic applications in the treatment of ovarian cancer and drug-resistant patients. Additionally, this discovery offers insights for developing PDC-type drugs using Sal as a foundation.

Hydrogen peroxide responsive theranostics for cancer-selective activation of DNA alkylators and real-time fluorescence monitoring in living cells

Triple negative breast cancer (TNBC) is a notoriously difficult disease to treat, and many of the existing TNBC chemotherapeutics lack tumor selectivity and the capability for simultaneously visualizing and monitoring their own activity in the biological context. However, TNBC cells have been known to generate high levels of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). To this end, three novel small molecule theranostics 1a, 1c, and 2 consisting of both H2O2-responsive nitrogen mustard prodrug and profluorophore character have been designed, synthesized, and evaluated as targeted cancer therapeutics and bioimaging agents. The three theranostics comprise of boronate esters that deactivate nitrogen mustard functional groups and fluorophores but allow their selective activation through H2O2-specific oxidative deboronation for the release of the active drug and fluorophore. The three theranostics demonstrated H2O2-inducible DNA-alkylating capability and fluorescence turn-on properties in addition to selective anticancer activity. They are particularly effective in killing TNBC MDA-MB-468 cells with high H2O2 level while safe to normal epithelial MCF-10A cell. The conjugated boron-masked fluorophores in 1c and 2 are highly responsive towards H2O2, which enabled tracking of the theranostics in living cellular mitochondria and nucleus organelles. The three theranostics 1a, 1c, and 2 are capable of both selective release of the active drug to take effect in H2O2-rich cancer sites and simultaneously monitoring its activity. This single molecule system is of utmost importance to understand the function, efficacy, and mechanism of the H2O2-activated prodrugs and theranostics within the living recipient.

Three Ru(II) complexes modulate the antioxidant transcription factor Nrf2 to overcome cisplatin resistance

Here, we designed, synthesized and characterized three new cyclometalated Ru(II) complexes, [Ru(phen)2(1-(4-Ph-Ph)-IQ)]+ (phen = 1,10-phenanthroline, IQ = isoquinoline, RuIQ9), [Ru(phen)2(1-(4-Ph-Ph)-7-OCH3-IQ)]+ (RuIQ10), and [Ru(phen)2(1-(4-Ph-Ph)-6,7-(OCH3)2-IQ)]+ (RuIQ11). The cytotoxicity experiments conducted on both 2D and 3D multicellular tumor spheroids (MCTSs) indicated that complexes RuIQ9-11 exhibited notably higher cytotoxicity against A549 and A549/DDP cells when compared to the ligands and precursor compounds as well as clinical cisplatin. Moreover, the Ru(II) complexes displayed low toxicity when tested on normal HBE cells in vitro and exposed to zebrafish embryos in vivo. In addition, complexes RuIQ9-11 could inhibit A549 and A549/DDP cell migration and proliferation by causing cell cycle arrest, mitochondrial dysfunction, and elevating ROS levels to induce apoptosis in these cells. Mechanistic studies revealed that RuIQ9-11 could suppress the expression of Nrf2 and its downstream antioxidant protein HO-1 by inhibiting Nrf2 gene transcription in drug-resistant A549/DDP cells. Simultaneously, they inhibited the expression of efflux proteins MRP1 and p-gp in drug-resistant cells, ensuring the accumulation of the complexes within the cells. This led to an increase in intracellular ROS levels in drug-resistant cells, ultimately causing damage and cell death, thus overcoming cisplatin resistance. More importantly, RuIQ11 could effectively inhibit the migration and proliferation of drug-resistant cells within zebrafish, addressing the issue of cisplatin resistance. Accordingly, the prepared Ru(II) complexes possess significant potential for development as highly effective and low-toxicity lung cancer therapeutic agents to overcome cisplatin resistance.

Extra-nuclear TERT counteracts oxidative stress and promotes progression in papillary thyroid carcinoma

The reactivation of TERT is associated with poor outcome in papillary thyroid cancer (PTC). Extra-telomeric functions of TERT were reported, with a protective role against oxidative stress (OS). The aim of the present study was to explore the extra-nuclear TERT localization in PTC and its role in cancer progression. TERT nuclear export under OS were analyzed in K1 PTC cell line. We investigated the role of different TERT localizations using specific TERT constructs that limit its localization to the nucleus or to the mitochondria. The effect of SRC kinase inhibitor PP2, which reduces TERT nuclear export, was investigated as well. Moreover, TERT localization was analyzed in 39 PTC tissues and correlated with the genetic profile and the level of OS, DNA damage and apoptosis in the tumors and with the clinical characteristics of the patients. We demonstrated that TERT is exported from the nucleus in response to OS induced either from H2O2 or the BRAF inhibitor PLX4720. We proved that extra-nuclear TERT reduces mitochondrial OS and induces mitochondrial fragmentation. Moreover, limiting mitochondrial TERT localization reduced proliferation, migration, AKT phosphorylation and glycolysis and increased DNA damage and p21 expression. Finally, in PTC tissues the fraction of mitochondrial/nuclear TERT resulted inversely correlated with OS and p21 expression and associated with tumor persistence. In conclusion, our data indicate that extra-nuclear TERT is involved in reducing the effect of excessive OS, thus promoting cancer cell survival. Extra-nuclear TERT may thus represent a marker of cancer progression and a possible therapeutic target in PTC.

Trehalose enhanced cold atmospheric plasma-mediated cancer treatment

Cold atmospheric plasma (CAP) is a unique form of physical plasma that has shown great potential for cancer therapy. CAP uses ionized gas to induce lethal oxidative stress on cancer cells; however, the efficacy of CAP therapy continues to be improved. Here, we report an injectable hydrogel-mediated approach to enhance the anti-tumor efficacy of CAP by regulating the phosphorylation of eIF2α. We discovered that reactive oxygen and nitrogen species (ROS/RNS), two main anti-tumor components in CAP, can lead to lethal oxidative stress on tumor cells. Elevated oxidative stress subsequently induces eIF2α phosphorylation, a pathognomonic marker of immunogenic cell death (ICD). Trehalose, a natural disaccharide sugar, can further enhance CAP-induced ICD by elevating the phosphorylation of eIF2α. Moreover, injectable hydrogel-mediated delivery of CAP/trehalose treatment promoted dendritic cell (DC) maturation, initiating tumor-specific T-cell mediated anti-tumor immune responses. The combination therapy also supported the polarization of tumor-associated macrophages to an M1-like phenotype, reversing the immunosuppressive tumor microenvironment and promoting tumor antigen presentation to T cells. In combination with immune checkpoint inhibitors (i.e., anti-programmed cell death protein 1 antibody, aPD1), CAP/trehalose therapy further inhibited tumor growth. Importantly, our findings also indicated that this hydrogel-mediated local combination therapy engaged the host systemic innate and adaptive immune systems to impair the growth of distant tumors.

Synthesis and anti-proliferative effect of novel 4-Aryl-1, 3-Thiazole-TPP conjugates via mitochondrial uncoupling process

With the advent of mitochondrial targeting moiety such as triphenlyphosphonium cation (TPP+), targeting mitochondria in cancer cells has become a promising strategy for combating tumors. Herein, a series of novel 4-aryl-1,3-thiazole derivatives linked to TPP+ moiety were designed and synthesized. The cytotoxicity against a panel of four cancer cell lines was evaluated by CCK-8 assay. Most of these compounds exhibited moderate to good inhibitory activity over HeLa, PC-3 and HCT-15 cells while MCF-7 cells were less sensitive to most compounds. Among them, compound 12a exhibited a significant anti-proliferative activity against HeLa cells, and prompted for further investigation. Specifically, 12a decreased mitochondrial membrane potential and enhanced levels of reactive oxygen species (ROS). The flow cytometry analysis revealed that compound 12a could induce apoptosis and cell cycle arrest at G0/G1 phase in HeLa cells. In addition, mitochondrial bioenergetics assay revealed that 12a displayed mild mitochondrial uncoupling effect. Taken together, these findings suggest the therapeutic potential of compound 12a as an antitumor agent targeting mitochondria.

