Free radical stress in chronic lymphocytic leukemia cells and its role in cellular sensitivity to ROS-generating anticancer agents

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.

Novel Spirocyclic Dimer, SpiD3, Targets Chronic Lymphocytic Leukemia Survival Pathways with Potent Preclinical Effects

Chronic lymphocytic leukemia (CLL) cell survival and growth is fueled by the induction of B-cell receptor (BCR) signaling within the tumor microenvironment (TME) driving activation of NFκB signaling and the unfolded protein response (UPR). Malignant cells have higher basal levels of UPR posing a unique therapeutic window to combat CLL cell growth using pharmacologic agents that induce accumulation of misfolded proteins. Frontline CLL therapeutics that directly target BCR signaling such as Bruton tyrosine kinase (BTK) inhibitors (e.g., ibrutinib) have enhanced patient survival. However, resistance mechanisms wherein tumor cells bypass BTK inhibition through acquired BTK mutations, and/or activation of alternative survival mechanisms have rendered ibrutinib ineffective, imposing the need for novel therapeutics. We evaluated SpiD3, a novel spirocyclic dimer, in CLL cell lines, patient-derived CLL samples, ibrutinib-resistant CLL cells, and in the Eµ-TCL1 mouse model. Our integrated multi-omics and functional analyses revealed BCR signaling, NFκB signaling, and endoplasmic reticulum stress among the top pathways modulated by SpiD3. This was accompanied by marked upregulation of the UPR and inhibition of global protein synthesis in CLL cell lines and patient-derived CLL cells. In ibrutinib-resistant CLL cells, SpiD3 retained its antileukemic effects, mirrored in reduced activation of key proliferative pathways (e.g., PRAS, ERK, MYC). Translationally, we observed reduced tumor burden in SpiD3-treated Eµ-TCL1 mice. Our findings reveal that SpiD3 exploits critical vulnerabilities in CLL cells including NFκB signaling and the UPR, culminating in profound antitumor properties independent of TME stimuli.

SIGNIFICANCE

SpiD3 demonstrates cytotoxicity in CLL partially through inhibition of NFκB signaling independent of tumor-supportive stimuli. By inducing the accumulation of unfolded proteins, SpiD3 activates the UPR and hinders protein synthesis in CLL cells. Overall, SpiD3 exploits critical CLL vulnerabilities (i.e., the NFκB pathway and UPR) highlighting its use in drug-resistant CLL.

A Sequentially Activated Probe for Imaging of Superoxide Anion and Peroxynitrite in PC12 Cells under Oxidative Stress

Superoxide anion (O2·-) and peroxynitrite (ONOO-), two important oxidants under oxidative stress, coexist in complex cell and organism systems, playing crucial roles in various physiological and pathological processes, particularly in neurodegenerative diseases. Despite the absence of robust molecular tools capable of simultaneously visualizing O2·- and ONOO- in biosystems, the relationship between these two species remains understudied. Herein, we present sequentially activated fluorescent probe, DHX-SP, which exhibits exceptional selectivity and sensitivity toward O2·- and ONOO-. This probe enables precise imaging of these species in living PC12 cells under oxidative stress conditions using distinct fluorescence signal combinations. Furthermore, the probe DHX-SP has the ability to visualize changes in O2·- and ONOO- levels during ferroptosis of PC12 cells and in the Parkinson's disease model. These findings establish a connection between the crosstalk of the phosphorus group of O2·- and ONOO- in PC12 cells under oxidative stress.

Comprehensive analysis of CYBB as a prognostic marker and therapeutic target in glioma: A bioinformatics approach

Background

In the central nervous system, glioma is the most common malignant tumor, and patients have a poor prognosis. Identification of novel marker genes and establishment of prognostic models are important for early diagnosis and prognosis determination.

Methods

Download glioma data from the CGGA and TCG databases. Application of bioinformatics to analyze the impact of CYBB on the clinicopathological characteristics, immunological features and prognosis of gliomas. Using single-cell sequencing data from 7 glioblastoma patients in the CGGA database, the role of CYBB in the tumor microenvironment was analyzed. In addition, a prognostic model was constructed based on CYBB high and low differentially expressed genes and mitochondrial genes.

Results

The expression of CYBB is closely related to various clinical features, immune cell infiltration level, immune checkpoint and survival time of patients. A 10-gene prediction model was constructed based on the differentially expressed genes of low and high CYBB and mitochondria-related genes. Glioma patients with higher risk scores had significantly lower survival probabilities. Receiver operating characteristic curves and nomograms were plotted over time to show the predictive accuracy and predictive value of the 10-gene prognostic model.

Conclusions

Our study shows that CYBB is strongly correlated with clinical characteristics features and prognosis of glioma patients, and can be used as a potential therapeutic target. Prognostic models based on CYBB and mitochondrial genes have good performance in predicting prognosis of glioma patients.

Potential New Therapies "ROS-Based" in CLL: An Innovative Paradigm in the Induction of Tumor Cell Apoptosis

Chronic lymphocytic leukemia, in spite of recent advancements, is still an incurable disease; the majority of patients eventually acquire resistance to treatment through relapses. In all subtypes of chronic lymphocytic leukemia, the disruption of normal B-cell homeostasis is thought to be mostly caused by the absence of apoptosis. Consequently, apoptosis induction is crucial to the management of this illness. Damaged biological components can accumulate as a result of the oxidation of intracellular lipids, proteins, and DNA by reactive oxygen species. It is possible that cancer cells are more susceptible to apoptosis because of their increased production of reactive oxygen species. An excess of reactive oxygen species can lead to oxidative stress, which can harm biological elements like DNA and trigger apoptotic pathways that cause planned cell death. In order to upset the balance of oxidative stress in cells, recent therapeutic treatments in chronic lymphocytic leukemia have focused on either producing reactive oxygen species or inhibiting it. Examples include targets created in the field of nanomedicine, natural extracts and nutraceuticals, tailored therapy using biomarkers, and metabolic targets. Current developments in the complex connection between apoptosis, particularly ferroptosis and its involvement in epigenomics and alterations, have created a new paradigm.

New Derivatives of 1-(3-Methyl-1-Benzofuran-2-yl)Ethan-1-one: Synthesis and Preliminary Studies of Biological Activity

A set of nine derivatives, including five brominated compounds, was synthesized and the structures of these novel compounds were confirmed using 1H and 13C NMR as well as ESI MS spectra. These compounds were tested on four different cancer cell lines, chronic myelogenous leukemia (K562), prostate cancer (PC3), colon cancer (SW620), human kidney cancer (Caki 1), and on healthy human keratocytes (HaCaT). MTT results reveal that two newly developed derivatives (6 and 8) exhibit selective action towards K562 cells and no toxic effect in HaCat cells. The biological activity of these two most promising compounds was evaluated by trypan blue assay, reactive oxygen species generation, and IL-6 secretion. To investigate the proapoptotic activity of selected compounds, the two following types of tests were performed: Annexin V Apoptosis Detection Kit I and Caspase-Glo 3/7 assay. The studies of the mechanism showed that both compounds have pro-oxidative effects and increase reactive oxygen species in cancer cells, especially at 12 h incubation. Through the Caspase-Glo 3/7 assay, the proapoptotic properties of both compounds were confirmed. The Annexin V-FITC test revealed that compounds 6 and 8 induce apoptosis in K562 cells. Both compounds inhibit the release of proinflammatory interleukin 6 (IL-6) in K562 cells. Additionally, all compounds were screened for their antibacterial activities using standard and clinical strains. Within the studied group, compound 7 showed moderate activity towards Gram-positive strains in antimicrobial studies, with MIC values ranging from 16 to 64 µg/mL.

