Molecular and Cellular Effects of Hydrogen Peroxide on Human Lung Cancer Cells: Potential Therapeutic Implications

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 biocompatible chitosan-based fluorescent polymer for efficient H2O2 detection in living cells and water samples

As a biomarker of oxidative stress, hydrogen peroxide (H2O2) plays a complex role in organisms, including regulating cell signaling, respiration, the immune system, and other life processes. Therefore, it is important to develop a tool that can simply and effectively monitor H2O2 levels in organisms and the environment. In this work, naphthalene fluorophores with a borate structure were introduced into chitosan (CTS) azide, and a CTS-based fluorescence sensor (CTS-HP) was designed for sensitive H2O2 detection. The biocompatibility and degradability of CTS endowed CTS-HP with reduced biotoxicity compared with organic fluorescent dyes, and the substitution degree of fluorophores on the CTS chains was 0.703. The randomly coiled chain structure of the CTS-HP probe enabled the boronic acid recognition sites on the fluorophores to achieve the enrichment of analyte H2O2 through a synergistic effect. Therefore, the probe CTS-HP (10 μg mL-1) exhibited a 21-fold fluorescence enhancement and good detection limit (LOD = 8.98 nM) in H2O2 solution, reaching the maximum fluorescence response faster (within 16 min). The probe also successfully achieved the fluorescence imaging of endogenous and exogenous H2O2 in zebrafish and living cells and labeled the recovery experiment of H2O2 in real water samples (recoveries rates of 90.93-102.9 % and RSD < 3.09 %).

Static Magnetic Field Reduces Intracellular ROS Levels and Protects Cells Against Peroxide-Induced Damage: Suggested Roles for Catalase

A feature in neurodegenerative disorders is the loss of neurons, caused by several factors including oxidative stress induced by reactive oxygen species (ROS). In this work, static magnetic field (SMF) was applied in vitro to evaluate its effect on the viability, proliferation, and migration of human neuroblastoma SH-SY5Y cells, and on the toxicity induced by hydrogen peroxide (H2O2), tert-butyl hydroperoxide (tBHP), H2O2/sodium azide (NaN3) and photosensitized oxidations by photodynamic therapy (PDT) photosensitizers. The SMF increased almost twofold the cell expression of the proliferation biomarker Ki-67 compared to control cells after 7 days of exposure. Exposure to SMF accelerated the wound healing of scratched cell monolayers and significantly reduced the H2O2-induced and the tBHP-induced cell deaths. Interestingly, SMF was able to revert the effects of NaN3 (a catalase inhibitor), suggesting an increased activity of catalase under the influence of the magnetic field. In agreement with this hypothesis, SMF significantly reduced the oxidation of DCF-H2, indicating a lower level of intracellular ROS. When the redox imbalance was triggered through photosensitized oxidation, no protection was observed. This observation aligns with the proposed role of catalase in cellular proctetion under SMF.  Exposition to SMF should be further validated in vitro and in vivo as a potential therapeutic approach for neurodegenerative disorders.

CNT-FET for sensitive hydrogen peroxide biosensing via immobilized Cytochrome c

H₂O₂ is an effective substance in the body which contributes to gene expression, insulin metabolism and determining cell shapes. However, a high concentration of H₂O₂ is harmful to the body and can cause various diseases such as colitis wounds, sepsis disease, lymphocyte proliferation and macrophage apoptosis in systemic lupus erythematosus. In this study, a Cyt c/cMWCNTs/FET was designed to real-time detect H₂O₂ via immobilized Cyt c on the cMWCNTs/FET surface. The performance of the Cyt c/cMWCNTs/FET biosensor was studied under various parameters such as cMWCNTs and Cyt c concentrations, as well as different pH values. When H₂O₂ was added to the reaction chamber of the Cyt c/cMWCNTs/FET, the output current of the Bio-FET was reduced, which was attributed to H₂O₂ detection. The linear response range of this Cyt c/cMWCNT/FET was 10.0 fM to 1.0 nM. The limit of detection and response time of this platform were determined to be 9.13 fM and around 1.0 s, respectively. Also, the operation of the Cyt c/cMWCNTs/FET in the presence of glucose, leucine, tyrosine and ascorbic acid as interfering substances was selective towards H₂O₂.

The oxidative aging model integrated various risk factors in type 2 diabetes mellitus at system level

Background

Type 2 diabetes mellitus (T2DM) is a chronic endocrine metabolic disease caused by insulin dysregulation. Studies have shown that aging-related oxidative stress (as "oxidative aging") play a critical role in the onset and progression of T2DM, by leading to an energy metabolism imbalance. However, the precise mechanisms through which oxidative aging lead to T2DM are yet to be fully comprehended. Thus, it is urgent to integrate the underlying mechanisms between oxidative aging and T2DM, where meaningful prediction models based on relative profiles are needed.

Methods

First, machine learning was used to build the aging model and disease model. Next, an integrated oxidative aging model was employed to identify crucial oxidative aging risk factors. Finally, a series of bioinformatic analyses (including network, enrichment, sensitivity, and pan-cancer analyses) were used to explore potential mechanisms underlying oxidative aging and T2DM.

Results

The study revealed a close relationship between oxidative aging and T2DM. Our results indicate that nutritional metabolism, inflammation response, mitochondrial function, and protein homeostasis are key factors involved in the interplay between oxidative aging and T2DM, even indicating key indices across different cancer types. Therefore, various risk factors in T2DM were integrated, and the theories of oxi-inflamm-aging and cellular senescence were also confirmed.

Conclusion

In sum, our study successfully integrated the underlying mechanisms linking oxidative aging and T2DM through a series of computational methodologies.

In vitro antioxidant activities of Carissa edulis ((Forssk) Vahl) and Pappea capensis (Eckyl. & Zeyh) extracts

Herbal medications are gaining popularity due to their long history of use in traditional medicine. They serve as a reservoir for a diverse array of phytocompounds linked to amelioration of oxidative stress. Oxidative stress is a disturbance in the balance between generation and elimination of reactive species in human body. Moreover, reactive species are implicated in the onset and progression of chronic disorders. The current therapeutic approaches despite showing efficacy are characterized by several limitations such as adverse effects and prohibitive costs. This drives the need to explore alternatives that can inhibit, ameliorate or reverse conditions caused by oxidative stress. Several studies have evaluated antioxidant effects of diverse plant extracts. C. edulis and P. capensis are used as traditional therapy among the African communities to manage oxidative stress-related ailments. However, there is limited research on the antioxidant effects of these medicinal plants. The current study, therefore, sought to evaluate the antioxidant and phytochemical profile, of C. edulis and P. capensis extracts. Samples were collected from Embu County, Kenya. In vitro antioxidant properties of the extracts were evaluated through ferric reduction, Iron chelating, hydroxyl radical, and DPPH radical scavenging activities. Activities of catalase, superoxide dismutase and glutathione reductases of the extracts were further determined. Phytochemical profiles were determined using Liquid Chromatography Mass Spectrophotometer (LC-MS) and Gas Chromatography Mass Spectrophotometer (GC-MS) analyses. The extracts displayed concentration dependent antioxidant activities. Phytochemical analyses revealed presence compounds which are associated with antioxidant activities including flavonoids, phenolics, tocopherols and terpenoids. The findings provide a scientific validation for the folklore use of C. edulis and P. capensis in management of oxidative stress. Nevertheless, there is a need for further purification and characterization of phytochemicals associated with antioxidant activities.