A promising future of metal-N-heterocyclic carbene complexes in medicinal chemistry: The emerging bioorganometallic antitumor agents

Metal complexes based on N-heterocyclic carbene (NHC) ligands have emerged as promising broad-spectrum antitumor agents in bioorganometallic medicinal chemistry. In recent decades, studies on cytotoxic metal-NHC complexes have yielded numerous compounds exhibiting superior cytotoxicity compared to cisplatin. Although the molecular mechanisms of these anticancer complexes are not fully understood, some potential targets and modes of action have been identified. However, a comprehensive review of their biological mechanisms is currently absent. In general, apoptosis caused by metal-NHCs is common in tumor cells. They can cause a series of changes after entering cells, such as mitochondrial membrane potential (MMP) variation, reactive oxygen species (ROS) generation, cytochrome c (cyt c) release, endoplasmic reticulum (ER) stress, lysosome damage, and caspase activation, ultimately leading to apoptosis. Therefore, a detailed understanding of the influence of metal-NHCs on cancer cell apoptosis is crucial. In this review, we provide a comprehensive summary of recent advances in metal-NHC complexes that trigger apoptotic cell death via different apoptosis-related targets or signaling pathways, including B-cell lymphoma 2 (Bcl-2 family), p53, cyt c, ER stress, lysosome damage, thioredoxin reductase (TrxR) inhibition, and so forth. We also discuss the challenges, limitations, and future directions of metal-NHC complexes to elucidate their emerging application in medicinal chemistry.

AMPK activation reduces cancer cell aggressiveness via inhibition of monoamine oxidase A (MAO-A) expression/activity

AIM

AMPK can be considered as an important target molecule for cancer for its unique ability to directly recognize cellular energy status. The main aim of this study is to explore the role of different AMPK activators in managing cancer cell aggressiveness and to understand the mechanistic details behind the process.

MAIN METHODS

First, we explored the AMPK expression pattern and its significance in different subtypes of lung cancer by accessing the TCGA data sets for LUNG, LUAD and LUSC patients and then established the correlation between AMPK expression pattern and overall survival of lung cancer patients using Kaplan-Meire plot. We further carried out several cell-based assays by employing different wet lab techniques including RT-PCR, Western Blot, proliferation, migration and invasion assays to fulfil the aim of the study.

KEY FINDINGS

SIGNIFICANCE: This study identifies the importance of AMPK activators as a repurposing agent for combating lung and colon cancer cell aggressiveness. It also suggests SRT-1720 as a potent repurposing agent for cancer treatment especially in NSCLC patients where a point mutation is present in LKB1.

Cytotoxic and radical activities of metal-organic framework modified with iron oxide: Biological and physico-chemical analyses

Metal-organic framework (MOF) modified with iron oxide, Fe3O4-MOF, is a perspective drug delivery agent, enabling magnetic control and production of active hydroxyl radicals, •OH, via the Fenton reaction. This paper studies cytotoxic and radical activities of Fe-containing nanoparticles (NPs): Fe3O4-MOF and its components - bare Fe3O4 and MOF (MIL-88B). Luminous marine bacteria Photobacteriumphosphoreum were used as a model cellular system to monitor bioeffects of the NPs. Neither the NPs of Fe3O4-MOF nor MOF showed cytotoxic effects in a wide range of concentrations (<10 mg/L); while Fe3O4 was toxic at >3·10-3 mg/L. The NPs of Fe3O4 did not affect the bacterial bioluminescence enzymatic system; their toxic effect was attributed to cellular membrane processes. The integral content of reactive oxygen species (ROS) was determined using a chemiluminescence luminol assay. Bacteria mitigated excess of ROS in water suspensions of Fe3O4-MOF and MOF, maintaining bioluminescence intensity closer to the control; this resulted in low toxicity of these NPs. We estimated the activity of •OH radicals in the NPs samples with physical and chemical methods - spin capture technology (using electron paramagnetic resonance spectroscopy) and methylene blue degradation. Physico-chemical interpretation of cellular responses is provided in terms of iron content, iron ions release and •OH radical production.

Natural products for enhancing the sensitivity or decreasing the adverse effects of anticancer drugs through regulating the redox balance

Redox imbalance is reported to play a pivotal role in tumorigenesis, cancer development, and drug resistance. Severe oxidative damage is a general consequence of cancer cell responses to treatment and may cause cancer cell death or severe adverse effects. To maintain their longevity, cancer cells can rescue redox balance and enter a state of resistance to anticancer drugs. Therefore, targeting redox signalling pathways has emerged as an attractive and prospective strategy for enhancing the efficacy of anticancer drugs and decreasing their adverse effects. Over the past few decades, natural products (NPs) have become an invaluable source for developing new anticancer drugs due to their high efficacy and low toxicity. Increasing evidence has demonstrated that many NPs exhibit remarkable antitumour effects, whether used alone or as adjuvants, and are emerging as effective approaches to enhance sensitivity and decrease the adverse effects of conventional cancer therapies by regulating redox balance. Among them are several novel anticancer drugs based on NPs that have entered clinical trials. In this review, we summarize the synergistic anticancer effects and related redox mechanisms of the combination of NPs with conventional anticancer drugs. We believe that NPs targeting redox regulation will represent promising novel candidates and provide prospects for cancer treatment in the future.

Enzyme-Dynamic Extracellular Vesicles for Metalloimmunotherapy of Malignant Pleural Effusions

Malignant pleural effusions (MPEs) are hard to treat, and their onset usually signals terminal cancer. Immunotherapies hold promise but must overcome the immunosuppressive MPE microenvironment. Herein, we treat MPEs via synergistically combining two emerging cancer therapy modalities: enzyme-dynamic therapy (EDT) and metalloimmunotherapy. To do so, a nanoplatform termed "A-R-SOME" was developed which comprises MPE-targeted M1 type extracellular vesicles (EVs) loaded with (1) a manganese-based superoxide dismutase (SOD) enzyme, (2) stimulator of interferon genes (STING) agonist diABZI-2, and (3) signal transducer and an activator of transcription 3 (STAT3) small interfering RNA. Endogenous reactive oxygen species within tumors induced immunogenic cell death by EDT, along with STING activation by both Mn and diABZI-2, and suppression of the STAT3 pathway. Systemically administered A-R-SOME alleviated the MPE immunosuppressive microenvironment, triggered antitumor systemic immunity, and long-term immune memory, leading to the complete eradication of MPE and pleural tumors with 100% survival rate in an aggressive murine model. A-R-SOME-induced immune effects were also observed in human patient-derived MPE, pointing toward the translation potential of A-R-SOME as an experimental malignancy treatment.

Four Birds with One Stone: A Bandgap-Regulated Multifunctional Schottky Heterojunction for Robust Synergistic Antitumor Therapy upon Endo-/Exogenous Stimuli

Considering the profound impact of structure on heterojunction catalysts, the rational design of emerging catalysts with optimized energy band structures is required for antitumor efficiency. Herein, we select titanium nitride (TiN) and Pt to develop a multifunctional Schottky heterojunction named Pt/H-TiN&SRF (PHTS) nanoparticles (NPs) with a narrowed bandgap to accomplish "four birds with one stone" involving enzyo/sono/photo three modals and additional ferroptosis. The in situ-grown Pt NPs acted as electron traps that can cause the energy band to bend upward and form a Schottky barrier, thereby facilitating the separation of electron/hole pairs in exogenous stimulation catalytic therapy. In addition, endogenous catalytic reactions based on peroxidase (POD)- and catalase (CAT)-mimicking activities can also be amplified, triggering intense oxidative stress, in which CAT-like activity decomposes endogenous H2O2 into O2 alleviating hypoxia and provides reactants for sonodynamic therapy. Moreover, PHTS NPs can elicit mild photothermal therapy with boosted photothermal properties as well as ferroptosis with loaded ferroptosis inducer sorafenib for effective tumor ablation and apoptosis-ferroptosis synergistic tumor inhibitory effect. In summary, this paper proposes an attractive design for antitumor strategies and highlights findings for heterojunction catalytic therapy with potential in tumor theranostics.