Site-specific controlled-release nanoparticles for immune reprogramming via dual metabolic inhibition against triple-negative breast cancer

Metabolic heterogeneity and the tumor immunosuppressive microenvironment (TIME) of triple-negative breast cancer (TNBC) hinder therapeutic effectiveness. Although emerging metabolic therapy and immunotherapy show promise, they are limited by off-target effects and immune escape. Here, a redox-activatable, sequentially-releasing nanoparticle (AMANC@M) for tumor-targeted delivery of anticancer agents and CRISPR/Cas9 has been developed. AMANC@M can reverse the TIME through dual metabolic inhibition, thereby enhancing TNBC therapy. AMANC@M demonstrates excellent biosafety and targets tumors precisely through biomimetic hybrid membrane-mediated homologous homing and the enhanced permeability and retention (EPR) effect. Once internalized into tumor cells, the CRISPR/Cas9 system ("energy nanolock") is released through glutathione (GSH) cleavage and effectively knocks down the expression of lactate dehydrogenase A (LDHA) to suppress glycolysis. After peeling off of the gene editing shell, a newly synthesized targeted drug, CPI-Z2 ("nutrihijacker" and "energy nanolock"), is released in a controlled manner to block the mitochondrial tricarboxylic acid (TCA) cycle. Nitric oxide (NO) produced from loaded L-arginine enhances the efficiency of CPI-Z2 and reduces drug resistance. Combined with NO therapy, both blockades of nutrients and energy production transform the hypoxia and acidic TIME into an immunocompetent tumor microenvironment (TME) for tumor elimination. Furthermore, AMANC@M offers capabilities for photothermal (PT) therapy and provides clear imaging through PT, photoacoustic (PA), or computed tomography (CT) signals in tumor tissue. Thus, this study provides a new and promising sequentially stimuli-responsive targeting strategy for nanoparticle development, making it a potential treatment candidate for TNBC and other tumors.

The Role of the Microenvironment and Cell Adhesion Molecules in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy whose progression largely depends on the lymph node and bone marrow microenvironment. Indeed, CLL cells actively proliferate in specific regions of these anatomical compartments, known as proliferation centers, while being quiescent in the blood stream. Hence, CLL cell adhesion and migration into these protective niches are critical for CLL pathophysiology. CLL cells are lodged in their microenvironment through a series of molecular interactions that are mediated by cellular adhesion molecules and their counter receptors. The importance of these adhesion molecules in the clinic is demonstrated by the correlation between the expression levels of some of them, in particular CD49d, and the prognostic likelihood. Furthermore, novel therapeutic agents, such as ibrutinib, impair the functions of these adhesion molecules, leading to an egress of CLL cells from the lymph nodes and bone marrow into the circulation together with an inhibition of homing into these survival niches, thereby preventing disease progression. Several adhesion molecules have been shown to participate in CLL adhesion and migration. Their importance also stems from the observation that they are involved in promoting, directly or indirectly, survival signals that sustain CLL proliferation and limit the efficacy of standard and novel chemotherapeutic drugs, a process known as cell adhesion-mediated drug resistance. In this respect, many studies have elucidated the molecular mechanisms underlying cell adhesion-mediated drug resistance, which have highlighted different signaling pathways that may represent potential therapeutic targets. Here, we review the role of the microenvironment and the adhesion molecules that have been shown to be important in CLL and their impact on transendothelial migration and cell-mediated drug resistance. We also discuss how novel therapeutic compounds modulate the function of this important class of molecules.

Platelet-derived microparticles provoke chronic lymphocytic leukemia malignancy through metabolic reprogramming

Background

It is well established that inflammation and platelets promote multiple processes of cancer malignancy. Recently, platelets have received attention for their role in carcinogenesis through the production of microvesicles or platelet-derived microparticles (PMPs), which transfer their biological content to cancer cells. We have previously characterized a new subpopulation of these microparticles (termed mito-microparticles), which package functional mitochondria. The potential of mitochondria transfer to cancer cells is particularly impactful as many aspects of mitochondrial biology (i.e., cell growth, apoptosis inhibition, and drug resistance) coincide with cancer hallmarks and disease progression. These metabolic aspects are particularly notable in chronic lymphocytic leukemia (CLL), which is characterized by a relentless accumulation of proliferating, immunologically dysfunctional, mature B-lymphocytes that fail to undergo apoptosis. The present study aimed to investigate the role of PMPs on CLL metabolic plasticity leading to cancer cell phenotypic changes.

Methods

CLL cell lines were co-incubated with different concentrations of human PMPs, and their impact on cell proliferation, mitochondrial DNA copy number, OCR level, ATP production, and ROS content was evaluated. Essential genes involved in metabolic-reprogramming were identified using the bioinformatics tools, examined between patients with early and advanced CLL stages, and then validated in PMP-recipient CLLs. Finally, the impact of the induced metabolic reprogramming on CLLs' growth, survival, mobility, and invasiveness was tested against anti-cancer drugs Cytarabine, Venetoclax, and Plumbagin.

Results

The data demonstrated the potency of PMPs in inducing tumoral growth and invasiveness in CLLs through mitochondrial internalization and OXPHOS stimulation which was in line with metabolic shift reported in CLL patients from early to advanced stages. This metabolic rewiring also improved CLL cells' resistance to Cytarabine, Venetoclax, and Plumbagin chemo drugs.

Conclusion

Altogether, these findings depict a new platelet-mediated pathway of cancer pathogenesis. We also highlight the impact of PMPs in CLL metabolic reprogramming and disease progression.

Perhexiline: Old Drug, New Tricks? A Summary of Its Anti-Cancer Effects

Cancer metabolic plasticity, including changes in fatty acid metabolism utilisation, is now widely appreciated as a key driver for cancer cell growth, survival and malignancy. Hence, cancer metabolic pathways have been the focus of much recent drug development. Perhexiline is a prophylactic antianginal drug known to act by inhibiting carnitine palmitoyltransferase 1 (CPT1) and 2 (CPT2), mitochondrial enzymes critical for fatty acid metabolism. In this review, we discuss the growing evidence that perhexiline has potent anti-cancer properties when tested as a monotherapy or in combination with traditional chemotherapeutics. We review the CPT1/2 dependent and independent mechanisms of its anti-cancer activities. Finally, we speculate on the clinical feasibility and utility of repurposing perhexiline as an anti-cancer agent, its limitations including known side effects and its potential added benefit of limiting cardiotoxicity induced by other chemotherapeutics.

Malignant growth of arsenic-transformed cells depends on activated Akt induced by reactive oxygen species

Arsenic is an identified carcinogen for humans.In this study, chronic exposure of human hepatocyte L-02 to low-doses of inorganic arsenic caused cell malignant proliferation. Meanwhile, compared with normal L-02 cells, arsenic-transformed malignant cells, L-02-As displayed more ROS and significantly higher Cyclin D1 expression as well as aerobic glycolysis. Moreover, Akt activation is followed by the upregulation of Cyclin D1 and HK2 expression in L-02-As cells, since inhibition of Akt activity by Ly294002 attenuated the colony formation in soft agar and decreased the levels of Cyclin D1 and HK2. In addition, scavenging of ROS by NAC resulted in a decreased expression of phospho-Akt, HK2 and Cyclin D1, and attenuates the ability of anchorage-independent growth ofL-02-As cells, suggested that ROS mediated the Akt activation in L-02-As cells. In summary, our results demonstrated that ROS contributes to the malignant phenotype of arsenic-transformed human hepatocyte L-02-As via the activation of Akt pathway.

Mitochondria-Related Transcriptome Characterization Associated with the Immune Microenvironment, Therapeutic Response and Survival Prediction in Pancreatic Cancer

(1) Background: Pancreatic cancer (PC) is one of the most lethal tumors. Mitochondrial dysfunction has been reported to be involved in cancer development; however, its role in PC has remained unclear. (2) Methods: The differentially expressed NMGs were selected between PC and normal pancreatic tissue. The NMG-related prognostic signature was established by LASSO regression. A nomogram was developed based on the 12-gene signature combined with other significant pathological features. An extensive analysis of the 12 critical NMGs was performed in multiple dimensions. The expression of some key genes was verified in our external cohort. (3) Results: Mitochondria-related transcriptome features was obviously altered in PC compared with normal pancreas tissue. The 12-NMG signature showed good performance in predicting prognosis in various cohorts. The high- and low-risk groups exhibited notable diversity in gene mutation characteristics, biological characteristics, chemotherapy response, and the tumor immune microenvironment. Critical gene expression was demonstrated in our cohort at the mRNA and protein levels and in organelle localization. (4) Conclusions: Our study analyzed the mitochondrial molecular characterization of PC, proving the crucial role of NMGs in PC development. The established NMG signature helps classify patient subtypes in terms of prognosis prediction, treatment response, immunological features, and biological function, providing a potential therapeutic strategy targeting mitochondrial transcriptome characterization.