The effects of acute hydrogen peroxide exposure on respiratory cilia motility and viability

COVID-19 has seen the propagation of alternative remedies to treat respiratory disease, such as nebulization of hydrogen peroxide (H₂O₂). As H₂O₂ has known cytotoxicity, it was hypothesised that H₂O₂ inhalation would negatively impact respiratory cilia function. To test this hypothesis, mouse tracheal samples were incubated with different H₂O₂ concentrations (0.1-1%) then cilia motility, cilia generated flow, and cell death was assessed 0-120 min following H₂O₂ treatment. 0.1-0.2% H₂O₂ caused immediate depression of cilia motility and complete cessation of cilia generated flow. Higher H₂O₂ concentrations (≥0.5%) caused immediate complete cessation of cilia motility and cilia generated flow. Cilia motility and flow was restored 30 min after 0.1% H₂O₂ treatment. Cilia motility and flow remained depressed 120 min after 0.2-0.5% H₂O₂ treatment. No recovery was seen 120 min after treatment with ≥1% H₂O₂. Live/dead staining revealed that H₂O₂ treatment caused preferential cell death of ciliated respiratory epithelia over non-ciliated epithelia, with 1% H₂O₂ causing 35.3 ± 7.0% of the ciliated epithelia cells to die 120 min following initial treatment. This study shows that H₂O₂ treatment significantly impacts respiratory cilia motility and cilia generated flow, characterised by a significant impairment in cilia motility even at low concentrations, the complete cessation of cilia motility at higher doses, and a significant cytotoxic effect on ciliated respiratory epithelial cells by promoting cell death. While this data needs further study using in vivo models, it suggests that extreme care should be taken when considering treating respiratory diseases with nebulised H₂O₂.

Differential Sensitivity of Melanoma Cells and Their Non-Cancerous Counterpart to Cold Atmospheric Plasma-Induced Reactive Oxygen and Nitrogen Species

Despite continuous progress in therapy, melanoma is one of the most aggressive and malignant human tumors, often relapsing and metastasizing to almost all organs. Cold atmospheric plasma (CAP) is a novel anticancer tool that utilizes abundant reactive oxygen and nitrogen species (RONS) being deposited on the target cells and tissues. CAP-induced differential effects between non-cancerous and cancer cells were comparatively examined. Melanoma and non-cancerous skin fibroblast cells (counterparts; both cell types were isolated from the same patient) were used for plasma-cell interactions. The production of intracellular RONS, such as nitric oxide (NO), hydroxyl radical (•OH), and hydrogen peroxide (H₂O₂), increased remarkably only in melanoma cancer cells. It was observed that cancer cells morphed from spread to round cell shapes after plasma exposure, suggesting that they were more affected than non-cancerous cells in the same plasma condition. Immediately after both cell types were treated with plasma, there were no differences in the amount of extracellular H₂O₂ production, while Hanks' balanced salt solution-containing cancer cells had lower concentrations of H₂O₂ than that of non-cancerous cells at 1 h after treatment. The melanoma cells seemed to respond to CAP treatment with a greater rise in RONS and a higher consumption rate of H₂O₂ than homologous non-cancerous cells. These results suggest that differential sensitivities of non-cancerous skin and melanoma cells to CAP-induced RONS can enable the applicability of CAP in anticancer therapy.

A New Manganese Superoxide Dismutase Mimetic Improves Oxaliplatin-Induced Neuropathy and Global Tolerance in Mice

Reactive oxygen species (ROS) are produced by every aerobic cell during mitochondrial oxidative metabolism as well as in cellular response to xenobiotics, cytokines, and bacterial invasion. Superoxide Dismutases (SOD) are antioxidant proteins that convert superoxide anions (O2•−) to hydrogen peroxide (H2O2) and dioxygen. Using the differential in the level of oxidative stress between normal and cancer cells, SOD mimetics can show an antitumoral effect and prevent oxaliplatin-induced peripheral neuropathy. New Pt(IV) conjugate prodrugs (OxPt-x-Mn1C1A (x = 1, 1-OH, 2)), combining oxaliplatin and a Mn SOD mimic (MnSODm Mn1C1A) with a covalent link, were designed. Their stability in buffer and in the presence of sodium ascorbate was studied. In vitro, their antitumoral activity was assessed by the viability and ROS production of tumor cell lines (CT16, HCT 116, KC) and fibroblasts (primary culture and NIH 3T3). In vivo, a murine model of colorectal cancer was created with subcutaneous injection of CT26 cells in Balb/c mice. Tumor size and volume were measured weekly in four groups: vehicle, oxaliplatin, and oxaliplatin associated with MnSODm Mn1C1A and the bis-conjugate OxPt-2-Mn1C1A. Oxaliplatin-induced peripheral neuropathy (OIPN) was assessed using a Von Frey test reflecting chronic hypoalgesia. Tolerance to treatment was assessed with a clinical score including four items: weight loss, weariness, alopecia, and diarrhea. In vitro, Mn1C1A associated with oxaliplatin and Pt(IV) conjugates treatment induced significantly higher production of H2O2 in all cell lines and showed a significant improvement of the antitumoral efficacy compared to oxaliplatin alone. In vivo, the association of Mn1C1A to oxaliplatin did not decrease its antitumoral activity, while OxPt-2-Mn1C1A had lower antitumoral activity than oxaliplatin alone. Mn1C1A associated with oxaliplatin significantly decreased OIPN and also improved global clinical tolerance of oxaliplatin. A neuroprotective effect was observed, associated with a significantly improved tolerance to oxaliplatin without impairing its antitumoral activity.

Stratifin as a novel diagnostic biomarker in serum for diffuse alveolar damage

Among the various histopathological patterns of drug-induced interstitial lung disease (DILD), diffuse alveolar damage (DAD) is associated with poor prognosis. However, there is no reliable biomarker for its accurate diagnosis. Here, we show stratifin/14-3-3σ (SFN) as a biomarker candidate found in a proteomic analysis. The study includes two independent cohorts (including totally 26 patients with DAD) and controls (total 432 samples). SFN is specifically elevated in DILD patients with DAD, and is superior to the known biomarkers, KL-6 and SP-D, in discrimination of DILD patients with DAD from patients with other DILD patterns or other lung diseases. SFN is also increased in serum from patients with idiopathic DAD, and in lung tissues and bronchoalveolar lavage fluid of patients with DAD. In vitro analysis using cultured lung epithelial cells suggests that extracellular release of SFN occurs via p53-dependent apoptosis. We conclude that serum SFN is a promising biomarker for DAD diagnosis.