Current status and trend of mitochondrial research in lung cancer: A bibliometric and visualization analysis

This study summarizes and analyzes the relationship between mitochondria and the pathogenesis of lung cancer. The related articles in the Web of Science core literature database are searched and collected, and the data are processed by R software, Citespace, VOSviewer, and Excel. A total of 4476 related papers were retrieved, 4476 articles from 20162 co-authors of 3968 institutions in 84 countries and published in 951 journals. Through various bibliometric analysis tools, the relationship between mitochondria and the pathogenesis of lung cancer was analyzed, the previous research results were summarized, and the potential research direction was found.

Blocking Metallothionein-2 Expression by Copper-Doped Carbon Dots Induces Cellular Antioxidant System Collapse for Antitumor Therapy

The insufficient antioxidant reserves in tumor cells play a critical role in reactive oxygen species (ROS)-mediated therapeutics. Metallothionein-2 (MT-2), an intracellular cysteine-rich protein renowned for its potent antioxidant properties, is intricately involved in tumor development and correlates with a poor prognosis. Consequently, MT-2 emerges as a promising target for tumor therapy. Herein, we present the development of copper-doped carbon dots (Cu-CDs) to target MT-2 to compromise the delicate antioxidant reserves in tumor cells. These Cu-CDs with high tumor accumulation and prolonged body retention can effectively suppress tumor growth by inducing oxidative stress. Transcriptome sequencing unveils a significant decrease in MT-2 expression within the in vivo tumor samples. Further mechanical investigations demonstrate that the antitumor effect of Cu-CDs is intricately linked to apolipoprotein E (ApoE)-mediated downregulation of MT-2 expression and the collapse of the antioxidant system. The robust antitumor efficacy of Cu-CDs provides invaluable insights into developing MT-2-targeted nanomedicine for cancer therapies.

NIR-II-Responsive Versatile Nanozyme Based on H2O2 Cycling and Disrupting Cellular Redox Homeostasis for Enhanced Synergistic Cancer Therapy

Disturbing cellular redox homeostasis within malignant cells, particularly improving reactive oxygen species (ROS), is one of the effective strategies for cancer therapy. The ROS generation based on nanozymes presents a promising strategy for cancer treatment. However, the therapeutic efficacy is limited due to the insufficient catalytic activity of nanozymes or their high dependence on hydrogen peroxide (H2O2) or oxygen. Herein, we reported a nanozyme (CSA) based on well-defined CuSe hollow nanocubes (CS) uniformly covered with Ag nanoparticles (AgNPs) to disturb cellular redox homeostasis and catalyze a cascade of intracellular biochemical reactions to produce ROS for the synergistic therapy of breast cancer. In this system, CSA could interact with the thioredoxin reductase (TrxR) and deplete the tumor microenvironment-activated glutathione (GSH), disrupting the cellular antioxidant defense system and augmenting ROS generation. Besides, CSA possessed high peroxidase-mimicking activity toward H2O2, leading to the generation of various ROS including hydroxyl radical (•OH), superoxide radicals (•O2-), and singlet oxygen (1O2), facilitated by the Cu(II)/Cu(I) redox and H2O2 cycling, and plentiful catalytically active metal sites. Additionally, due to the absorption and charge separation performance of AgNPs, the CSA exhibited excellent photothermal performance in the second near-infrared (NIR-II, 1064 nm) region and enhanced the photocatalytic ROS level in cancer cells. Owing to the inhibition of TrxR activity, GSH depletion, high peroxidase-mimicking activity of CSA, and abundant ROS generation, CSA displays remarkable and specific inhibition of tumor growth.

G2A as a key modulator of carbonyl stress and apoptosis resistance in glucose-loaded cancer cells

Cancer cells exhibit high glycolytic activity, metabolizing glucose as their primary energy substrate. Toxic metabolites produced during glycolysis, such as methylglyoxal, induce carbonyl stress (CS), promoting inflammation and oxidative stress. The elevated glucose metabolism in cancer cells creates this toxic environment. However, little research has focused on the molecules mediating these reactions and stresses, and their role in selecting and enriching apoptosis-resistant cells. This study investigated the impact of constitutively suppressing oxidized lipid receptor G2A (GPR132) expression on the relationship between CS and oxidative stress in glucose-loaded cancer cells. G2A has recently attracted attention as a tumor promoter. However, our study shows that G2A suppression under glucose loading significantly reduces CS and associated oxidative stress, thereby enhancing cancer cell survival. This suggests a new mechanism contrary to conventional thinking, involving the acute induction of glyoxalase 1 (Glo1). G2A may thus play a role in selecting and enriching apoptosis-resistant cell populations under high glucose conditions by regulating Glo1 expression. These findings improve our understanding of the adaptive capacity of cancer cells to glucose toxicity.

Saikosaponin D potentiates the antineoplastic effects of doxorubicin in drug-resistant breast cancer through perturbing NQO1-mediated intracellular redox balance

BACKGROUND

Drug resistance to doxorubicin (DOX) significantly limits its therapeutic efficacy in breast cancer (BC) patients. Saikosaponin D (SSD), a triterpene saponin derived from the traditional herb Radix Bupleuri, has shown promise as a chemotherapeutic sensitizer in preclinical studies due to its notable antitumor activity. However, the role and mechanism of SSD in DOX-resistant BC cells remain largely unexplored.

PURPOSE

This study aimed to investigate the chemosensitizing effect of SSD on DOX-resistant BC and the underlying molecular mechanisms both in vitro and in vivo.

METHODS

In vitro assays, including cell viability, clone formation, three-dimensional tumor spheroid growth, and apoptosis analysis, were conducted to evaluate the synergistic effect of SSD and DOX on resistant BC cells. Reactive oxygen species (ROS), GSH/GSSG, NADPH/NADP+, and NADH/NAD+ detections were employed to assess the impact of SSD on cellular redox homeostasis. Western blotting, cell cycle distribution assay, and DOX uptake assay were performed to further elucidate the possible antineoplastic mechanism of SSD. Finally, a subcutaneous MCF7/DOX cell xenografted model in nude mice was established to identify the in vivo anticarcinogenic effect of SSD combined with DOX.

RESULTS

SSD significantly inhibited cell viability, proliferation, and clone formation, enhancing DOX's anticancer efficacy in vitro and in vivo. Mechanistically, SSD reduced STAT1, NQO1, and PGC-1α protein levels, leading to cellular redox imbalance, excessive ROS generation, and depletion of GSH, NADPH, and NADH. SSD induced DNA damage by disrupting redox homeostasis, resulting in G0/G1 phase cell cycle arrest. Additionally, SSD increased DOX accumulation in BC cells via inhibiting P-gp protein expression and efflux activity.

CONCLUSION

We demonstrated for the first time that SSD enhances the sensitivity of chemoresistant BC cells to DOX by disrupting cellular redox homeostasis through inactivation of the STAT1/NQO1/PGC-1α signaling pathway. This study provides evidence for SSD as an adjuvant agent in drug-resistant BC treatment.