Ruthenium Complex HB324 Induces Apoptosis via Mitochondrial Pathway with an Upregulation of Harakiri and Overcomes Cisplatin Resistance in Neuroblastoma Cells In Vitro

Ruthenium(II) complexes with N-heterocyclic carbene (NHC) ligands have recently attracted attention as novel chemotherapeutic agents. The complex HB324 was intensively studied as an apoptosis-inducing compound in resistant cell lines. HB324 induced apoptosis via mitochondrial pathways. Of particular interest is the upregulation of the Harakiri resistance protein, which inhibits the anti-apoptotic and death repressor proteins Bcl-2 (B-cell lymphoma 2) and BCL-xL (B-cell lymphoma-extra large). Moreover, HB324 showed synergistic activity with various established anticancer drugs and overcame resistance in several cell lines, such as neuroblastoma cells. In conclusion, HB324 showed promising potential as a novel anticancer agent in vitro, suggesting further investigations on this and other preclinical ruthenium drug candidates.

Molecular mechanisms behind ROS regulation in cancer: A balancing act between augmented tumorigenesis and cell apoptosis

ROS include hydroxyl radicals (HO^.), superoxide (O₂^..), and hydrogen peroxide (H₂O₂). ROS are typically produced under physiological conditions and play crucial roles in living organisms. It is known that ROS, which are created spontaneously by cells through aerobic metabolism in mitochondria, can have either a beneficial or detrimental influence on biological systems. Moderate levels of ROS can cause oxidative damage to proteins, DNA and lipids, which can aid in the pathogenesis of many disorders, including cancer. However, excessive concentrations of ROS can initiate programmed cell death in cancer. Presently, a variety of chemotherapeutic drugs and herbal agents are being investigated to induce ROS-mediated cell death in cancer. Therefore, preserving ROS homeostasis is essential for ensuring normal cell development and survival. On account of a significant association of ROS levels at various concentrations with carcinogenesis in a number of malignancies, further studies are needed to determine the underlying molecular mechanisms and develop the possibilities for intervening in these processes.

The rs1001179 SNP and CpG methylation regulate catalase expression in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is an incurable disease characterized by an extremely variable clinical course. We have recently shown that high catalase (CAT) expression identifies patients with an aggressive clinical course. Elucidating mechanisms regulating CAT expression in CLL is preeminent to understand disease mechanisms and develop strategies for improving its clinical management. In this study, we investigated the role of the CAT promoter rs1001179 single nucleotide polymorphism (SNP) and of the CpG Island II methylation encompassing this SNP in the regulation of CAT expression in CLL. Leukemic cells harboring the rs1001179 SNP T allele exhibited a significantly higher CAT expression compared with cells bearing the CC genotype. CAT promoter harboring the T -but not C- allele was accessible to ETS-1 and GR-β transcription factors. Moreover, CLL cells exhibited lower methylation levels than normal B cells, in line with the higher CAT mRNA and protein expressed by CLL in comparison with normal B cells. Methylation levels at specific CpG sites negatively correlated with CAT levels in CLL cells. Inhibition of methyltransferase activity induced a significant increase in CAT levels, thus functionally validating the role of CpG methylation in regulating CAT expression in CLL. Finally, the CT/TT genotypes were associated with lower methylation and higher CAT levels, suggesting that the rs1001179 T allele and CpG methylation may interact in regulating CAT expression in CLL. This study identifies genetic and epigenetic mechanisms underlying differential expression of CAT, which could be of crucial relevance for the development of therapies targeting redox regulatory pathways in CLL.

Triphlorethol-A attenuates U251 human glioma cancer cell proliferation and ameliorates apoptosis through JAK2/STAT3 and p38 MAPK/ERK signaling pathways

Glioma is the foremost recurrent type of brain tumor in humans; in particular, glioblastoma (GBM) is the main form of brain tumor (GBM) that is highly proliferative and impervious to apoptosis. Triphlorethol-A (TA), a phlorotannin isolated from Ecklonia cava, exhibited cytoprotective, antioxidant, and anticancer properties. However, the exact molecular action of TA in the U251 human GBM cells remains unknown. This may be the first report on the antiproliferative and apoptotic mechanisms of TA on GBM. The cytotoxicity, intracellular reactive oxygen species (ROS), matrix metalloproteinase (MMP), and cell apoptosis activity of TA have been evaluated by the MTT assay and by DCFH-DA, Rh-123, AO/EB, and western blot analysis. The results obtained showed that TA abridged the viability of U251 cells, while MMP increased apoptosis by increasing the ROS levels in a time-dependent manner. The results showed that a reduction in U251 cell proliferation was associated with the regulation of JAK2/STAT3 and p38 MAPK/ERK signaling pathways. TA was found to suppress pJAK, pSTAT3, p38 MAPK, and pERK phosphorylation, thereby causing Bax/Bcl-2 imbalance, activating the caspase cascade and cytochrome c, and inducing apoptosis. Our findings showed that the suppression of JAK2/STAT3 and p38 MAPK/ERK signaling by TA results in cell growth arrest and stimulation of apoptosis in GBM cells. These studies justify the protective remedy of TA against GBM.

Simultaneous fluorescence imaging of Golgi O2•- and Golgi H2O2 in mice with hypertension

Hypertensive cardiovascular disease is a persistent threat to public health. Elucidating the pathogenesis of hypertension is expected to provide more highly targeted therapies for patients. To date, reactive oxygen species (ROS) induced endothelial nitric oxide synthase (eNOS) uncoupling are generally considered to be common phenomena in hypertension. However, the critical factor contribute to persistent eNOS uncoupling remains poorly understood. Herein, we established a fluorescence probe, Gol_ROS, for the multicolored and simultaneous detection of Golgi O₂^•- and H₂O₂ in situ. We successfully detected increases in Golgi ROS levels in hypertensive mice and evaluated the pharmaceutical effects of various antihypertensive drugs. More importantly, we identified the ROS post-transcriptional modification sites on dihydrofolate reductase (DHFR). Altogether, we propose a novel therapeutic target for hypertension, which will promote the development of new antihypertensive drugs, and also developed an ideal fluorescence probe to study in situ Golgi O₂^•- and H₂O₂ changes in various biochemical processes.

A Redoxable Mn Porphyrin, MnTnBuOE-2-PyP5+, Synergizes with Carboplatin in Treatment of Chemoresistant Ovarian Cell Line

We have employed a redox-active MnP (MnTnBuOE-2-PyP⁵⁺, Mn(III) meso-tetrakis (N-n-butoxyethylpyridinium-2-yl) porphyrin) frequently identified as superoxide dismutase mimic or BMX-001, to explore the redox status of normal ovarian cell in relation to two ovarian cancer cell lines: OV90 human serous ovarian cancer cell and chemotherapy-resistant OV90 cell (OVCD). We identified that OVCD cells are under oxidative stress due to high hydrogen peroxide (H₂O₂) levels and low glutathione peroxidase and thioredoxin 1. Furthermore, OVCD cells have increased glycolysis activity and mitochondrial respiration when compared to immortalized ovarian cells (hTER7) and parental cancer cells (OV90). Our goal was to study how ovarian cell growth depends upon the redox state of the cell; hence, we used MnP (BMX-001), a redox-active MnSOD mimetic, as a molecular tool to alter ovarian cancer redox state. Interestingly, OVCD cells preferentially uptake MnP relative to OV90 cells which led to increased inhibition of cell growth, glycolytic activity, OXPHOS, and ATP, in OVCD cells. These effects were further increased when MnP was combined with carboplatin. The effects were discussed with regard to the elevation in H₂O₂ levels, increased oxidative stress, and reduced Nrf2 levels and its downstream targets when cells were exposed to either MnP or MnP/carboplatin. It is significant to emphasize that MnP protects normal ovarian cell line, hTER7, against carboplatin toxicity. Our data demonstrate that the addition of MnP-based redox-active drugs may be used (via increasing excessively the oxidative stress of serous ovarian cancer cells) to improve cancer patients' chemotherapy outcomes, which develop resistance to platinum-based drugs.