An in vitro redox adaptation model for metastatic prostate cancer: Establishing, characterizing, and Cabazitaxel response evaluating

Little is known about the redox-adapted cancer cells for understanding their pharmacologically targetable features and chemotherapeutic responses. Thus, we presented the first in vitro redox adaptation model for metastatic prostate cancer (mPC), LNCaP-HPR, with enhanced oxidative stress resistance accompanying poor Cabazitaxel response. After establishing, the cells were characterized by comparing the viability, death, oxidative stress, total GSH levels, and the mRNA and protein levels of the redox-sensitive transcription factors responsible for the adaptation, Nrf-2, NF-κB, and HIF-1α. Then, the apoptotic effect of Cabazitaxel was evaluated in LNCaP mPC, LNCaP-HPR, and C4-2 metastatic castration-resistant (mCRPC) cells. In response to H₂ O₂ , viability, oxidative stress, and the total GSH levels of LNCaP-HPR cells have confirmed the oxidative stress resistance. Nrf-2, NF-κB, and HIF-1α were upregulated in LNCaP-HPR cells, not in LNCaP, confirming that resistant cells were much less affected by exogenous oxidative stress. Unlike LNCaP, LNCaP-HPR cells were less sensitive to Cabazitaxel, as closer to the response of C4-2 mCRPC cells, indicating that redox adaptation decreased Cabazitaxel response. This is the first evaluated association between redox adaptation and poor Cabazitaxel response, suggesting that in vitro Cabazitaxel efficiency is affected by PC cells' endogenous oxidative stress tolerance. This article is protected by copyright. All rights reserved.

Applications of Plasma-Activated Water in Dentistry: A Review

The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma–liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma–liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases.

Host DNA repair response to oxidative damage is modulated by Trypanosoma cruzi in a strain-dependent manner

The conservation of genomic integrity and stability is essential for cell survival. DNA Damage Responses (DDRs) are considered of paramount importance for all living beings and involve mechanisms of cell cycle regulation and damage-specific DNA repair pathways. Hydrogen peroxide (H₂O₂) is a compound that, in supraphysiological concentrations, damages biomolecules including the DNA, causing base modifications and strand breaks. There is evidence that Trypanosoma cruzi, the protozoan that causes Chagas disease, interferes in the host cell's DNA metabolism. In order to investigate the influence of T. cruzi infection over the host cell capacity to withstand and repair DNA damage, we analyzed L6 cells infected with Berenice, and Colombiana T. cruzi strains according to their viability, proliferation, morphology, DNA degradation, expression of DNA repair, and cell cycle genes following H₂O₂ treatment. It was noted that T. cruzi infection might act as either a stressor or a protective element of host DNA, depending on the strain and H₂O₂ concentration. Cells infected with Berenice strain and treated with 0.8 mM H₂O₂ presented a reduced DNA damage response intensity (e.g., BER and HR). Infection with T. cruzi Colombiana prevented the activation of DNA repair pathways in response to 0.8mM and 1.6mM H₂O₂ (NER and MMR). Nevertheless, since cellular viability was not significantly compromised in Colombiana-infected cells following the oxidative insult, it is possible that the parasite directly influenced the host DNA repair machinery. Our results support the notion that T. cruzi is able to modulate the host cell DNA metabolism in a strain-dependent manner, an event which can be explored in future drug development strategies.

Oxidative Stress Induced Cell Cycle Arrest: Potential Role of PRX-2 and GSTP-1 as Therapeutic Targets in Hepatocellular Carcinoma

BACKGROUND

The increasing incidence and mortality rate of HCC is a major concern, especially for developing countries of the world. Hence, extensive research is being carried out in order to explore new approaches for developing successful therapeutic strategies for HCC. The controversial role of oxidative stress in the prognosis and treatment of various diseases such as cancer has become the area of great interest and intrigue for many scientists throughout the world.

OBJECTIVE

We aim to investigate the role of induced oxidative stress on the suppression of HCC Huh-7 cancerous cells as therapeutic approach.

METHODS

Induction of oxidative stress via H2O2 treatment produced cell cytotoxicity in a dose dependent manner and also led to the over expression of GSTP-1 and PRX-2. The expression of GSTP-1 and PRX-2 was compared in HCC Huh-7 treated, untreated cells and normal hepatocytes using immunocytochemistry. Furthermore, the effects of oxidative stress on cell cycle arrest were also studied through flow cytometry.

RESULTS

Our study demonstrated the inhibition of cancer cell proliferation as a result of H2O2 induction by arresting the cell cycle at G2 phase.

CONCLUSION

The induction of oxidative stress could be a potential therapeutic approach for treating HCC in the future. GSTP-1 and PRX-2 can serve as substantial therapeutic targets for the treatment of HCC.

Antioxidant Properties of Hydrogen Gas Attenuates Oxidative Stress in Airway Epithelial Cells

Oxidative stress plays a crucial role in the development of airway diseases. Recently, hydrogen (H₂) gas has been explored for its antioxidant properties. This study investigated the role of H₂ gas in oxidative stress-induced alveolar and bronchial airway injury, where A549 and NCI-H292 cells were stimulated with hydrogen peroxide (H₂O₂) and lipopolysaccharide (LPS) in vitro. Results show that time-dependent administration of 2% H₂ gas recovered the cells from oxidative stress. Various indicators including reactive oxygen species (ROS), nitric oxide (NO), antioxidant enzymes (catalase, glutathione peroxidase), intracellular calcium, and mitogen-activated protein kinase (MAPK) signaling pathway were examined to analyze the redox profile. The viability of A549 and NCI-H292 cells and the activity of antioxidant enzymes were reduced following induction by H₂O₂ and LPS but were later recovered using H₂ gas. Additionally, the levels of oxidative stress markers, including ROS and NO, were elevated upon induction but were attenuated after treatment with H₂ gas. Furthermore, H₂ gas suppressed oxidative stress-induced MAPK activation and maintained calcium homeostasis. This study suggests that H₂ gas can rescue airway epithelial cells from H₂O₂ and LPS-induced oxidative stress and may be a potential intervention for airway diseases.

Oxidative Stress Enhances Autophagy-Mediated Death Of Stem Cells Through Erk1/2 Signaling Pathway - Implications For Neurotransplantations

Stem cell therapies are becoming increasingly popular solutions for neurological disorders. However, there is a lower survival rate of these cells after transplantation. Oxidative stress is linked to brain damage, and it may also impact transplanted stem cells. To better understand how transplanted cells respond to oxidative stress, the current study used H₂O₂. We briefly illustrated that exogenous H₂O₂ treatment exaggerated oxidative stress in the human dental pulp and mesenchymal stem cells. 2',7'-Dichlorofluorescin diacetate (DCFDA), MitoSOX confirms the reactive oxygen species (ROS) involvement, which was remarkably subsided by the ROS inhibitors. The findings showed that H₂O₂ activates autophagy by enhancing pro-autophagic proteins, Beclin1 and Atg7. Increased LC3II/I expression (which co-localized with lysosomal proteins, LAMP1 and Cathepsin B) showed that H₂O₂ treatment promoted autophagolysosome formation. In the results, both Beclin1 and Atg7 were observed co-localized in mitochondria, indicating their involvement in mitophagy. The evaluation of Erk1/2 in the presence and absence of Na-Pyruvate, PEG-Catalase, and PD98059 established ROS-Erk1/2 participation in autophagy regulation. Further, these findings showed a link between apoptosis and autophagy. The results conclude that H₂O₂ acts as a stressor, promoting autophagy and mitophagy in stem cells under oxidative stress. The current study may help understand better cell survival and death approaches for transplanted cells in various neurological diseases. The current study uses human Dental Pulp and Mesenchymal Stem cells to demonstrate the importance of H₂O₂-driven autophagy in deciding the fate of these cells in an oxidative microenvironment. To summarise, we discovered that exogenous H₂O₂ treatment causes oxidative stress. Exogenous H₂O₂  treatment also increased ROS production, especially intracellular H₂O₂. H₂O₂ stimulated the ErK1/2 signaling pathway and autophagy. Erk1/2 was found to cause autophagy. Further, the function of mitophagy appeared to be an important factor in the H₂O₂-induced regulation of these two human stem cell types. In a nutshell, by engaging in autophagy nucleation, maturation, and terminal phase proteins, we elucidated the participation of autophagy in cell dysfunction and death.