Recent advances for enhanced photodynamic therapy: from new mechanisms to innovative strategies

Photodynamic therapy (PDT) has been developed as a potential cancer treatment approach owing to its non-invasiveness, spatiotemporal control and limited side effects. Currently, great efforts have been made to improve the PDT effect in terms of safety and efficiency. In this review, we highlight recent advances in innovative strategies for enhanced PDT, including (1) the development of novel radicals, (2) design of activatable photosensitizers based on the TME and light, and (3) photocatalytic NADH oxidation to damage the mitochondrial electron transport chain. Additionally, the new mechanisms for PDT are also presented as an inspiration for the design of novel PSs. Finally, we discuss the current challenges and future prospects in the clinical practice of these innovative strategies. It is hoped that this review will provide a new angle for understanding the relationship between the intratumoural redox environment and PDT mechanisms, and new ideas for the future development of smart PDT systems.

Applications of nanotechnology in remodeling the tumour microenvironment for glioblastoma treatment

With the increasing research and deepening understanding of the glioblastoma (GBM) tumour microenvironment (TME), novel and more effective therapeutic strategies have been proposed. The GBM TME involves intricate interactions between tumour and non-tumour cells, promoting tumour progression. Key therapeutic goals for GBM treatment include improving the immunosuppressive microenvironment, enhancing the cytotoxicity of immune cells against tumours, and inhibiting tumour growth and proliferation. Consequently, remodeling the GBM TME using nanotechnology has emerged as a promising approach. Nanoparticle-based drug delivery enables targeted delivery, thereby improving treatment specificity, facilitating combination therapies, and optimizing drug metabolism. This review provides an overview of the GBM TME and discusses the methods of remodeling the GBM TME using nanotechnology. Specifically, it explores the application of nanotechnology in ameliorating immune cell immunosuppression, inducing immunogenic cell death, stimulating, and recruiting immune cells, regulating tumour metabolism, and modulating the crosstalk between tumours and other cells.

Nrf2-Mediated Antioxidant Response and Drug Efflux Transporters Upregulation as Possible Mechanisms of Resistance in Photodynamic Therapy of Cancers

Photodynamic therapy (PDT) is a groundbreaking approach involving the induction of cytotoxic reactive oxygen species (ROS) within tumors through visible light activation of photosensitizers (PS) in the presence of molecular oxygen. This innovative therapy has demonstrated success in treating various cancers. While PDT proves highly effective in most solid tumors, there are indications that certain cancers exhibit resistance, and some initially responsive cancers may develop intrinsic or acquired resistance to PDT. The molecular mechanisms underlying this resistance are not fully understood. Recent evidence suggests that, akin to other traditional cancer treatments, the activation of survival pathways, such as the KEAP1/Nrf2 signaling pathway, is emerging as an important mechanism of post-PDT resistance in many cancers. This article explores the dual role of Nrf2, highlighting evidence linking aberrant Nrf2 expression to treatment resistance across a range of cancers. Additionally, it delves into the specific role of Nrf2 in the context of photodynamic therapy for cancers, emphasizing evidence that suggests Nrf2-mediated upregulation of antioxidant responses and induction of drug efflux transporters are potential mechanisms of resistance to PDT in diverse cancer types. Therefore, understanding the specific role(s) of Nrf2 in PDT resistance may pave the way for the development of more effective cancer treatments using PDT.

Cold atmospheric plasma enhances SLC7A11-mediated ferroptosis in non-small cell lung cancer by regulating PCAF mediated HOXB9 acetylation

Lung cancer is a leading cause of cancer death worldwide, with high incidence and poor survival rates. Cold atmospheric plasma (CAP) technology has emerged as a promising therapeutic approach for cancer treatment, inducing oxidative stress in malignant tissues without causing thermal damage. However, the role of CAP in regulating lung cancer cell ferroptosis remains unclear. Here, we observed that CAP effectively suppressed the growth and migration abilities of lung cancer cells, with significantly increased ferroptotic cell death, lipid peroxidation, and decreased mitochondrial membrane potential. Mechanistically, CAP regulates SLC7A11-mediated cell ferroptosis by modulating HOXB9. SLC7A11, a potent ferroptosis suppressor, was markedly reduced by HOXB9 knockdown, while it was enhanced by overexpressing HOXB9. The luciferase and ChIP assays confirmed that HOXB9 can directly target SLC7A11 and regulate its gene transcription. Additionally, CAP enhanced the acetylation modification level of HOXB9 by promoting its interaction with acetyltransferase p300/CBP-associated factor (PCAF). Acetylated HOXB9 affects its protein ubiquitination modification level, which in turn affects its protein stability. Notably, the upregulation of SLC7A11 and HOXB9 mitigated the suppressive effects of CAP on ferroptosis status, cell proliferation, invasion, and migration in lung cancer cells. Furthermore, animal models have also confirmed that CAP can inhibit the progression of lung cancer in vivo. Overall, this study highlights the significance of the downregulation of the HOXB9/SLC7A11 axis by CAP treatment in inhibiting lung cancer, offering novel insights into the potential mechanisms and therapeutic strategies of CAP for lung cancer.

Mitochondrial signaling pathways and their role in cancer drug resistance

Mitochondria, traditionally known as cellular powerhouses, now emerge as critical signaling centers influencing cancer progression and drug resistance. The review highlights the role that apoptotic signaling, DNA mutations, mitochondrial dynamics and metabolism play in the development of resistance mechanisms and the advancement of cancer. Targeted approaches are discussed, with an emphasis on managing mitophagy, fusion, and fission of the mitochondria to make resistant cancer cells more susceptible to traditional treatments. Additionally, metabolic reprogramming can be used to effectively target metabolic enzymes such GLUT1, HKII, PDK, and PKM2 in order to avoid resistance mechanisms. Although there are potential possibilities for therapy, the complex structure of mitochondria and their subtle role in tumor development hamper clinical translation. Novel targeted medicines are put forth, providing fresh insights on combating drug resistance in cancer. The study also emphasizes the significance of glutamine metabolism, mitochondrial respiratory complexes, and apoptotic pathways as potential targets to improve treatment effectiveness against drug-resistant cancers. Combining complementary and nanoparticle-based techniques to target mitochondria has demonstrated encouraging results in the treatment of cancer, opening doors to reduce resistance and enable individualized treatment plans catered to the unique characteristics of each patient. Suggesting innovative approaches such as drug repositioning and mitochondrial drug delivery to enhance the efficacy of mitochondria-targeting therapies, presenting a pathway for advancements in cancer treatment. This thorough investigation is a major step forward in the treatment of cancer and has the potential to influence clinical practice and enhance patient outcomes.

An Outlook on Platinum-Based Active Ingredients for Dermatologic and Skincare Applications

Platinum-based materials exhibit a broad spectrum of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and pro-collagen synthesis properties, making them particularly useful for various biomedical applications. This review summarizes the biological effects and therapeutic potential of platinum-based active ingredients in dermatological and skincare applications. We discuss their synthesis methods and their antioxidant, anti-inflammatory, antimicrobial, and collagen synthesis properties, which play essential roles in treating skin conditions including psoriasis and acne, as well as enhancing skin aesthetics in anti-aging products. Safety and sustainability concerns, including the need for green synthesis and comprehensive toxicological assessments to ensure safe topical applications, are also discussed. By providing an up-to-date overview of current research, we aim to highlight both the potential and the current challenges of platinum-based active ingredients in advancing dermatology and skincare solutions.