2-Methoxyestradiol combined with ascorbic acid facilitates the apoptosis of chronic myeloid leukemia cells via the microRNA-223/Fms-like tyrosine kinase 3/phosphatidylinositol-3 kinase/protein kinase B axis

Chronic myeloid leukemia (CML) is a malignant myeloproliferative tumor. 2-Methoxyestradiol (2-ME) is an endogenous estrogen metabolite that shows efficacy in human malignancies. Ascorbic acid (AA) possesses antioxidant activity. This study explored the mechanism of 2-ME combined with AA in the apoptosis of CML cells. Firstly, human CML cell lines were treated with 2-ME and AA. The cell viability, apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were detected. miR-223 expression in CML cells was detected. In addition, CML cells were transfected with miR-223 inhibitor. The binding relationship between miR-223 and FLT3 was verified. Subsequently, the FLT3 was overexpressed or silenced for the function rescue experiment to confirm the role of FLT3 in CML cell apoptosis. The expression levels of key factors of the PI3K/AKT pathway were detected. Finally, xenograft nude mouse models were established for in vivo verification. 2-ME + AA treatment inhibited CML cell viability and promoted apoptosis, elevated ROS content, and reduced MMP. 2-ME + AA treatment promoted miR-223 expression in CML cells. miR-223 targeted FLT3. Moreover, miR-223 inhibitor or FLT3 overexpression partially annulled the effect of 2-ME + AA on CML cells. 2-ME + AA inhibited the PI3K/AKT pathway via the miR-223/FLT3 axis. Furthermore, 2-ME + AA suppressed CML xenograft growth in mice. Collectively, 2-ME + AA promoted miR-223 expression and suppressed FLT3 and the PI3K/AKT pathway, thereby facilitating the apoptosis of CML cells and inhibiting CML xenograft growth in mice.

Chemotherapy induces plasmatic antioxidant changes in pediatric patients with acute lymphoid leukemia B that correlate to disease prognosis

Pediatric acute lymphoid leukemias (ALL) is the most common childhood cancer, and cytotoxic chemotherapy remains the primary treatment option. Chemotherapic drugs act by oxidative stress generation, but their clinical meaning is poorly understood. During the chemotherapy schedule, this study evaluated the antioxidant profile of peripheral blood samples from 34 patients diagnosed with type B-cell ALL (B-ALL). Peripheral blood samples were collected at diagnosis (D0) and during the induction, consolidation, and maintenance phases. The plasma total antioxidant capacity (TRAP) was determined using the high-sensitivity chemiluminescence technique. Antioxidant levels were higher on D0 compared to day 7 after treatment starting (D7) in the induction phase (28.68–1194.71 μM Trolox, p = 0.0178) and in the high-risk group (age > ten years and/or with white blood cell counts and/or > 50,000 white blood cells/m3 at diagnosis) concerning low-risk patients (253.79–1194.71 μM Trolox, p = 0.0314). Reduced TRAP was also detected in patients who died compared to those who survived (392.42–1194.71 μM Trolox, p = 0.0278). Patients under consolidation (56.14–352.05 μM Trolox, p=<0.0001) and maintenance (30.48–672.99 μM Trolox, p=<0.0001) showed a significant reduction in TRAP levels compared to those from the induction phase (28.68–1390.26 μM Trolox), reaching levels similar to cured patients out of treatment (64.82–437.82 μM Trolox). These findings suggest that the variation of the total antioxidant capacity in B-ALL during chemotherapy is a parameter that correlates to some predictors of disease prognosis.

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ALL is the most common neoplasia in children.

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Oxidative stress is reported in ALL patients, but the relationship between antioxidants and disease profile is unknown.

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Changes in blood antioxidants during chemotherapy correlates to survival and risk stratification in childhood ALL.

A Mitochondrial Dysfunction and Oxidative Stress Pathway-Based Prognostic Signature for Clear Cell Renal Cell Carcinoma

Mitochondria not only are the main source of ATP synthesis but also regulate cellular redox balance and calcium homeostasis. Its dysfunction can lead to a variety of diseases and promote cancer and metastasis. In this study, we aimed to explore the molecular characteristics and prognostic significance of mitochondrial genes (MTGs) related to oxidative stress in clear cell renal cell carcinoma (ccRCC). A total of 75 differentially expressed MTGs were analyzed from The Cancer Genome Atlas (TCGA) database, including 46 upregulated and 29 downregulated MTGs. Further analysis screened 6 prognostic-related MTGs (ACAD11, ACADSB, BID, PYCR1, SLC25A27, and STAR) and was used to develop a signature. Kaplan-Meier survival and receiver operating characteristic (ROC) curve analyses showed that the signature could accurately distinguish patients with poor prognosis and had good individual risk stratification and prognostic potential. Stratified analysis based on different clinical variables indicated that the signature could be used to evaluate tumor progression in ccRCC. Moreover, we found that there were significant differences in immune cell infiltration between the low- and high-risk groups based on the signature and that ccRCC patients in the low-risk group responded better to immunotherapy than those in the high-risk group (46.59% vs 35.34%, P = 0.008). We also found that the expression levels of these prognostic MTGs were significantly associated with drug sensitivity in multiple ccRCC cell lines. Our study for the first time elucidates the biological function and prognostic significance of mitochondrial molecules associated with oxidative stress and provides a new protocol for evaluating treatment strategies targeting mitochondria in ccRCC patients.

Upgrade of an old drug: Auranofin in innovative cancer therapies to overcome drug resistance and to increase drug effectiveness

Auranofin is an oral gold(I) compound, initially developed for the treatment of rheumatoid arthritis. Currently, Auranofin is under investigation for oncological application within a drug repurposing plan due to the relevant antineoplastic activity observed both in vitro and in vivo tumor models. In this review, we analysed studies in which Auranofin was used as a single drug or in combination with other molecules to enhance their anticancer activity or to overcome chemoresistance. The analysis of different targets/pathways affected by this drug in different cancer types has allowed us to highlight several interesting targets and effects of Auranofin besides the already well-known inhibition of thioredoxin reductase. Among these targets, inhibitory-κB kinase, deubiquitinates, protein kinase C iota have been frequently suggested. To rationalize the effects of Auranofin by a system biology-like approach, we exploited transcriptomic data obtained from a wide range of cell models, extrapolating the data deposited in the Connectivity Maps website and we attempted to provide a general conclusion and discussed the major points that need further investigation.

Potential effect of EGCG on the anti-tumor efficacy of metformin in melanoma cells

Metformin, a first-line drug for type 2 diabetes mellitus, has been recognized as a potential anti-tumor agent in recent years. Epigallocatechin-3-gallate (EGCG), as the dominant catechin in green tea, is another promising adjuvant agent for tumor prevention. In the present work, the potential effect of EGCG on the anti-tumor efficacy of metformin in a mouse melanoma cell line (B16F10) was investigated. Results indicated that EGCG and metformin exhibited a synergistic effect on cell viability, migration, and proliferation, as well as signal transducer and activator of transcription 3/nuclear factor-κB (STAT3/NF-κB) pathway signaling and the production of inflammation cytokines. Meanwhile, the combination showed an antagonistic effect on cell apoptosis and oxidative stress levels. The combination of EGCG and metformin also differentially affected the nucleus (synergism) and cytoplasm (antagonism) of B16F10 cells. Our findings provide new insight into the potential effects of EGCG on the anti-tumor efficacy of metformin in melanoma cells.

Non-Thermal Atmospheric Pressure Argon-Sourced Plasma Flux Promotes Wound Healing of Burn Wounds and Burn Wounds with Infection in Mice through the Anti-Inflammatory Macrophages

Plasma medicine is the utilization of gas ionization that might be beneficial for the treatment of burn wounds, a healthcare problem with a significant mortality rate. Due to a lack of information on the impact of plasma flux in immune cells and a high prevalence of bacterial infection in burn wounds, non-thermal argon-based plasma flux was tested on macrophages (RAW246.7) and in mouse models of burn wounds with or without Staphylococcus aureus infection. Accordingly, plasma flux enhanced reactive oxygen species (ROS), using dihydroethidium assay, and decreased abundance of NF-κB-p65 (Western blot analysis) in non-stimulating macrophages. In parallel, plasma flux upregulated IL-10 gene expression (an anti-inflammatory cytokine) in lipopolysaccharide (LPS)-induced inflammatory macrophages, while downregulating the pro-inflammatory cytokines (IL-1β and IL-6). Additionally, plasma flux improved the migratory function of fibroblasts (L929) (fibroblast scratch assay) but not fibroblast proliferation. Moreover, once daily plasma flux administration for 7 days promoted the healing process in burn wounds with or without infection (wound area and wound rank score). Additionally, plasma flux reduced tissue cytokines (TNF-α and IL-6) in burn wounds with infection and promoted collagen in burn wounds without infection. In conclusion, plasma flux induced anti-inflammatory macrophages and promoted the burn-wound healing process partly through the decrease in macrophage NF-κB. Hence, plasma flux treatment should be tested in patients with burn wounds.