Age and sex modify cellular proliferation responses to oxidative stress and glucocorticoid challenges in baboon cells

Aging is associated with progressive loss of cellular homeostasis resulting from intrinsic and extrinsic challenges. Lack of a carefully designed, well-characterized, precise, translational experimental model is a major limitation to understanding the cellular perturbations that characterize aging. Here, we tested the feasibility of primary fibroblasts isolated from nonhuman primates (baboons) as a model of cellular resilience in response to homeostatic challenge. Using a real-time live-cell imaging system, we precisely defined a protocol for testing effects of prooxidant compounds (e.g., hydrogen peroxide (H₂O₂), paraquat), thapsigargin, dexamethasone, and a low glucose environment on cell proliferation in fibroblasts derived from baboons across the life course (n = 11/sex). Linear regression analysis indicated that donor age significantly reduced the ability of cells to proliferate following exposure to H₂O₂ (50 and 100 µM) and paraquat (100 and 200 µM) challenges in cells from males (6.4-21.3 years; average lifespan 21 years) but not cells from females (4.3-15.9 years). Inhibitory effects of thapsigargin on cell proliferation were dependent on challenge duration (2 vs 24 h) and concentration (0.1 and 1 µM). Cells from older females (14.4-15.9 years) exhibited greater resilience to thapsigargin (1 µM; 24 h) and dexamethasone (500 µM) challenges than did those from younger females (4.3-6.7 years). The cell proliferation response to low glucose (1 mM) was reduced with age in both sexes. These data indicate that donor's chronological age and sex are important variables in determining fibroblast responses to metabolite and other challenges.

Immunotherapy Using Oxygenated Water and Tumor-Derived Exosomes Potentiates Antitumor Immune Response and Attenuates Malignancy Tendency in Mice Model of Breast Cancer

Breast cancer is one of the most common type of tumor and the leading cause of death in the world's female population. Various therapeutic approaches have been used to treat tumors but have not led to complete recovery and have even damaged normal cells in the body. Moreover, metastatic tumors such as breast cancer are much more resistant to treatment, and current treatments have not been very successful in treating them and remain a challenge. Therefore, new approaches should be applied to overcome this problem. Given the importance of hypoxia in tumor survival, we aimed to test the antitumor effects of oxygenated water to decrease hypoxia along with tumor-derived exosomes to target tumor. The purpose of administering oxygenated water and tumor exosomes was to reduce hypoxia and establish an effective immune response against tumor antigens, respectively. For this purpose, the breast cancer mice model was induced using the 4T1 cell line in Balb/c mice and treated with oxygenated water via an intratumoral (IT) and/or intraperitoneal (IP) route and/or exosome (TEX). Oxygenation via the IT+IP route was more efficient than oxygenation via the IT or IP route. The efficiency of oxygenation via the two routes along with TEX led to the best therapeutic outcome. Antitumor immune responses directed by TEX became optimized when systemic (IP) and local (IT) oxygenation was applied compared to administration of TEX alone. Results demonstrated a significant reduction in tumor size and the highest levels of IFN-γ and IL-17 and the lowest levels of IL-4 FoxP3, HIF-1α, VEGF, MMP-2, and MMP-9 in the IT+IP+TEX-treated group. Oxygenated water on the one hand could reduce tumor size, hypoxia, angiogenesis, and metastasis in the tumor microenvironment and on the other hand increases the effective immune response against the tumor systemically. This therapeutic approach is proposed as a new strategy for devising vaccines in a personalized approach.

Anti-Inflammatory and Anti-Oxidative Synergistic Effect of Vitamin D and Nutritional Complex on Retinal Pigment Epithelial and Endothelial Cell Lines against Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a multifactorial disease of the retina featured by dysfunction of retinal pigmented epithelial (RPE) and loss of photoreceptor cells under oxidative stress and inflammatory conditions. Vitamin D and antioxidants have beneficial effects against retinal degenerative diseases, such as AMD. We investigated the impact of associating vitamin D (ND) with a nutritional antioxidant complex (Nutrof Total^®; N) on oxidative stress and inflammation-like induced conditions by H₂O₂ and LPS, respectively, in human retinal epithelial (ARPE-19) and human retinal endothelial (HREC) cells. Application of either N or ND treatments to H₂O₂-induced media in ARPE-19 cells counteracted late apoptosis, attenuated oxidative DNA damage, and increased cell proliferation. Significant reduction in the expression levels of MCP1, IL-8, and IL6 cytokines was observed following application of either N or ND treatments under LPS-induced conditions in ARPE-19 cells and in MCP-1 and IL12p70 cytokine levels in HREC cells. ND and not N revealed significant downregulation of IFNγ in ARPE-19 cells, and of IL-6 and IL-18 in HREC cells. In conclusion, adding vitamin D to Nutrof Total^® protects in a synergistic way against oxidative and inflammatory stress-induced conditions in retinal epithelial and endothelial cells.

Val16A SOD2 Polymorphism Promotes Epithelial-Mesenchymal Transition Antagonized by Muscadine Grape Skin Extract in Prostate Cancer Cells

Epithelial–mesenchymal transition (EMT), a key event in cancer metastasis, allows polarized epithelial cells to assume mesenchymal morphologies, enhancing invasiveness and migration, and can be induced by reactive oxygen species (ROS). Val16A (Ala) SOD2 polymorphism has been associated with increased prostate cancer (PCa) risk. We hypothesized that SOD2 Ala single nucleotide polymorphism (SNP) may promote EMT. We analyzed SOD2 expression and genotype in various prostate cell lines. Stable overexpression of Ala-SOD2 or Val-SOD2 allele was performed in Lymph Node Carcinoma of the Prostate (LNCaP) cells followed by analysis of intracellular ROS and EMT marker protein expression. Treatments were performed with muscadine grape skin extract (MSKE) antioxidant, with or without addition of H₂O₂ to provide further oxidative stress. Furthermore, MTS cell proliferation, cell migration, and apoptosis assays were completed. The results showed that SOD2 expression did not correlate with tumor aggressiveness nor SOD2 genotype. We demonstrated that the Ala-SOD2 allele was associated with marked induction of EMT indicated by higher Snail and vimentin, lower E-cadherin, and increased cell migration, when compared to Val-SOD2 allele or Neo control cells. Ala-SOD2 SNP cells exhibited increased levels of total ROS and superoxide and were more sensitive to co-treatment with H₂O₂ and MSKE, which led to reduced cell growth and increased apoptosis. Additionally, MSKE inhibited Ala-SOD2 SNP-mediated EMT. Our data indicates that treatment with a combination of H₂O₂-generative drugs, such as certain chemotherapeutics and antioxidants such as MSKE that targets superoxide, hold promising therapeutic potential to halt PCa progression in the future.