Fabrication of Nanocatalytic Medicine from Self-Assembling Peptides Containing an ATCUN-Like Copper-Binding Motif for Anticancer Therapy

Development of nanomaterials with multiple enzymatic activities via a facile approach receives growing interests in recent years. Although peptide self-assembling provides an effective approach for the construction of biomimetic materials in recent years, fabrication of artificial enzymes from self-assembling peptides with multiple catalytic activities for anticancer therapy is still a challenge. Here, we report a simple method to prepare nanocatalysts with multienzyme-like activities from self-assembling peptides containing ATCUN copper-binding motifs. With the aid of the coordination interactions between the ATCUN motif and Cu(II) ions, these peptides could perform supramolecular self-assembly to form nanomaterials with biomimetic peroxidase, ascorbate oxidase and glutathione peroxidase activities. Moreover, these trienzyme-like effects can elevate oxidative stress levels and suppress the antioxidative capability of cancer cells, which synergistically induce the apoptosis of cancer cells. Because of the high biocompatibility, catalytic activities and drug encapsulation properties, this self-assembled peptide provides a biomimetic platform for the development of new nanocatalytic medicines for multimodal synergistic cancer therapies.

TGFβ2 mediates oxidative stress-induced epithelial-to-mesenchymal transition of bladder smooth muscle

Bladder outlet obstruction (BOO) is the primary clinical manifestation of benign prostatic hyperplasia, the most common urinary system disease in elderly men, and leads to associated lower urinary tract symptoms. Although BOO is reportedly associated with increased systemic oxidative stress (OS), the underlying mechanism remains unclear. The elucidation of this mechanism is the primary aim of this study. A Sprague-Dawley rat model of BOO was constructed and used for urodynamic monitoring. The bladder tissue of rats was collected and subjected to real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR), histological examination, and immunohistochemical staining. Through bioinformatics prediction, we found that transforming growth factor β2 (TGFβ2) expression was upregulated in rats with BOO compared with normal bladder tissue. In vitro analyses using primary bladder smooth muscle cells (BSMCs) revealed that hydrogen peroxide (H2O2) induced TGFβ2 expression. Moreover, H2O2 induced epithelial-to-mesenchymal transition (EMT) by reducing E-cadherin, an endothelial marker and CK-18, a cytokeratin maker, and increasing mesenchymal markers, including N-cadherin, vimentin, and α-smooth muscle actin (α-SMA) levels. The downregulation of TGFβ2 expression in BSMCs using siRNA technology alleviated H2O2-induced changes in EMT marker expression. The findings of the study indicate that TGFβ2 plays a crucial role in BOO by participating in OS-induced EMT in BSMCs.

High-performance self-cascade nanoreactors for combined ferroptosis, photothermal therapy, and starving therapy

Despite the great potential of starving therapy caused by nanoreactor based on glucose oxidase (GOX) in tumor therapy, efficiency and uncontrolled reaction rates in vivo lead to inevitable toxicity to normal tissues, which seriously hindering their clinical conversion. Herein, a cascade nanoreactor (GOX/Mn/MPDA) was constructed by coating mesoporous polydopamine nanoparticles (MPDA) with MnO2 shell and then depositing GOX into honeycomb-shaped manganese oxide nanostructures to achieve a combination of ferroptosis, photothermal therapy and starving therapy. Upon uptake of nanodrugs to cancer cells, the MnO2 shell would deplete glutathione (GSH) and produce Mn2+, while a large amount of H2O2 generated from the catalytic oxidation of glucose by GOX would accelerate the Fenton-like reaction mediated by Mn2+, producing high toxic •OH. More importantly, the cascade reaction between GOX and MnO2 would be further strengthened by localized hyperthermia caused by irradiated by near-infrared laser (NIR), inducing significant anti-tumor effects in vitro and in vivo. Regarding the effectiveness of tumor treatment in vivo, the tumor inhibition rate achieved an impressive 64.33%. This study provided a new strategy for anti-tumor therapeutic by designing a photothermal-enhanced cascade catalytic nanoreactor.

Biomedical applications of stimuli-responsive nanomaterials

Nanomaterials have aroused great interests in drug delivery due to their nanoscale structure, facile modifiability, and multifunctional physicochemical properties. Currently, stimuli-responsive nanomaterials that can respond to endogenous or exogenous stimulus display strong potentials in biomedical applications. In comparison with conventional nanomaterials, stimuli-responsive nanomaterials can improve therapeutic efficiency and reduce the toxicity of drugs toward normal tissues through specific targeting and on-demand drug release at pathological sites. In this review, we summarize the responsive mechanism of a variety of stimulus, including pH, redox, and enzymes within pathological microenvironment, as well as exogenous stimulus such as thermal effect, magnetic field, light, and ultrasound. After that, biomedical applications (e.g., drug delivery, imaging, and theranostics) of stimuli-responsive nanomaterials in a diverse array of common diseases, including cardiovascular diseases, cancer, neurological disorders, inflammation, and bacterial infection, are presented and discussed. Finally, the remaining challenges and outlooks of future research directions for the biomedical applications of stimuli-responsive nanomaterials are also discussed. We hope that this review can provide valuable guidance for developing stimuli-responsive nanomaterials and accelerate their biomedical applications in diseases diagnosis and treatment.

Manganese-induced Photothermal-Ferroptosis for Synergistic Tumor Therapy

Ferroptosis-related tumor therapy based on nanomedicines has recently gained significant attention. However, the therapeutic performance is still hindered by the tumor's physical barriers such as the fibrotic tumor matrix and elevated interstitial fluid pressure, as well as chemical barriers like glutathione (GSH) overabundance. These physicochemical barriers impede the bioavailability of nanomedicines and compromise the therapeutic efficacy of lipid reactive oxygen species (ROS). Thus, this study pioneers a manganese-mediated overcoming of physicochemical barriers in the tumor microenvironment using organosilica-based nanomedicine (MMONs), which bolsters the synergy of photothermal-ferroptosis treatment. The MMONs display commendable proficiency in overcoming tumor physical barriers, due to their MnO2-mediated shape-morphing and softness-transformation ability, which facilitates augmented cellular internalization, enhanced tumor accumulation, and superior drug penetration. Also, the MMONs possess excellent capability in chemical barrier overcoming, including MnO2-mediated dual GSH clearance and enhanced ROS generation, which facilitates ferroptosis and heat shock protein inhibition. Notably, the resulting integration of physical and chemical barrier overcoming leads to amplified photothermal-ferroptosis synergistic tumor therapy both in vitro and in vivo. Accordingly, the comparative proteomic analysis has identified promoted ferroptosis with a transient inhibitory response observed in the mitochondria. This research aims to improve treatment strategies to better fight the complex defenses of tumors.

Mg-gallate metal-organic framework-based sprayable hydrogel for continuously regulating oxidative stress microenvironment and promoting neurovascular network reconstruction in diabetic wounds

Chronic diabetic wounds are the most common complication for diabetic patients. Due to high oxidative stress levels affecting the entire healing process, treating diabetic wounds remains a challenge. Here, we present a strategy for continuously regulating oxidative stress microenvironment by the catalyst-like magnesium-gallate metal-organic framework (Mg-GA MOF) and developing sprayable hydrogel dressing with sodium alginate/chitosan quaternary ammonium salts to treat diabetic wounds. Chitosan quaternary ammonium salts with antibacterial properties can prevent bacterial infection. The continuous release of gallic acid (GA) effectively eliminates reactive oxygen species (ROS), reduces oxidative stress, and accelerates the polarization of M1-type macrophages to M2-type, shortening the transition between inflammation and proliferative phase and maintaining redox balance. Besides, magnesium ions adjuvant therapy promotes vascular regeneration and neuronal formation by activating the expression of vascular-associated genes. Sprayable hydrogel dressings with antibacterial, antioxidant, and inflammatory regulation rapidly repair diabetic wounds by promoting neurovascular network reconstruction and accelerating re-epithelialization and collagen deposition. This study confirms the feasibility of catalyst-like MOF-contained sprayable hydrogel to regulate the microenvironment continuously and provides guidance for developing the next generation of non-drug diabetes dressings.