SIRT3 overexpression and epigenetic silencing of catalase regulate ROS accumulation in CLL cells activating AXL signaling axis

Mitochondrial metabolism is the key source for abundant ROS in chronic lymphocytic leukemia (CLL) cells. Here, we detected significantly lower superoxide anion (O₂⁻) levels with increased accumulation of hydrogen peroxide (H₂O₂) in CLL cells vs. normal B-cells. Further analysis indicated that mitochondrial superoxide dismutase (SOD)2, which converts O₂⁻ into H₂O₂ remained deacetylated in CLL cells due to SIRT3 overexpression resulting its constitutive activation. In addition, catalase expression was also reduced in CLL cells suggesting impairment of H₂O₂-conversion into water and O₂ which may cause H₂O₂-accumulation. Importantly, we identified two CpG-islands in the catalase promoter and discovered that while the distal CpG-island (−3619 to −3765) remained methylated in both normal B-cells and CLL cells, variable degrees of methylation were discernible in the proximal CpG-island (−174 to −332) only in CLL cells. Finally, treatment of CLL cells with a demethylating agent increased catalase mRNA levels. Functionally, ROS accumulation in CLL cells activated the AXL survival axis while upregulated SIRT3, suggesting that CLL cells rapidly remove highly reactive O₂⁻ to avoid its cytotoxic effect but maintain increased H₂O₂-level to promote cell survival. Therefore, abrogation of aberrantly activated cell survival pathways using antioxidants can be an effective intervention in CLL therapy in combination with conventional agents.

Gold Cluster Capped with a BCL-2 Antagonistic Peptide Exerts Synergistic Antitumor Activity in Chronic Lymphocytic Leukemia Cells

Chronic lymphocytic leukemia (CLL) is still incurable by conventional chemotherapy due to the resistance to apoptosis. We have previously found that a peptide-capped gold cluster (Au₂₅Sv₉) can target on the aberrant oxidative stress in CLL cells to specially inhibit thioredoxin reductase (TrxR) activity, resulting in significant apoptosis. However, the required doses of the gold cluster for inducing apoptosis are high, restricting its potential for further applications. Notably, the most recent studies suggested that CLL cells overexpressed antiapoptotic BCL-2 protein to prevent chemotherapy-induced apoptosis, indicating that BCL-2 could be a promising target for CLL therapy. Regrettably, the nonmitochondrial-targeted Au₂₅Sv₉ has little effect on BCL-2. In this study, we successfully screened a modified BADBH3 peptide (B1P) that could antagonize BCL-2 protein in CLL cells. We found that B1P could effectively sensitize MEC-1 cells to a subliminal dose of Au₂₅Sv₉. To simplify the treatment regimen, we directly fabricated a gold cluster capped with the B1P peptides by one-step synthesis to integrate the BCL-2 antagonistic activity into the gold the cluster, named BGC. We already found that low doses of BGC could significantly induce more apoptosis in MEC-1 cells than equivalent doses of the Au₂₅Sv₉ cluster or B1P peptide alone. Mechanistically, in addition to the inherent inhibitory effect of gold clusters on TrxR activity, BGC could bind to BCL-2 on mitochondria and activate the BCL-2 family-mediated mitochondrial apoptosis cascade more effectively. These results demonstrated that antagonizing the overexpressed BCL-2 in CLL cells, together with inhibiting TrxR simultaneously by a single gold cluster, is a promising strategy for the treatment of CLL cells. This study will provide a paradigm and reference for the development of functionalized gold clusters with rationally designed peptides, and opens up a new opportunity for the treatment of CLL in clinical settings.

Moonlighting Metabolic Enzymes in Cancer: New Perspectives on the Redox Code

Significance: Metabolic reprogramming is considered to be a critical adaptive biological event that fulfills the energy and biomass demands for cancer cells. One hallmark of metabolic reprogramming is reduced oxidative phosphorylation and enhanced aerobic glycolysis. Such metabolic abnormalities contribute to the accumulation of reactive oxygen species (ROS), the by-products of metabolic pathways. Emerging evidence suggests that ROS can in turn directly or indirectly affect the expression, activity, or subcellular localization of metabolic enzymes, contributing to the moonlighting functions outside of their primary roles. This review summarizes the multifunctions of metabolic enzymes and the involved redox modification patterns, which further reveal the inherent connection between metabolism and cellular redox state. Recent Advances: These noncanonical functions of metabolic enzymes involve the regulation of epigenetic modifications, gene transcription, post-translational modification, cellular antioxidant capacity, and many other fundamental cellular events. The multifunctional properties of metabolic enzymes further expand the metabolic dependencies of cancer cells, and confer cancer cells with a means of adapting to diverse environmental stimuli. Critical Issues: Deciphering the redox-manipulated mechanisms with specific emphasis on the moonlighting function of metabolic enzymes is important for clarifying the pertinence between metabolism and redox processes. Future Directions: Investigation of the redox-regulated moonlighting functions of metabolic enzymes will shed new lights into the mechanism by which metabolic enzymes gain noncanonical functions, and yield new insights into the development of novel therapeutic strategies for cancer treatment by targeting metabolic-redox abnormalities. Antioxid. Redox Signal. 34, 979-1003.

Assessment of Phenylboronic Acid Nitrogen Mustards as Potent and Selective Drug Candidates for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) has limited treatment options and the worst prognosis among all types of breast cancer. We describe two prodrugs, namely, CWB-20145 (1) and its methyl analogue FAN-NM-CH3 (2) that reduced the size of TNBC-derived tumors. The DNA cross-linking of nitrogen mustard prodrugs 1 and 2 was superior to that of chlorambucil and melphalan once activated in the presence of H2O2. The cellular toxicity of 1 and 2 was demonstrated in seven human cancer cell lines. The TNBC cell line MDA-MB-468 was particularly sensitive toward 1 and 2. Compound 2 was 10 times more cytotoxic than chlorambucil and 16 times more active than melphalan. An evaluation of the gene expression demonstrated an upregulation of the tumor suppressor genes p53 and p21 supporting a transcriptional mechanism of a reduced tumor growth. Pharmacokinetic studies with 1 showed a rapid conversion of the prodrug. The introduction of a methyl group generated 2 with an increased half-life. An in vivo toxicity study in mice demonstrated that both prodrugs were less toxic than chlorambucil. Compounds 1 and 2 reduced tumor growth with an inhibition rate of more than 90% in athymic nude mice xenografted with MDA-MB-468 cells. Together, the in vivo investigations demonstrated that treatment with 1 and 2 suppressed tumor growth without affecting normal tissues in mice. These phenylboronic acid nitrogen mustard prodrugs represent promising drug candidates for the treatment of TNBC. However, the mechanisms underlying their superior in vivo activity and selectivity as well as the correlation between H2O2 level and in vivo efficacy are not yet fully understood.

Protein kinase C-β-dependent changes in the glucose metabolism of bone marrow stromal cells of chronic lymphocytic leukemia

Survival of chronic lymphocytic leukemia (CLL) cells critically depends on the support of an adapted and therefore appropriate tumor microenvironment. Increasing evidence suggests that B-cell receptor-associated kinases such as protein kinase C-β (PKCβ) or Lyn kinase are essential for the formation of a microenvironment supporting leukemic growth. Here, we describe the impact of PKCβ on the glucose metabolism in bone marrow stromal cells (BMSC) upon CLL contact. BMSC get activated by CLL contact expressing stromal PKCβ that diminishes mitochondrial stress and apoptosis in CLL cells by stimulating glucose uptake. In BMSC, the upregulation of PKCβ results in increased mitochondrial depolarization and leads to a metabolic switch toward oxidative phosphorylation. In addition, PKCβ-deficient BMSC regulates the expression of Hnf1 promoting stromal insulin signaling after CLL contact. Our data suggest that targeting PKCβ and the glucose metabolism of the leukemic niche could be a potential therapeutic strategy to overcome stroma-mediated drug resistance.