Design, synthesis, biological evaluation of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehydes as non-purine xanthine oxidase inhibitors: Tracing the anticancer mechanism via xanthine oxidase inhibition

Xanthine oxidase (XO) has been primarily targeted for the development of anti-hyperuriciemic /anti-gout agents as it catalyzes the conversion of xanthine and hypoxanthine into uric acid. XO overexpression in various cancer is very well correlated due to reactive oxygen species (ROS) production and metabolic activation of carcinogenic substances during the catalysis. Herein, we report the design and synthesis of a series of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehyde derivatives (2a-2x) as xanthine oxidase inhibitors (XOIs). A docking model was developed for the prediction of XO inhibitory activity of our novel compounds. Furthermore, our compounds anticancer activity results in low XO expression and XO-harboring cancer cells both in 2D and 3D-culture models are presented and discussed. Among the array of synthesized compounds, 2b and 2m emerged as potent XO inhibitors having IC₅₀ values of 9.32 ± 0.45 µM and 10.03 ± 0.43 µM, respectively. Both compounds induced apoptosis, halted the cell cycle progression at the G1 phase, elevated ROS levels, altered mitochondrial membrane potential, and inhibited antioxidant enzymes. The levels of miRNA and expression of redox sensors in cells were also altered due to increase oxidative stress induced by our compounds. Compounds 2b and 2m hold a great promise for further development of XOIs for the treatment of XO-harboring tumors.

Breaking the Intracellular Redox Balance with Diselenium Nanoparticles for Maximizing Chemotherapy Efficacy on Patient-Derived Xenograft Models

Excessive oxidative stress in cancer cells can induce cancer cell death. Anticancer activity and drug resistance of chemotherapy are closely related to the redox state of tumor cells. Herein, five lipophilic Pt(IV) prodrugs were synthesized on the basis of the most widely used anticancer drug cisplatin, whose anticancer efficacy and drug resistance are closely related to the intracellular redox state. Subsequently, a series of cisplatin-sensitive and drug-resistant cell lines as well as three patient-derived primary ovarian cancer cells have been selected to screen those prodrugs. To verify if the disruption of redox balance can be combined with these Pt(IV) prodrugs, we then synthesized a polymer with a diselenium bond in the main chain for encapsulating the most effective prodrug to form nanoparticles (NP(Se)s). NP(Se)s can efficiently break the redox balance via simultaneously depleting GSH and augmenting ROS, thereby achieving a synergistic effect with cisplatin. In addition, genome-wide analysis via RNA-seq was employed to provide a comprehensive understanding of the changes in transcriptome and the alterations in redox-related pathways in cells treated with NP(Se)s and cisplatin. Thereafter, patient-derived xenograft models of hepatic carcinoma (PDX^HCC) and multidrug-resistant lung cancer (PDX^MDR) were established to evaluate the therapeutic effect of NP(Se)s, and a significant antitumor effect was achieved on both models with NP(Se)s. Overall, this study provides a promising strategy to break the redox balance for maximizing the efficacy of platinum-based cancer therapy.

Therapeutic Potential of Reactive Oxygen Species: State of the Art and Recent Advances

In the last decade, several studies have proven that when at low concentration reactive oxygen species (ROS) show an adaptive beneficial effect and posited the idea that they can be utilized as inexpensive and convenient inducers of tissue regeneration. On the other hand, the recent discovery that cancer cells are more sensitive to oxidative damage paved the way for their use in the selective killing of tumor cells, and sensors to monitor ROS production during cancer treatment are under extensive investigation. Nevertheless, although ROS-activated signaling pathways are well established, less is known about the mechanisms underlying the switch from an anabolic to a cytotoxic response. Furthermore, a high variability in biological response is observed between different modalities of administration, cell types, donor ages, eventual concomitant diseases, and external microenvironment. On the other hand, available preclinical studies are scarce, whereas the quest for the most suitable systems for in vivo delivery is still elusive. Furthermore, new strategies to control the temporal pattern of ROS release need to be developed, if considering their tumorigenic potential. This review initially discusses ROS mechanisms of action and their potential application in stem cell biology, tissue engineering, and cancer therapy. It then outlines the state of art of ROS-based drugs and identifies challenges faced in translating ROS research into clinical practice.

Recent Research on Methods to Improve Tumor Hypoxia Environment

Cancer is a major disease burden worldwide. In recent years, in addition to surgical resection, radiotherapy and chemotherapy are recognized as the most effective methods for treating solid tumors. These methods have been introduced to treat tumors of different origins and stages clinically. However, due to insufficient blood flow and oxygen (O2) supply in solid tumors, hypoxia is caused, leading to decreased sensitivity of tumor cells and poor therapeutic effects. In addition, hypoxia will also lead to resistance to most anticancer drugs, accelerate malignant progress, and increase metastasis. In solid tumors, adequate O2 supply and adequate delivery of anticancer drugs are essential to improve radiotherapy and chemotherapy sensitivity. In recent decades, the researches on relieving tumor hypoxia have attracted researchers' extensive attention and achieved good results. However, as far as we know, there is no detailed review of the researches on alleviating tumor hypoxia. Therefore, in this contribution, we hope to give an overview of the researches on methods to improve tumor hypoxia environment and summarize their effect and application in tumor therapy, to provide a methodological reference for the research and development of new antitumor agents.

Similarities between the effect of SARS-CoV-2 and HCV on the cellular level, and the possible role of ion channels in COVID19 progression: a review of potential targets for diagnosis and treatment

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has prompted an urgent need to identify effective medicines for the prevention and treatment of the disease. A comparative analysis between SARS-CoV-2 and Hepatitis C Virus (HCV) can expand the available knowledge regarding the virology and potential drug targets against these viruses. Interestingly, comparing HCV with SARS-CoV-2 reveals major similarities between them, ranging from the ion channels that are utilized, to the symptoms that are exhibited by patients. Via this comparative analysis, and from what is known about HCV, the most promising treatments for COVID-19 can focus on the reduction of viral load, treatment of pulmonary system damages, and reduction of inflammation. In particular, the drugs that show most potential in this regard include ritonavir, a combination of peg-IFN, and lumacaftor-ivacaftor. This review anaylses SARS-CoV-2 from the perspective of the role of ion homeostasis and channels in viral pathomechanism. We also highlight other novel treatment approaches that can be used for both treatment and prevention of COVID-19. The relevance of this review is to offer high-quality evidence that can be used as the basis for the identification of potential solutions to the COVID-19 pandemic.

Screening of Health-Associated Oral Bacteria for Anticancer Properties in vitro

While extensive literature exists about the role of oral bacterial pathogens like Porphyromonas gingivalis and Fusobacterium nucleatum in oral squamous cell carcinoma (OSCC), the role of health-associated species has been largely unexplored. In this study, we assessed the effect of Streptococcus mitis, Rothia mucilaginosa, Neisseria flavescens, Haemophilus parainfluenzae, Lautropia mirabilis, and Veillonella parvula on proliferation and expression of marker genes (IL-6, TNF-α, MMP3, CD36, CCD1, and NANOG) in OSCC cell lines CAL27, SCC25, and SCC4. Porphyromonas gingivalis was included as a pathogenic control. Both bacterial lysates (3 concentrations) and live cells (3 MOIs) were tested. S. mitis, H. parainfluenzae, and N. flavescens resulted in substantial, dose-dependent reduction of proliferation, which was found to be mediated by H₂O₂ for the former and intracellular infection in the latter two species. However, only H. parainfluenzae showed differential antiproliferative effect against the cancer cell lines vs. the normal control (TIGKs). In the gene expression assays, the health-associated species mostly downregulated CD36, a gene that plays an important role in tumor growth and metastasis, while P. gingivalis upregulated it. IL6 and TNF expression, on the other hand, was upregulated by almost all species, particularly the Gram-negatives including P. gingivalis. The effect on other genes was less evident and varied significantly by cell line. This exploratory study is the first insight into how health-associated bacteria may interact with OSCC. Further studies to explore whether the observed effects may have implications for the prevention or treatment of oral cancer are warranted.