Fangchinoline targets human renal cell carcinoma cells through modulation of apoptotic and non‑apoptotic cell deaths

The process of apoptosis is one of the essential processes involved in maintenance of homeostasis in the human body. It can aid to remove misfolded proteins or cellular organelles. This sequence is especially necessary in cancer cells. However, specifically targeting already apoptotic pathways can induce drug resistance in cancer cells and hence drugs can induce cell death by alternative mechanism. We investigated whether fangchinoline (FCN) can target renal carcinoma cells by inducing multiple cell death mechanisms. Both paraptosis, autophagy, and apoptosis were induced by FCN through stimulation of diverse molecular signaling pathways. FCN induced ROS production with GSH/GSSG imbalance, and ER stress. In addition, formation of autophagosome and autophagy related markers were stimulated by FCN. Moreover, FCN induced cell cycle arrest and PARP cleavage. Except for blocking protein synthesis, these three cell death pathways were found to be complementarily working together with each other. FCN also exhibited synergistic effects with paclitaxel in inducing programmed cell death in RCC cells. Our data indicates that FCN could induce apoptotic cell death and non-apoptotic cell death pathways and can be con-tribute to development of novel cancer prevention or therapy.

Targeting the redox vulnerability of acute myeloid leukaemia cells with a combination of auranofin and vitamin C

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by complex molecular and cytogenetic abnormalities. Pro-oxidant cellular redox status is a common hallmark of AML cells, providing a rationale for redox-based anticancer strategy. We previously discovered that auranofin (AUF), initially used for the treatment of rheumatoid arthritis and repositioned for its anticancer activity, can synergize with a pharmacological concentration of vitamin C (VC) against breast cancer cell line models. In this study, we observed that this drug combination synergistically and efficiently killed cells of leukaemic cell lines established from different myeloid subtypes. In addition to an induced elevation of reactive oxygen species and ATP depletion, a rapid dephosphorylation of 4E-BP1 and p70S6K, together with a strong inhibition of protein synthesis were early events in response to AUF/VC treatment, suggesting their implication in AUF/VC-induced cytotoxicity. Importantly, a study on 22 primary AML specimens from various AML subtypes showed that AUF/VC combinations at pharmacologically achievable concentrations were effective to eradicate primary leukaemic CD34+ cells from the majority of these samples, while being less toxic to normal cord blood CD34+ cells. Our findings indicate that targeting the redox vulnerability of AML with AUF/VC combinations could present a potential anti-AML therapeutic approach.

Targeting ROS in cancer: rationale and strategies

Reactive oxygen species (ROS) in biological systems are transient but essential molecules that are generated and eliminated by a complex set of delicately balanced molecular machineries. Disruption of redox homeostasis has been associated with various human diseases, especially cancer, in which increased ROS levels are thought to have a major role in tumour development and progression. As such, modulation of cellular redox status by targeting ROS and their regulatory machineries is considered a promising therapeutic strategy for cancer treatment. Recently, there has been major progress in this field, including the discovery of novel redox signalling pathways that affect the metabolism of tumour cells as well as immune cells in the tumour microenvironment, and the intriguing ROS regulation of biomolecular phase separation. Progress has also been made in exploring redox regulation in cancer stem cells, the role of ROS in determining cell fate and new anticancer agents that target ROS. This Review discusses these research developments and their implications for cancer therapy and drug discovery, as well as emerging concepts, paradoxes and future perspectives.

Ferroptosis in thyroid cancer: Potential mechanisms, effective therapeutic targets and predictive biomarker

Thyroid cancer is a prevalent endocrine malignancy whose global incidence has risen over the past several decades. Ferroptosis, a regulated form of cell death distinguished by the excessive buildup of iron-dependent lipid peroxidates, stands out from other programmed cell death pathways in terms of morphological and molecular characteristics. Increasing evidence suggests a close association between thyroid cancer and ferroptosis, that is, inducing ferroptosis effectively suppresses the proliferation of thyroid cancer cells and impede tumor advancement. Therefore, ferroptosis represents a promising therapeutic target for the clinical management of thyroid cancer in clinical settings. Alterations in ferroptosis-related genes hold potential for prognostic prediction in thyroid cancer. This review summarizes current studies on the role of ferroptosis in thyroid cancer, elucidating its mechanisms, therapeutic targets, and predictive biomarkers. The findings underscore the significance of ferroptosis in thyroid cancer and offer valuable insights into the development of innovative treatment strategies and accurate predictors for the thyroid cancer.

Strategies for the development of stimuli-responsive small molecule prodrugs for cancer treatment

Approved anticancer drugs typically face challenges due to their narrow therapeutic window, primarily because of high systemic toxicity and limited selectivity for tumors. Prodrugs are initially inactive drug molecules designed to undergo specific chemical modifications. These modifications render the drugs inactive until they encounter specific conditions or biomarkers in vivo, at which point they are converted into active drug molecules. This thoughtful design significantly improves the efficacy of anticancer drug delivery by enhancing tumor specificity and minimizing off-target effects. Recent advancements in prodrug design have focused on integrating these strategies with delivery systems like liposomes, micelles, and polymerosomes to further improve targeting and reduce side effects. This review outlines strategies for designing stimuli-responsive small molecule prodrugs focused on cancer treatment, emphasizing their chemical structures and the mechanisms controlling drug release. By providing a comprehensive overview, we aim to highlight the potential of these innovative approaches to revolutionize cancer therapy.

Intratumoral Microbiome: Foe or Friend in Reshaping the Tumor Microenvironment Landscape?

The role of the microbiome in cancer and its crosstalk with the tumor microenvironment (TME) has been extensively studied and characterized. An emerging field in the cancer microbiome research is the concept of the intratumoral microbiome, which refers to the microbiome residing within the tumor. This microbiome primarily originates from the local microbiome of the tumor-bearing tissue or from translocating microbiome from distant sites, such as the gut. Despite the increasing number of studies on intratumoral microbiome, it remains unclear whether it is a driver or a bystander of oncogenesis and tumor progression. This review aims to elucidate the intricate role of the intratumoral microbiome in tumor development by exploring its effects on reshaping the multileveled ecosystem in which tumors thrive, the TME. To dissect the complexity and the multitude of layers within the TME, we distinguish six specialized tumor microenvironments, namely, the immune, metabolic, hypoxic, acidic, mechanical and innervated microenvironments. Accordingly, we attempt to decipher the effects of the intratumoral microbiome on each specialized microenvironment and ultimately decode its tumor-promoting or tumor-suppressive impact. Additionally, we portray the intratumoral microbiome as an orchestrator in the tumor milieu, fine-tuning the responses in distinct, specialized microenvironments and remodeling the TME in a multileveled and multifaceted manner.

Smart nanocarriers for enzyme-activated prodrug therapy

Exogenous enzyme-activated prodrug therapy (EPT) is a potential cancer treatment strategy that delivers non-human enzymes into or on the surface of the cell and subsequently converts a non-toxic prodrug into an active cytotoxic substance at a specific location and time. The development of several pharmacological pairs based on EPT has been the focus of anticancer research for more than three decades. Numerous of these pharmacological pairs have progressed to clinical trials, and a few have achieved application in specific cancer therapies. The current review highlights the potential of enzyme-activated prodrug therapy as a promising anticancer treatment. Different microbial, plant, or viral enzymes and their corresponding prodrugs that advanced to clinical trials have been listed. Additionally, we discuss new trends in the field of enzyme-activated prodrug nanocarriers, including nanobubbles combined with ultrasound (NB/US), mesoscopic-sized polyion complex vesicles (PICsomes), nanoparticles, and extracellular vesicles (EVs), with special emphasis on smart stimuli-triggered drug release, hybrid nanocarriers, and the main application of nanotechnology in improving prodrugs.