Chronic Lymphocytic Leukemia

Patients with chronic lymphocytic leukemia can be divided into three categories: those who are minimally affected by the problem, often never requiring therapy; those that initially follow an indolent course but subsequently progress and require therapy; and those that from the point of diagnosis exhibit an aggressive disease necessitating treatment. Likewise, such patients pass through three phases: development of the disease, diagnosis, and need for therapy. Finally, the leukemic clones of all patients appear to require continuous input from the exterior, most often through membrane receptors, to allow them to survive and grow. This review is presented according to the temporal course that the disease follows, focusing on those external influences from the tissue microenvironment (TME) that support the time lines as well as those internal influences that are inherited or develop as genetic and epigenetic changes occurring over the time line. Regarding the former, special emphasis is placed on the input provided via the B-cell receptor for antigen and the C-X-C-motif chemokine receptor-4 and the therapeutic agents that block these inputs. Regarding the latter, prominence is laid upon inherited susceptibility genes and the genetic and epigenetic abnormalities that lead to the developmental and progression of the disease.

Different mechanisms of arsenic related signaling in cellular proliferation, apoptosis and neo-plastic transformation

Arsenic is a toxic heavy metal vastly dispersed all over the earth crust. It manifests several major adverse health issues to millions of arsenic exposed populations. Arsenic is associated with different types of cancer, cardiovascular disorders, diabetes, hypertension and many other diseases. On the contrary, arsenic (arsenic trioxide, As₂O₃) is used as a chemotherapeutic agent in the treatment of acute promyelocytic leukemia. Balance between arsenic induced cellular proliferations and apoptosis finally decide the outcome of its transformation rate. Arsenic propagates signals via cellular and nuclear pathways depending upon the chemical nature, and metabolic-fates of the arsenical compounds. Arsenic toxicity is propagated via ROS induced stress to DNA-repair mechanism and mitochondrial stability in the cell. ROS induced alteration in p53 regulation and some mitogen/ oncogenic functions determine the transformation outcome influencing cyclin-cdk complexes. Growth factor regulator proteins such as c-Jun, c-fos and c-myc are influenced by chronic arsenic exposure. In this review we have delineated arsenic induced ROS regulations of epidermal growth factor receptor (EGFR), NF-ĸβ, MAP kinase, matrix-metalloproteinases (MMPs). The role of these signaling molecules has been discussed in relation to cellular apoptosis, cellular proliferation and neoplastic transformation. The arsenic stimulated pathways which help in proliferation and neoplastic transformation ultimately resulted in cancer manifestation whereas apoptotic pathways inhibited carcinogenesis. Therapeutic strategies against arsenic should be designed taking into account all these factors.

Fluorescent probe for the imaging of superoxide and peroxynitrite during drug-induced liver injury

Drug-induced liver injury (DILI) is an important cause of potentially fatal liver disease. Herein, we report the development of a molecular probe (LW-OTf) for the detection and imaging of two biomarkers involved in DILI. Initially, primary reactive oxygen species (ROS) superoxide (O₂˙^-) selectively activates a near-infrared fluorescence (NIRF) output by generating fluorophore LW-OH. The C[double bond, length as m-dash]C linker of this hemicyanine fluorophore is subsequently oxidized by reactive nitrogen species (RNS) peroxynitrite (ONOO^-), resulting in cleavage to release xanthene derivative LW-XTD, detected using two-photon excitation fluorescence (TPEF). An alternative fluorescence pathway can occur through cleavage of LW-OTf by ONOO^- to non-fluorescent LW-XTD-OTf, which can react further with the second analyte O₂˙^- to produce the same LW-XTD fluorescent species. By combining NIRF and TPEF, LW-OTf is capable of differential and simultaneous detection of ROS and RNS in DILI using two optically orthogonal channels. Probe LW-OTf could be used to detect O₂˙^- or O₂˙^- and ONOO^- in lysosomes stimulated by 2-methoxyestradiol (2-ME) or 2-ME and SIN-1 respectively. In addition, we were able to monitor the chemoprotective effects of tert-butylhydroxyanisole (BHA) against acetaminophen (APAP) toxicity in living HL-7702 cells. More importantly, TPEF and NIRF imaging confirmed an increase in levels of both O₂˙^- and ONOO^- in mouse livers during APAP-induced DILI (confirmed by hematoxylin and eosin (H&E) staining).

Oxidative Damage of Tryptophan Hydroxylase-2 Mediated by Peroxisomal Superoxide Anion Radical in Brains of Mouse with Depression

Depression is intimately linked with oxidative stress in the brains. Peroxisome plays vital roles in the regulation of intracellular redox balance by keeping reactive oxygen species (ROS) homeostasis. Available evidence indicates a possible relationship between peroxisomal ROS and depression. Even so, the underlying modulation mechanisms of peroxisomal ROS in depression are still rudimentary due to the limitations of the existing detecting methods. Hence, we developed a two-photon fluorescent probe TCP for the real-time visualization of the first produced ROS superoxide anion radical (O₂^•-) in peroxisome. Using the two-photon fluorescence imaging, we found that peroxisomal O₂^•- rose during oxidative stress in the mouse brains, resulting in the inactivation of catalase (CAT). Subsequently, the intracellular H₂O₂ level elevated, which further oxidized tryptophan hydroxylase-2 (TPH2). Then the decrease contents of TPH2 caused the dysfunction of 5-hydroxytryptamine (5-HT) system in the mouse brains, eventually leading to depression-like behaviors. Our work provides evidence of a peroxisomal O₂^•- mediated signaling pathway in depression, which will conduce to pinpoint potential targets for the treatment of depression.

Evaluation of anticancer role of a novel ruthenium(II)-based compound compared with NAMI-A and cisplatin in impairing mitochondrial functionality and promoting oxidative stress in triple negative breast cancer models

Platinum-based compounds are the most widely used anticancer drugs but, their elevated toxicity and chemoresistance has stimulated the study of others, such as ruthenium-based compounds. NAMI-A and UNICAM-1 were tested in vitro, comparing the mechanisms of toxicity, in terms of mitochondrial functionality and cellular oxidative stress. UNICAM-1, showed a clear mitochondrial target and a cytotoxic dose-dependent response thanks to its ability to promote an imbalance of cellular redox status. It impaired directly mitochondrial respiratory chain, promoting mitochondrial superoxide anion production, leading to mitochondrial membrane depolarization. All these aspects, could make UNICAM-1 a valid alternative for chemotherapy treatment of breast cancer.

Ascorbic acid (vitamin C) synergistically enhances the therapeutic effect of targeted therapy in chronic lymphocytic leukemia

Background

Novel, less toxic, cost-effective and safe therapeutic strategies are needed to improve treatment of chronic lymphocytic leukemia (CLL). Ascorbic acid (AA, vitamin C) has shown a potential anti-cancer therapeutic activity in several cancers. However, the anti-cancer effects of ascorbic acid on CLL B-cells have not been extensively studied. We aimed in this study to evaluate the in vitro therapeutic activity using clinically relevant conditions.

Methods

Primary CLL B-cells and two CLL cell lines were exposed to a dose that is clinically achievable by AA oral administration (250 μM), and cell death and potential mechanisms were assessed. The role of the protective CLL microenvironment was studied. Synergistic interaction between AA and CLL approved drugs (Ibrutinib, Idelalisib and Venetoclax) was also evaluated.

Results

Ascorbic acid is cytotoxic for CLL B-cells at low dose (250 μM) but spares healthy B-cells. Ascorbic-acid-induced cytotoxicity involved pro-oxidant damage through the generation of reactive oxygen species in the extracellular media and in CLL cells, and induced caspase-dependent apoptosis. We also found that AA treatment overcame the supportive survival effect provided by microenvironment including bone marrow mesenchymal stem cells, T-cell cues (CD40L + IL-4), cytokines and hypoxia. Our data suggest that resistance to AA could be mediated by the expression of the enzyme catalase in some CLL samples and by the glucose metabolite pyruvate. We also demonstrated that AA synergistically potentiates the cytotoxicity of targeted therapies used in or being developed for CLL.

Conclusion

These preclinical results point to AA as an adjuvant therapy with potential to further improve CLL treatments in combination with targeted therapies.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13046-020-01738-0.

Nanomaterial-mediated autophagy: coexisting hazard and health benefits in biomedicine

BACKGROUND

Widespread biomedical applications of nanomaterials (NMs) bring about increased human exposure risk due to their unique physicochemical properties. Autophagy, which is of great importance for regulating the physiological or pathological activities of the body, has been reported to play a key role in NM-driven biological effects both in vivo and in vitro. The coexisting hazard and health benefits of NM-mediated autophagy in biomedicine are nonnegligible and require our particular concerns.