Hepatoprotective properties of red betel (Piper crocatum Ruiz and Pav) leaves extract towards H2O2-induced HepG2 cells via anti-inflammatory, antinecrotic, antioxidant potency

BACKGROUND

Prolonged exposure of free radicals, or known as reactive oxygen species (ROS), in hepatic cells may cause oxidative stress. Without proper treatment, it can induce liver injury and fatal hepatic disease, including cirrhosis. Red betel (Piper crocatum Ruiz and Pav) is one of Indonesia's medicinal plants that has been known to exhibit antioxidant, anti-inflammatory activities. This study aims to determine hepatoprotective effect of red betel leaves extract (RBLE) towards liver injury.

METHOD

Hydrogen peroxide-induced HepG2 cells were used as liver injury model·H2O2-induced HepG2 cells were treated with 25 µg/mL and 100 µg/mL RBLE. Several parameters were observed, including TNF-α level through ELISA; necrotic, apoptotic, dead, live cells; and ROS level through flow cytometry analysis; and GPX gene expression through qPCR.

RESULT

The study showed that treatment with RBLE were able to decrease TNF-α level; necrotic and death cells percentage; as well as ROS level. On the other hand, it were able to increase apoptotic and live cells percentage; as well as GPX gene expression. Low concentration (25 µg/mL) of RBLE treatment exhibited stronger anti-inflammatory activity as it was resulted in the lower TNF-α level and were able to switched hepatic cell death pathway from necrosis to apoptosis as shown by the shifted of apoptotic cells and necrotic cells percentage. This lead to lower death cells and ultimately improve live cells percentage. Meanwhile high concentration of RBLE (100 µg/mL) exhibited stronger antioxidant properties as indicated by lower ROS level and higher GPX gene expression.

CONCLUSION

Overall, this study was able to demonstrate hepatoprotective effect of RBLE towards liver injury model through its anti-inflammatory and antioxidant activities.

Cold Atmospheric Plasma Treatment for Pancreatic Cancer-The Importance of Pancreatic Stellate Cells

Simple Summary

This review aims to highlight the potential of cold plasma, the fourth state of matter, as anti-cancer treatment for pancreatic cancer, and the importance of pancreatic stellate cells in the response to this treatment. Currently, a significant lack of basic research on cold plasma considering both pancreatic cancer and stellate cells exists. However, co-cultures of these populations can be advantageous, as they resemble the cell-to-cell interactions occurring in a tumor in response to therapy. Even more, these studies should be performed prior to clinical trials of cold plasma to avoid unforeseen responses to treatment. This review article provides a framework for future research of cold plasma therapies for pancreatic cancer, considering the critical role of pancreatic stellate cells in the disease and treatment outcome.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with low five-year survival rates of 8% by conventional treatment methods, e.g., chemotherapy, radiotherapy, and surgery. PDAC shows high resistance towards chemo- and radiotherapy and only 15–20% of all patients can have surgery. This disease is predicted to become the third global leading cause of cancer death due to its significant rise in incidence. Therefore, the development of an alternative or combinational method is necessary to improve current approaches. Cold atmospheric plasma (CAP) treatments could offer multiple advantages to this emerging situation. The plasma-derived reactive species can induce oxidative damage and a cascade of intracellular signaling pathways, which could lead to cell death. Previous reports have shown that CAP treatment also influences cells in the tumor microenvironment, such as the pancreatic stellate cells (PSCs). These PSCs, when activated, play a crucial role in the propagation, growth and survival of PDAC tumors. However, the effect of CAP on PSCs is not yet fully understood. This review focuses on the application of CAP for PDAC treatment and the importance of PSCs in the response to treatment.

Novel Therapeutic Approaches of Ion Channels and Transporters in Cancer

The expression and function of many ion channels and transporters in cancer cells display major differences in comparison to those from healthy cells. These differences provide the cancer cells with advantages for tumor development. Accordingly, targeting ion channels and transporters have beneficial anticancer effects including inhibition of cancer cell proliferation, migration, invasion, metastasis, tumor vascularization, and chemotherapy resistance, as well as promoting apoptosis. Some of the molecular mechanisms associating ion channels and transporters with cancer include the participation of oxidative stress, immune response, metabolic pathways, drug synergism, as well as noncanonical functions of ion channels. This diversity of mechanisms offers an exciting possibility to suggest novel and more effective therapeutic approaches to fight cancer. Here, we review and discuss most of the current knowledge suggesting novel therapeutic approaches for cancer therapy targeting ion channels and transporters. The role and regulation of ion channels and transporters in cancer provide a plethora of exceptional opportunities in drug design, as well as novel and promising therapeutic approaches that may be used for the benefit of cancer patients.

Therapeutic effect of hydrogen peroxide via altered expression of glutathione S-transferase and peroxiredoxin-2 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) has a high incidence and mortality that epitomizes one of the prominent causes of cancer-related death globally. Novel therapeutic approaches are therefore required. Reactive oxygen species (ROS) are necessary for maintaining cell cycle. Although ROS is involved in HCC progression, hydrogen peroxide (H₂O₂) has anti-proliferative effect on HCC.

METHOD

HCC Huh-7 cells were cultured and incubated with various concentrations of H₂O₂. Paraoxonase activity, levels of malondialdehyde, glutathione and protein oxidation were measured in treated and untreated Huh-7 cells. Furthermore, untreated and treated Huh-7 cells were subjected to two dimensional gel electrophoresis and identified protein spots which were differentially expressed by LC-MS/MS analysis. qRT-PCR was performed to validate the identified proteins.

RESULTS

H₂O₂ depleted glutathione (GSH) with the concomitant up-regulation of GSTP1 and Prx2. H₂O₂ also increased malondialdehyde and protein oxidation, decreased the activity of paraoxonase in Huh-7 cells.

CONCLUSION

H₂O₂ could be used as a novel therapeutic agent that might be beneficial in inducing cell cytotoxicity and hence suppress HCC proliferation.

Lung cancer increases H2O2 concentration in the exhaled breath condensate, extent of mtDNA damage, and mtDNA copy number in buccal mucosa

We have shown that the H2O2 concentration in exhaled breath condensate (EBC) in lung cancer patients increases significantly compared to the EBC of healthy people and revealed the correlation between the H2O2 level in the EBC and amount of mtDNA damage in buccal mucosa cells. The H2O2 hyper-production may trigger mitochondrial biogenesis, thereby resulting in an increase in mtDNA copy number. However, we did not observe a significant difference in the studied parameters between smokers and non-smokers. Overall, our data suggest that H2O2 concentration in the EBC, the extent of mtDNA damage, and mtDNA copy number in buccal mucosa could be potential as an early diagnostic marker of lung cancer.