Plasma-generated RONS in liquid transferred into cryo-microneedles patch for skin treatment of melanoma

Malignant melanoma is the most lethal form of skin cancer. As a promising anti-cancer agent, plasma-activated water (PAW) rich in reactive oxygen and nitrogen species (RONS) has shown significant potential for melanoma treatment. However, rapid decay of RONS and inefficient delivery of PAW in conventional injection methods limit its practical applications. To address this issue, here we report a new approach for the production of plasma-activated cryo-microneedles (PA-CMNs) patches using custom-designed plasma devices and processes. Our innovation is to incorporate PAW into the PA-CMNs that are fabricated using a fast cryogenic micro-molding method. It is demonstrated that PA-CMNs can be easily inserted into skin to release RONS and slow the decay of RONS thereby prolonging their bioactivity and effectiveness. The new insights into the effective melanoma treatment suggest that the rich mixture of RONS within PA-CMNs prepared by custom-developed hybrid plasma-assisted configuration induces both ferroptosis and apoptosis to selectively kill tumor cells. A significant inhibition of subcutaneous A375 melanoma growth was observed in PA-CMNs-treated tumor-bearing nude mice without any signs of systemic toxicity. The new approach based on PA-CMNs may potentially open new avenues for a broader range of disease treatments.

Design, synthesis, and biological evaluation of chalcone acetamide derivatives against triple negative breast cancer

Chalcones are chemical scaffolds found in natural products, particularly in plants, and are considered for structural diversity in medicinal chemistry for drug development. Herein, we designed and synthesised novel acetamide derivatives of chalcone, characterizing them using 1H NMR, 13C NMR, HRMS, and IR spectroscopic methods. These derivatives were then screened against human cancer cells for cytotoxicity using the SRB assay. Among the tested derivatives, 7g, with a pyrrolidine group, exhibited better cell growth inhibition activity against triple-negative breast cancer (TNBC) cells. Further assays, including SRB, colony formation, and fluorescent dye-based microscopic analysis, confirmed that 7g significantly inhibited MDA-MB-231 cell proliferation. Furthermore, 7g promoted apoptosis by upregulating cellular reactive oxygen species (ROS) levels and disrupting mitochondrial membrane potential (MMP). Elevated expression of pro-apoptotic proteins (Bax and caspase-3) and a higher Bax/Bcl-2 ratio with downregulation of anti-apoptotic (Bcl-2) protein levels were observed in TNBC cells. The above results suggest that 7g can promote cellular death through apoptotic mechanisms in TNBC cells.

Oxidative stress-related genes score predicts prognosis and immune cell infiltration landscape characterization in breast cancer

Background

The tumor microenvironment (TME) typically experiences oxidative stress (OS), marked by a high level of reactive oxygen species (ROS) that can impact tumor advancement and prognosis by modulating the behavior of tumor cells and various immune cells. Oxidative stress-related genes (OSRG) encompass a range of genes involved in ROS pathways, and their specific roles in breast cancer (BC) necessitate further investigation.

Methods

Univariate Cox analysis was performed on genes linked to the OS pathway in the Gene Set Enrichment Analysis (GSEA) database, leading to the identification of 29 significant OSRG in BC. OSRG was divided into three distinct clusters according to the expression and the OSRG score based on the differentially expressed genes (DEGs) was further calculated by principal component analysis (PCA). The correlation between OSRG score and BC clinical features, mutation characteristics, immune checkpoints and immune cell infiltration was analyzed. Establish a multiariable Cox regression model to predict OSRG score effects on clinical characteristics.

Results

Significant differences were observed in survival analysis, enriched pathways, and immune infiltration among the three OSRG clusters based on 29 genes. Gene clusters were identified through the final selected 395 DEGs, revealing three distinct OSRG expression patterns. An OSRG score model was constructed using DEGs, demonstrating a significant association between high OSRG score and poor prognosis. Significantly, immune checkpoint-related genes exhibited a notable upregulation in the high OSRG score cohort. Additionally, a positive correlation was observed between the OSRG score and tumor mutation burden (TMB) in BC. The OSRG score holds potential implications for clinical immunotherapy in BC patients, and a nomogram was constructed with robust predictive capability for evaluating patient prognosis.

Conclusions

This study elucidated the features of OSRG within BC TME and their possible prognostic significance, offering valuable insights for the development of more targeted immunotherapy approaches for individuals with BC.

Targeting Metabolic-Redox Nexus to Regulate Drug Resistance: From Mechanism to Tumor Therapy

Drug resistance is currently one of the biggest challenges in cancer treatment. With the deepening understanding of drug resistance, various mechanisms have been revealed, including metabolic reprogramming and alterations of redox balance. Notably, metabolic reprogramming mediates the survival of tumor cells in harsh environments, thereby promoting the development of drug resistance. In addition, the changes during metabolic pattern shift trigger reactive oxygen species (ROS) production, which in turn regulates cellular metabolism, DNA repair, cell death, and drug metabolism in direct or indirect ways to influence the sensitivity of tumors to therapies. Therefore, the intersection of metabolism and ROS profoundly affects tumor drug resistance, and clarifying the entangled mechanisms may be beneficial for developing drugs and treatment methods to thwart drug resistance. In this review, we will summarize the regulatory mechanism of redox and metabolism on tumor drug resistance and highlight recent therapeutic strategies targeting metabolic-redox circuits, including dietary interventions, novel chemosynthetic drugs, drug combination regimens, and novel drug delivery systems.

A highly potent bi-thiazole inhibitor of LOX rewires collagen architecture and enhances chemoresponse in triple-negative breast cancer

Lysyl oxidase (LOX) is upregulated in highly stiff aggressive tumors, correlating with metastasis, resistance, and worse survival; however, there are currently no potent, safe, and orally bioavailable small molecule LOX inhibitors to treat these aggressive desmoplastic solid tumors in clinics. Here we discovered bi-thiazole derivatives as potent LOX inhibitors by robust screening of drug-like molecules combined with cell/recombinant protein-based assays. Structure-activity relationship analysis identified a potent lead compound (LXG6403) with ∼3.5-fold specificity for LOX compared to LOXL2 while not inhibiting LOXL1 with a competitive, time- and concentration-dependent irreversible mode of inhibition. LXG6403 shows favorable pharmacokinetic properties, globally changes ECM/collagen architecture, and reduces tumor stiffness. This leads to better drug penetration, inhibits FAK signaling, and induces ROS/DNA damage, G1 arrest, and apoptosis in chemoresistant triple-negative breast cancer (TNBC) cell lines, PDX organoids, and in vivo. Overall, our potent and tolerable bi-thiazole LOX inhibitor enhances chemoresponse in TNBC, the deadliest breast cancer subtype.

A Pt nanoenzyme- and BODIPY-loaded nanoscale covalent organic framework for relieving intratumoural hypoxia to enhance photodynamic therapy

Herein, we report a composite COF material loaded with a Pt nanoenzyme and an organic photosensitizer BODIPY, synthesized via a stepwise post-synthetic modification. The obtained Pt@COF-BDP nanoparticles can efficiently and continuously convert H2O2 to O2, thereby increasing the efficiency of single-linear oxygen production and achieving efficient tumor inhibition.

Current progress in the regulation of endogenous molecules for enhanced chemodynamic therapy

Chemodynamic therapy (CDT) is a potential cancer treatment strategy, which relies on Fenton chemistry to transform hydrogen peroxide (H2O2) into highly cytotoxic reactive oxygen species (ROS) for tumor growth suppression. Although overproduced H2O2 in cancerous tissues makes CDT a feasible and specific tumor therapeutic modality, the treatment outcomes of traditional chemodynamic agents still fall short of expectations. Reprogramming cellular metabolism is one of the hallmarks of tumors, which not only supports unrestricted proliferative demands in cancer cells, but also mediates the resistance of tumor cells against many antitumor modalities. Recent discoveries have revealed that various cellular metabolites including H2O2, iron, lactate, glutathione, and lipids have distinct effects on CDT efficiency. In this perspective, we intend to provide a comprehensive summary of how different endogenous molecules impact Fenton chemistry for a deep understanding of mechanisms underlying endogenous regulation-enhanced CDT. Moreover, we point out the current challenges and offer our outlook on the future research directions in this field. We anticipate that exploring CDT through manipulating metabolism will yield significant advancements in tumor treatment.