MAIN BODY

We collected research on the toxic effects related to NM-mediated autophagy both in vivo and in vitro. Generally, NMs can be delivered into animal models through different administration routes, or internalized by cells through different uptake pathways, exerting varying degrees of damage in tissues, organs, cells, and organelles, eventually being deposited in or excreted from the body. In addition, other biological effects of NMs, such as oxidative stress, inflammation, necroptosis, pyroptosis, and ferroptosis, have been associated with autophagy and cooperate to regulate body activities. We therefore highlight that NM-mediated autophagy serves as a double-edged sword, which could be utilized in the treatment of certain diseases related to autophagy dysfunction, such as cancer, neurodegenerative disease, and cardiovascular disease. Challenges and suggestions for further investigations of NM-mediated autophagy are proposed with the purpose to improve their biosafety evaluation and facilitate their wide application. Databases such as PubMed and Web of Science were utilized to search for relevant literature, which included all published, Epub ahead of print, in-process, and non-indexed citations.

CONCLUSION

In this review, we focus on the dual effect of NM-mediated autophagy in the biomedical field. It has become a trend to use the benefits of NM-mediated autophagy to treat clinical diseases such as cancer and neurodegenerative diseases. Understanding the regulatory mechanism of NM-mediated autophagy in biomedicine is also helpful for reducing the toxic effects of NMs as much as possible.

Naringin Combined with NF-κB Inhibition and Endoplasmic Reticulum Stress Induces Apoptotic Cell Death via Oxidative Stress and the PERK/eIF2α/ATF4/CHOP Axis in HT29 Colon Cancer Cells

Currently, combination therapy is considered the most effective solution for a selective chemotherapeutic effect in the treatment of colon cancer. This study investigated the death of both colon cancer HT29 cells and healthy vascular smooth muscle TG-Ha-VSMC cells (VSMCs) induced by naringin combined with endoplasmic reticulum (ER) stress and NF-κB inhibition. Naringin combined with tunicamycin and BAY 11-7082 suppressed the proliferation of HT29 cells in a dose-dependent manner and induced particularly apoptotic death without significantly affecting healthy VSMCs according to Annexin V/PI staining and AO/EB staining analyses. Insufficient antioxidant defense and heat shock response as well as excessive ROS generation were observed in HT29 cells following combination therapy. Quantitative real-time PCR and western blot analysis demonstrated that drug combination-induced mitochondrial apoptosis was activated through the ROS-mediated PERK/eIF2α/ATF4/CHOP pathway. Additionally, naringin combination significantly reduced the sXBP expression induced by tunicamycin+BAY 11-7082 in a dose-dependent manner. In conclusion, this study found that naringin combined with tunicamycin+BAY 11-7082 efficiently induced apoptotic cell death in HT29 colon cancer cells via oxidative stress and the PERK/eIF2α/ATF4/CHOP pathway, suggesting that naringin combined with tunicamycin plus BAY 11-7082 could be a new combination therapy strategy for effective colon cancer treatment with minimal side effects on healthy cells.

The Role of Necroptosis in ROS-Mediated Cancer Therapies and Its Promising Applications

Over the past decades, promising therapies targeting different signaling pathways have emerged. Among these pathways, apoptosis has been well investigated and targeted to design diverse chemotherapies. However, some patients are chemoresistant to these therapies due to compromised apoptotic cell death. Hence, exploring alternative treatments aimed at different mechanisms of cell death seems to be a potential strategy for bypassing impaired apoptotic cell death. Emerging evidence has shown that necroptosis, a caspase-independent form of cell death with features between apoptosis and necrosis, can overcome the predicament of drug resistance. Furthermore, previous studies have also indicated that there is a close correlation between necroptosis and reactive oxygen species (ROS); both necroptosis and ROS play significant roles both under human physiological conditions such as the regulation of inflammation and in cancer biology. Several small molecules used in experiments and clinical practice eliminate cancer cells via the modulation of ROS and necroptosis. The molecular mechanisms of these promising therapies are discussed in detail in this review.

The Significance of Mitochondrial Dysfunction in Cancer

As an essential organelle in nucleated eukaryotic cells, mitochondria play a central role in energy metabolism, maintenance of redox balance, and regulation of apoptosis. Mitochondrial dysfunction, either due to the TCA cycle enzyme defects, mitochondrial DNA genetic mutations, defective mitochondrial electron transport chain, oxidative stress, or aberrant oncogene and tumor suppressor signaling, has been observed in a wide spectrum of human cancers. In this review, we summarize mitochondrial dysfunction induced by these alterations that promote human cancers.

Mitochondria-targeted 1,4-naphthoquinone (SkQN) is a powerful prooxidant and cytotoxic agent

An increase in the production of reactive oxygen species (ROS) in mitochondria due to targeted delivery of redox active compounds may be useful in studies of modulation of cell functions by mitochondrial ROS. Recently, the mitochondria-targeted derivative of menadione (MitoK₃) was synthesized. However, MitoK₃ did not induce mitochondrial ROS production and lipid peroxidation while exerting significant cytotoxic action. Here we synthesized 1,4-naphthoquinone conjugated with alkyltriphenylphosphonium (SkQN) as a prototype of mitochondria-targeted prooxidant, and its redox properties, interactions with isolated mitochondria, yeast cells and various human cell lines were investigated. According to electrochemical measurements, SkQN was more active redox agent and, due to the absence of methyl group in the naphthoquinone ring, more reactive as electrophile than MitoK₃. SkQN (but not MitoK₃) stimulated hydrogen peroxide production in isolated mitochondria. At low concentrations, SkQN stimulated state 4 respiration in mitochondria, decreased membrane potential, and blocked ATP synthesis, being more efficient uncoupler of oxidative phosphorylation than MitoK₃. In yeast cells, SkQN decreased cell viability and induced oxidative stress and mitochondrial fragmentation. SkQN killed various tumor cells much more efficiently than MitoK₃. Since many tumors are characterized by increased oxidative stress, the use of new mitochondria-targeted prooxidants may be a promising strategy for anticancer therapy.

cROSsing the Line: Between Beneficial and Harmful Effects of Reactive Oxygen Species in B-Cell Malignancies

B-cell malignancies are a heterogeneous group of hematological neoplasms derived from cells at different stages of B-cell development. Recent studies revealed that dysregulated redox metabolism is one of the factors contributing to the pathogenesis and progression of B-cell malignancies. Elevated levels of oxidative stress markers usually correlate with the advanced stage of various B-cell malignancies. In the complex tumor microenvironment, reactive oxygen species affect not only malignant cells but also bystander cells, including immune cells. Importantly, malignant cells, due to genetic dysregulation, are able to adapt to the increased demands for energy and reducing equivalents via metabolic reprogramming and upregulation of antioxidants. The immune cells, however, are more sensitive to oxidative imbalance. This may cause their dysfunction, leading to immune evasion and tumor progression. On the other hand, the already imbalanced redox homeostasis renders malignant B-cells particularly sensitive to further elevation of reactive oxygen species. Indeed, targeting antioxidant systems has already presented anti-leukemic efficacy in preclinical models. Moreover, the prooxidant treatment that triggers immunogenic cell death has been utilized to generate autologous anti-leukemic vaccines. In this article, we review novel research on the dual role of the reactive oxygen species in B-cell malignancies. We highlight the mechanisms of maintaining redox homeostasis by malignant B-cells along with the antioxidant shield provided by the microenvironment. We summarize current findings regarding therapeutic targeting of redox metabolism in B-cell malignancies. We also discuss how the oxidative stress affects antitumor immune response and how excessive reactive oxygens species influence anticancer prooxidant treatments and immunotherapies.