Self-Propelling Targeted Magneto-Nanobots for Deep Tumor Penetration and pH-Responsive Intracellular Drug Delivery

Self-propelling magnetic nanorobots capable of intrinsic-navigation in biological fluids with enhanced pharmacokinetics and deeper tissue penetration implicates promising strategy in targeted cancer therapy. Here, multi-component magnetic nanobot designed by chemically conjugating magnetic Fe3O4 nanoparticles (NPs), anti-epithelial cell adhesion molecule antibody (anti-EpCAM mAb) to multi-walled carbon nanotubes (CNT) loaded with an anticancer drug, doxorubicin hydrochloride (DOX) is reported. Autonomous propulsion of the nanobots and their external magnetic guidance is enabled by enriching Fe3O4 NPs with dual catalytic-magnetic functionality. The nanobots propel at high velocities even in complex biological fluids. In addition, the nanobots preferably release DOX in the intracellular lysosomal compartment of human colorectal carcinoma (HCT116) cells by the opening of Fe3O4 NP gate. Further, nanobot reduce ex vivo HCT116 tumor spheroids more efficiently than free DOX. The multicomponent nanobot's design represents a more pronounced method in targeting tumors with self-assisted anticancer drug delivery for 'far-reaching' sites in treating cancers.

Regenerative engineered vascularized bone mediated by calcium peroxide

One of the main challenges hindering the clinical translation of bone tissue engineering scaffolds is the lack of establishment of functional vasculature. Insufficient vascularization and poor oxygen supply limit cell survival within the constructs resulting in poor osseointegration with the host tissue and eventually leading to inadequate bone regeneration. Inspired by cues from developmental biology, we regenerative engineered a composite matrix by incorporating calcium peroxide (CaO₂ ) into poly(lactide-co-glycolide) (PLGA) microsphere-based matrices and sought to assess whether the delivery of the byproducts of CaO₂ decomposition, namely O₂ , Ca²⁺ , and H₂ O₂ could enhance the regeneration of vascularized bone tissue. The composite microspheres were successfully fabricated via the oil-in-water emulsion method. The presence and encapsulation of CaO₂ was confirmed using scanning electron microscopy, energy dispersive x-ray spectroscopy, thermogravimetric analysis, and X-ray powder diffraction. The microspheres were further heat sintered into three-dimensional porous scaffolds and characterized for their degradation and release of byproducts. The in vitro cytocompatibility of the matrices and their ability to support osteogenic differentiation was confirmed using human adipose-derived stem cells. Lastly, an in vivo study was performed in a mouse critical-sized calvarial defect model to evaluate the capacity of these matrices in supporting vascularized bone regeneration. Results demonstrated that the presence of CaO₂ increased cellularization and biological activity throughout the matrices. There was greater migration of host cells to the interior of the matrices and greater survival and persistence of donor cells after 8 weeks, which in synergy with the composite matrices led to enhanced vascularized bone regeneration.

Oncolytic Nanoreactors Producing Hydrogen Peroxide for Oxidative Cancer Therapy

In situ generation of anticancer agents at the place of the disease is a new paradigm for cancer therapy. The production of highly potent drugs by nanoreactors through a facile synthesis pathway is demanded. We report an oncolytic nanoreactor platform loaded with the enzyme glucose oxidase (GOX) to produce hydrogen peroxide. For the first time, we realized a core-shell structure with encapsulated GOX under mild synthetic conditions, which ensured high remaining activity of GOX inside of the nanoreactor. Moreover, the nanoreactor protected the loaded GOX from proteolysis and contributed to increased thermal stability of the enzyme. The nanoreactors were effectively taken up into different cancer cells, in which they produced hydrogen peroxide by consuming intracellular glucose and oxygen, thereby leading to effective death of the cancer cells. In summary, our robust nanoreactors are a promising platform for effective anticancer therapy and sustained enzyme utilization.

Targeting the unfolded protein response in head and neck and oral cavity cancers

Many FDA-approved anti-cancer therapies, targeted toward a wide array of molecular targets and signaling networks, have been demonstrated to activate the unfolded protein response (UPR). Despite a critical role for UPR signaling in the apoptotic execution of cancer cells by many of these compounds, the authors are currently unaware of any instance whereby a cancer drug was developed with the UPR as the intended target. With the essential role of the UPR as a driving force in the genesis and maintenance of the malignant phenotype, a great number of pre-clinical studies have surged into the medical literature describing the ability of dozens of compounds to induce UPR signaling in a myriad of cancer models. The focus of the current work is to review the literature and explore the role of the UPR as a mediator of chemotherapy-induced cell death in squamous cell carcinomas of the head and neck (HNSCC) and oral cavity (OCSCC), with an emphasis on preclinical studies.

Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines

Background

Tumourigenic cells modify metabolic pathways in order to facilitate increased proliferation and cell survival resulting in glucose- and glutamine addiction. Previous research indicated that glutamine deprivation resulted in potential differential activity targeting tumourigenic cells more prominently. This is ascribed to tumourigenic cells utilising increased glutamine quantities for enhanced glycolysis- and glutaminolysis. In this study, the effects exerted by glutamine deprivation on reactive oxygen species (ROS) production, mitochondrial membrane potential, cell proliferation and cell death in breast tumourigenic cell lines (MCF-7, MDA-MB-231, BT-20) and a non-tumourigenic breast cell line (MCF-10A) were investigated.

Results

Spectrophotometry demonstrated that glutamine deprivation resulted in decreased cell growth in a time-dependent manner. MCF-7 cell growth was decreased to 61% after 96 h of glutamine deprivation; MDA-MB-231 cell growth was decreased to 78% cell growth after 96 h of glutamine deprivation, MCF-10A cell growth was decreased 89% after 96 h of glutamine deprivation and BT-20 cell growth decreased to 86% after 24 h of glutamine deprivation and remained unchanged until 96 h of glutamine deprivation. Glutamine deprivation resulted in oxidative stress where superoxide levels were significantly elevated after 96 h in the MCF-7- and MDA-MB-231 cell lines. Time-dependent production of hydrogen peroxide was accompanied by aberrant mitochondrial membrane potential. The effects of ROS and mitochondrial membrane potential were more prominently observed in the MCF-7 cell line when compared to the MDA-MB-231-, MCF-10A- and BT-20 cell lines. Cell cycle progression revealed that glutamine deprivation resulted in a significant increase in the S-phase after 72 h of glutamine deprivation in the MCF-7 cell line. Apoptosis induction resulted in a decrease in viable cells in all cell lines following glutamine deprivation. In the MCF-7 cells, 87.61% of viable cells were present after 24 h of glutamine deprivation.

Conclusion

This study demonstrates that glutamine deprivation resulted in decreased cell proliferation, time-dependent- and cell line-dependent ROS generation, aberrant mitochondrial membrane potential and disrupted cell cycle progression. In addition, the estrogen receptor positive MCF-7 cell line was more prominently affected. This study contributes to knowledge regarding the sensitivity of breast cancer cells and non-tumorigenic cells to glutamine deprivation.

Electronic supplementary material

The online version of this article (10.1186/s40659-019-0224-9) contains supplementary material, which is available to authorized users.