Manipulating Redox Homeostasis of Cancer Stem Cells Overcome Chemotherapeutic Resistance through Photoactivatable Biomimetic Nanodiscs

Tumor heterogeneity remains a significant obstacle in cancer therapy due to diverse cells with varying treatment responses. Cancer stem-like cells (CSCs) contribute significantly to intratumor heterogeneity, characterized by high tumorigenicity and chemoresistance. CSCs reside in the depth of the tumor, possessing low reactive oxygen species (ROS) levels and robust antioxidant defense systems to maintain self-renewal and stemness. A nanotherapeutic strategy is developed using tumor-penetrating peptide iRGD-modified high-density lipoprotein (HDL)-mimetic nanodiscs (IPCND) that ingeniously loaded with pyropheophorbide-a (Ppa), bis (2-hydroxyethyl) disulfide (S-S), and camptothecin (CPT) by synthesizing two amphiphilic drug-conjugated sphingomyelin derivatives. Photoactivatable Ppa can generate massive ROS which as intracellular signaling molecules effectively shut down self-renewal and trigger differentiation of the CSCs, while S-S is utilized to deplete GSH and sustainably imbalance redox homeostasis by reducing ROS clearance. Simultaneously, the depletion of GSH is accompanied by the release of CPT, which leads to subsequent cell death. This dual strategy successfully disturbed the redox equilibrium of CSCs, prompting their differentiation and boosting the ability of CPT to kill CSCs upon laser irradiation. Additionally, it demonstrated a synergistic anti-cancer effect by concurrently eliminating therapeutically resistant CSCs and bulk tumor cells, effectively suppressing tumor growth in CSC-enriched heterogeneous colon tumor mouse models.

Bridging clinical radiotherapy and space radiation therapeutics through reactive oxygen species (ROS)-triggered delivery

This review explores the convergence of clinical radiotherapy and space radiation therapeutics, focusing on ionizing radiation (IR)-generated reactive oxygen species (ROS). IR, with high-energy particles, induces precise cellular damage, particularly in cancer treatments. The paper discusses parallels between clinical and space IR, highlighting unique characteristics of high-charge and energy particles in space and potential health risks for astronauts. Emphasizing the parallel occurrence of ROS generation in both clinical and space contexts, the review identifies ROS as a crucial factor with dual roles in cellular responses and potential disease initiation. The analysis covers ROS generation mechanisms, variations, and similarities in terrestrial and extraterrestrial environments leading to innovative ROS-responsive delivery systems adaptable for both clinical and space applications. The paper concludes by discussing applications of personalized ROS-triggered therapeutic approaches and discussing the challenges and prospects of implementing these strategies in clinical radiotherapy and extraterrestrial missions. Overall, it underscores the potential of ROS-targeted delivery for advancing therapeutic strategies in terrestrial clinical settings and space exploration, contributing to human health improvement on Earth and beyond.

Transcriptome of bone marrow-Derived stem cells reveals new inflammatory mediators related to increased survival in patients with multiple myeloma

Although multiple myeloma (MM) is a neoplasm that leads affected individuals to death, little is known about why some patients survive much longer than others. In this context, we investigated the transcriptomic profile of bone marrow hematopoietic stem cells obtained from MM patients and compared the clinical outcomes of death and survival six months after bone marrow transplantation. The leukapheresis products of 39 patients with MM eligible for autologous transplantation were collected and analyzed. After extraction, the RNA was analyzed using the GeneChip Human Exon 1.0 Array method. The transcriptome profile was analyzed in silico, and the differentially expressed signaling pathways of interest were validated. The results showed a difference in the expression of inflammation-related genes, immune response processes, and the oxidative stress pathway. The in silico study also pointed out the involvement of the NFκB transcription factor in the possible modulation of these genes. We chose to validate molecules participating in these processes, including the cytokines TNF-α, IFN-γ, and TGF-β1; in addition, we measured the levels of oxidative stress mediators (pro-oxidant profile and the total antioxidant capacity). TNF-α levels were significantly reduced in patients who died and were over 50 years old at diagnosis, as well as in patients with plasmacytoma. Increased TNF-α was detected in patients with very high levels of β2-microglobulin. IFN-γ reduction was observed in patients with a complete response to treatment compared to those with a very good response. Patients with plasmacytoma who died also had an increased pro-oxidant profile. These data show the profile of inflammatory response markers that are altered in patients with MM who die quickly and serve as a basis for the development of future studies of markers to predict better survival in this disease.

Exploration of individual colorectal cancer cell responses to H2O2 eustress using hopping probe scanning ion conductance microscopy

Colorectal cancer (CRC), a widespread malignancy, is closely associated with tumor microenvironmental hydrogen peroxide (H2O2) levels. Some clinical trials targeting H2O2 for cancer treatment have revealed its paradoxical role as a promoter of cancer progression. Investigating the dynamics of cancer cell H2O2 eustress at the single-cell level is crucial. In this study, non-contact hopping probe mode scanning ion conductance microscopy (HPICM) with high-sensitive Pt-functionalized nanoelectrodes was employed to measure dynamic extracellular to intracellular H2O2 gradients in individual colorectal cancer Caco-2 cells. We explored the relationship between cellular mechanical properties and H2O2 gradients. Exposure to 0.1 or 1 mmol/L H2O2 eustress increased the extracellular to intracellular H2O2 gradient from 0.3 to 1.91 or 3.04, respectively. Notably, cellular F-actin-dependent stiffness increased at 0.1 mmol/L but decreased at 1 mmol/L H2O2 eustress. This H2O2-induced stiffness modulated AKT activation positively and glutathione peroxidase 2 (GPX2) expression negatively. Our findings unveil the failure of some H2O2-targeted therapies due to their ineffectiveness in generating H2O2, which instead acts eustress to promote cancer cell survival. This research also reveals the complex interplay between physical properties and biochemical signaling in cancer cells' antioxidant defense, illuminating the exploitation of H2O2 eustress for survival at the single-cell level. Inhibiting GPX and/or catalase (CAT) enhances the cytotoxic activity of H2O2 eustress against CRC cells, which holds significant promise for developing innovative therapies targeting cancer and other H2O2-related inflammatory diseases.

The Cancer Antioxidant Regulation System in Therapeutic Resistance

Antioxidants play a pivotal role in neutralizing reactive oxygen species (ROS), which are known to induce oxidative stress. In the context of cancer development, cancer cells adeptly maintain elevated levels of both ROS and antioxidants through a process termed "redox reprogramming". This balance optimizes the proliferative influence of ROS while simultaneously reducing the potential for ROS to cause damage to the cell. In some cases, the adapted antioxidant machinery can hamper the efficacy of treatments for neoplastic diseases, representing a significant facet of the resistance mechanisms observed in cancer therapy. In this review, we outline the contribution of antioxidant systems to therapeutic resistance. We detail the fundamental constituents of these systems, encompassing the central regulatory mechanisms involving transcription factors (of particular importance is the KEAP1/NRF2 signaling axis), the molecular effectors of antioxidants, and the auxiliary systems responsible for NADPH generation. Furthermore, we present recent clinical trials based on targeted antioxidant systems for the treatment of cancer, assessing the potential as well as challenges of this strategy in cancer therapy. Additionally, we summarize the pressing issues in the field, with the aim of illuminating a path toward the emergence of novel anticancer therapeutic approaches by orchestrating redox signaling.