A Novel Flow Cytometric Assay to Identify Inhibitors of RBPJ-DNA Interactions

Notch signaling is often involved in cancer cell initiation and proliferation. Aberrant Notch activation underlies more than 50% of T-cell acute lymphoblastic leukemia (T-ALL); accordingly, chemicals disrupting Notch signaling are of potential to treat Notch-dependent cancer. Here, we developed a flow cytometry-based high-throughput assay to identify compounds that disrupt the interactions of DNA and RBPJ, the major downstream effector of Notch signaling. From 1492 compounds, we identified 18 compounds that disrupt RBPJ-DNA interactions in a dose-dependent manner. Cell-based assays further revealed that auranofin downregulates Notch-dependent transcription and decreases RBPJ-chromatin interactions in cells. Most strikingly, T-ALL cells that depend on Notch signaling for proliferation are more sensitive to auranofin treatment, supporting the notion that auranofin downregulates Notch signaling by disrupting RBPJ-DNA interaction. These results validate the feasibility of our assay scheme to screen for additional Notch inhibitors and provide a rationale to further test the use of auranofin in treating Notch-dependent cancer.

Antioxidant Properties and Redox-Modulating Activity of Chitosan and Its Derivatives: Biomaterials with Application in Cancer Therapy

Many studies have shown that mitochondrial metabolism has a fundamental role in induction of carcinogenesis due to the influence of increased levels of reactive oxygen species (ROS) generation in all steps of oncogene transformation and cancer progression. It is widely accepted that the anticancer effect of conventional anticancer drugs is due to induction of oxidative stress and elevated intracellular levels of ROS, which alter the redox homeostasis of cancer cells. On the other hand, the harmful side effects of conventional anticancer chemotherapeutics are also due to increased production of ROS and disruption of redox homeostasis of normal cells and tissues. Therefore, there is a growing interest toward the development of natural antioxidant compounds from various sources, which could impact the redox state of cancer and normal cells by different pathways and could prevent damage from oxidant-mediated reactions. It is known that chitosan exhibits versatile biological properties, including biodegradability, biocompatibility, and a less toxic nature. Because of its antioxidant, antibacterial, anticancer, anti-inflammatory, and immunostimulatory activities, the biopolymer has been used in a wide variety of pharmaceutical, biomedical, food industry, health, and agricultural applications and has been classified as a new physiologically bioactive material.

DNA Adducts as Biomarkers To Predict, Prevent, and Diagnose Disease-Application of Analytical Chemistry to Clinical Investigations

Characterization of the chemistry, structure, formation, and metabolism of DNA adducts has been one of the most significant contributions to the field of chemical toxicology. This work provides the foundation to develop analytical methods to measure DNA adducts, define their relationship to disease, and establish clinical tests. Monitoring exposure to environmental and endogenous toxicants can predict, diagnose, and track disease as well as guide therapeutic treatment. DNA adducts are one of the most promising biomarkers of toxicant exposure owing to their stability, appearance in numerous biological matrices, and characteristic analytical properties. In addition, DNA adducts can induce mutations to drive disease onset and progression and can serve as surrogate markers of chemical exposure. In this perspective, we highlight significant advances made within the past decade regarding DNA adduct quantitation using mass spectrometry. We hope to expose a broader audience to this field and encourage analytical chemistry laboratories to explore how specific adducts may be related to various pathologies. One of the limiting factors in developing clinical tests to measure DNA adducts is cohort size; ideally, the cohort would allow for model development and then testing of the model to the remaining cohort. The goals of this perspective article are to (1) provide a summary of analyte levels measured using state-of-the-art analytical methods, (2) foster collaboration, and (3) highlight areas in need of further investigation.

In vivo pharmacodynamic evaluation of antidepressants based on flux mitochondrial Cys in living mice via near infrared fluorescence imaging

We proposed a new strategy for in vivo evaluation of antidepressants through NIRF imaging for mitochondrial Cys in the mouse brain.

In situ and real-time imaging of superoxide anion and peroxynitrite elucidating arginase 1 nitration aggravating hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion (IR) injury is dynamically regulated by intertwined superoxide anion (O2-)-peroxynitrite (ONOO-) cascaded molecules. Arginase 1 involves in O2-/ONOO- fluctuations and is strongly connected to IR injury. A few probes have been innovated to measure intracellular O2- or ONOO- by fluorescent imaging separately, but revealing the definite link of O2-, ONOO- and arginase 1 in situ remains unidentified in hepatic IR. Thus, a well-designed dual-color two-photon fluorescence probe (CyCA) was created for the in situ real-time detection of O2--ONOO-. Surprisingly, CyCA exhibited a suitable combination of high specificity, preeminent sensitivity, exclusive mitochondria-targeting and fast-response. On the basis of remarkable advantages, we successfully applied CyCA to visualize endogenous O2- and ONOO- in living cells and mice. The synergistic elevation of mitochondrial O2--ONOO- in IR mice was observed for the first time. Furthermore, three tyrosine nitration-sites in arginase 1 caused by ONOO- were identified in proteomic analysis, which was never reported previously. Attractively, nitro-modified arginase 1 could further promote ONOO- formation, ultimately exacerbating the intracellular redox imbalance and IR injury. These new findings decipher direct molecular links of O2--ONOO--arginase 1, and suggest effective strategies for the prevention and treatment of IR injury.

Local Tumor Ischemia-Reperfusion Mediated By Ultrasound-Targeted Microbubble Destruction Enhances The Anti-Tumor Efficacy Of Doxorubicin Chemotherapy

Background

Ultrasound-targeted microbubble destruction (UTMD) has been shown to be a promising noninvasive technique to change the tumor circulation, thus providing a potential method to increase reactive oxygen species (ROS) levels in tumors by inducing tumor tissue ischemia-reperfusion (IR). In this study, we investigated the feasibility of local tumor IR through UTMD to enhance the anti-tumor efficacy of doxorubicin (DOX) chemotherapy.

Methods

UTMD was used to induce local tumor IR. After the major blood supply of the tumor was restored, DOX was intravenously injected into the tumor-bearing mice. The superoxide dismutase (SOD) and catalase (CAT) activity and ROS levels were examined, and the anti-tumor efficacy was evaluated.

Results

UTMD blocked the circulation to the tumor for 30 mins. Slow reperfusion began to occur after 30 mins, and major blood supply was restored after 1 hr. The blood perfusion of the tumor completely recovered at 2 hrs. The activity of SOD in the tumors was significantly decreased at 2 hrs and 1 day after IR treatment with or without DOX treatment. The CAT activity showed no obvious changes at 2 hrs after IR treatment, whereas a significant decrease was found after 1 day in both the IR and DOX/IR groups. Moreover, higher levels of ROS were produced in the IR group and IR/DOX group. In vivo anti-tumor study indicated that the local tumor IR strategy may significantly enhance the anti-tumor efficacy of DOX chemotherapy.

Conclusion

UTMD provides a novel, simple and non-invasive technique for tumor IR. In combination with chemotherapy, UTMD may have high great potential to improve the anti-tumor efficacy of chemotherapeutic drugs.

Relationship of oxidative stress in the resistance to imatinib in Tunisian patients with chronic myeloid leukemia: A retrospective study

Background

This work aimed to evaluate oxidative stress in chronic myeloid leukemia (CML) patients treated with tunisian (IM) vs controls and in CML patients with resistance to IM vs patients without resistance to IM.

Methods

The study included 40 CML patients and 34 controls. Of 40 patients with CML, 26 patients were developed in resistance to IM. The oxidant/antioxidant markers were evaluated by spectrophotometric methods for all used samples.

Results

For CML patients, increased malondialdehyde (MDA) and advanced oxidation protein products (AOPP) levels were found compared to controls (P < .001; P = .01). Higher catalase (CAT) activity (P = .048) and lower superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, reduced Glutathione (GSH) and vitamin C levels were found in CML patients (P < .001). The comparison between the resistant vs no‐resistant CML patients revealed higher MDA level (P = .02) and CAT and SOD activities in IM‐resistant patients (P = .04, P = .03). GPx activity was reduced (P = .04). Furthermore, increased mean ratio of MDA/GSH, MDA/GPx, and SOD/(GPx + CAT) was found in IM‐resistant patients as compared with no‐resistant (P = .01, P = .01, P = .035). The mean ratio of GPx/GSH in the IM‐resistant CML patients was lower than in IM no‐resistant one (P = .039). For IM‐resistant patients, we found negative correlation between MDA level and the ratio SOD/(CAT + GPx) (r = −0.46, P = .002); and positive correlation between SOD and (CAT + GPx) activities (r = 0.38, P = .06) and between GSH level and GPx activity (r = 0.53, P = .01).

Conclusions

Our results have shown a highly disturbed oxidative profile in IM‐resistant CML patients as compared to no‐resistant. The H₂O₂ has a key role in the resistance to IM treatment.