Cell damaging by irradiating non-thermal plasma to the water: Mathematical modeling of chemical processes

Recently non-thermal plasma (NTP) is applied for many therapeutic applications. By NTP irradiating to the tissues or cell-lines, the water molecules (H₂O) would be also activated leading to generate hydrogen peroxide (H₂O₂). By irradiating plasma to bio-solution, its main output including vacuum UV to UV causes the photolysis of H₂O leading to generate hydroxyl (OH) molecules in couple forms with ability to convert to H₂O₂. Additionally, other plasma's output the oxygen atoms could also penetrate under the liquid's surface and react with H₂O to generate H₂O₂. In NTP applications for killing unwanted-cells of microorganisms (e.g. sterilization) or cancerous tissues, the H₂O₂ molecule is the main reactive species for cell death via inducing DNA damage in mammalian cells. In this paper we proposed a mathematical model for NTP application describing the formation of hydroxyls in the bio solution and other subsequent reactions leading to DNA damage in vitro. The instant concentrations of the OH and H₂O₂, the main species for DNA oxidation were obtained and investigated in this simulation. In order to validate the model, the cellular response to NTP stimulation was compared with some experimental findings from viewpoint of DNA damage to show the significant consistency.

Plasma-activation of tap water using DBD for agronomy applications: Identification and quantification of long lifetime chemical species and production/consumption mechanisms

Cold atmospheric plasmas are weakly ionized gases that can be generated in ambient air. They produce energetic species (e.g. electrons, metastables) as well as reactive oxygen species, reactive nitrogen species, UV radiations and local electric field. Their interaction with a liquid such as tap water can hence change its chemical composition. The resulting "plasma-activated liquid" can meet many applications, including medicine and agriculture. Consequently, a complete experimental set of analytical techniques dedicated to the characterization of long lifetime chemical species has been implemented to characterize tap water treated using cold atmospheric plasma process and intended to agronomy applications. For that purpose, colorimetry and acid titrations are performed, considering acid-base equilibria, pH and temperature variations induced during plasma activation. 16 species are quantified and monitored: hydroxide and hydronium ions, ammonia and ammonium ions, orthophosphates, carbonate ions, nitrite and nitrate ions and hydrogen peroxide. The related consumption/production mechanisms are discussed. In parallel, a chemical model of electrical conductivity based on Kohlrausch's law has been developed to simulate the electrical conductivity of the plasma-activated tap water (PATW). Comparing its predictions with experimental measurements leads to a narrow fitting, hence supporting the self-sufficiency of the experimental set, I.e. the fact that all long lifetime radicals of interest present in PATW are characterized. Finally, to evaluate the potential of cold atmospheric plasmas for agriculture applications, tap water has been daily plasma-treated to irrigate lentils seeds. Then, seedlings lengths have been measured and compared with untreated tap water, showing an increase as high as 34.0% and 128.4% after 3 days and 6 days of activation respectively. The interaction mechanisms between plasma and tap water are discussed as well as their positive synergy on agronomic results.

Cytotoxicity Study of Cyclopentapeptide Analogues of Marine Natural Product Galaxamide towards Human Breast Cancer Cells

Herein, we report the cytotoxicity of cyclopentapeptide analogues of marine natural product galaxamide towards breast carcinoma cells and the underlying mechanisms. We examined the effect of the novel galaxamide analogues on cancer cell proliferation by MTT assay and also further examined the most active compound for morphological changes using Hoechst33342 staining technique, induction of apoptosis, cell cycle phases, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) generation using flow cytometry in human breast cancer MCF-7 cells in vitro. Galaxamide and its analogues effectively induced toxicity in human hepatocellular carcinoma HepG2, human breast carcinoma MCF-7, human epitheloid cervix carcinoma HeLa, and human breast carcinoma MB-MDA-231 cell lines. Amongst them, compound 3 exhibited excellent toxicity towards MCF-7 cells. This galaxamide analogue significantly induced apoptosis in a dose-dependent manner in MCF-7 cells involves cell cycle arrest in the G1 phase, a reduction of MMP, and a marked increase in generation of ROS. Particularly, compound 3 of galaxamide analogues might be a potential candidate for the treatment of breast cancer.

Polymer Prodrug-Based Nanoreactors Activated by Tumor Acidity for Orchestrated Oxidation/Chemotherapy

Therapeutic nanoreactors have been proposed to treat cancers through in situ transformation of low-toxicity prodrugs into toxic therapeutics in the body. However, the in vivo applications are limited by low tissue-specificity and different tissue distributions between sequentially injected nanoreactors and prodrugs. Herein, we construct a block copolymer prodrug-based polymersome nanoreactor that can achieve novel orchestrated oxidation/chemotherapy of cancer via specific activation at tumor sites. The block copolymers composed of poly(ethylene glycol) (PEG) and copolymerized monomers of camptothecin (CPT) and piperidine-modified methacrylate [P(CPTMA-co-PEMA)] were optimized to self-assemble into polymersomes in aqueous solution for encapsulation of glucose oxidase (GOD) to obtain GOD-loaded polymersome nanoreactors (GOD@PCPT-NR). GOD@PCPT-NR maintained inactive in normal tissues upon systemic administration. After deposition in tumor tissues, tumor acidity-triggered protonation of PPEMA segments resulted in high permeability of the polymersome membranes and oxidation reaction of diffused glucose and O₂ under the catalysis of GOD. The activation of the reaction generated H₂O₂, improving the oxidative stress in tumors. Simultaneously, a high level of H₂O₂ further activated PCPTMA prodrugs, releasing active CPT drugs. High tumor oxidative stress and released CPT drugs synergistically killed cancer cells and suppressed tumor growth via oxidation/chemotherapy. Our study provides a new strategy for engineering therapeutic nanoreactors in an orchestrated fashion for cancer therapy.

UCP2 upregulation promotes PLCγ-1 signaling during skin cell transformation

Uncoupling protein 2 (UCP2), whose physiological role is to decrease mitochondrial membrane potential and reactive oxygen species (ROS) production, is often overexpressed in human cancers. UCP2 upregulation has recently been proposed as a novel survival mechanism for cancer cells. However, until now, how exactly UCP2 promotes tumorigenesis remains inconclusive. Based on a widely used skin cell transformation model, our data demonstrated that UCP2 differentially regulated ROS. UCP2 upregulation decreased superoxide whereas it increased hydrogen peroxide production with concomitant increase in the expression and activity of manganese superoxide dismutase (MnSOD), the primary mitochondrial antioxidant enzyme. Furthermore, hydrogen peroxide was responsible for induction of lipid peroxidation, and PLCγ-1 activation in UCP2 overexpressed cells. Additionally, PLCγ-1 activation enhanced skin cell transformation, and pharmacological, and siRNA mediated inhibition of PLCγ-1, markedly reduced colony formation, and 3D cell growth. Moreover, hydrogen peroxide scavenger, catalase, suppressed lipid peroxidation, and dampened PLCγ-1 activity. Taken together, our data suggest that (i) UCP2 is an important regulator of mitochondrial redox status and lipid signaling; (ii) hydrogen peroxide might mediate UCP2's tumor promoting activity; and (iii) pharmacological disruption of PLCγ-1 and/or hydrogen peroxide may have clinical utility for UCP2 overexpressed cancers.