Redox regulation in cancer: a double-edged sword with therapeutic potential

Fumonisin B1 protects against long-chained polyunsaturated fatty acid-induced cell death in HepG2 cells - implications for cancer promotion

Fumonisin B1 (FB1), a food-borne mycotoxin, is a cancer promoter in rodent liver and augments proliferation of initiated cells while inhibiting the growth of normal hepatocytes by disrupting lipid biosynthesis at various levels. HepG2 cancer cells exhibited resistance to FB1-induced toxic effects presumably due to their low content of polyunsaturated fatty acids (PUFA) even though FB1-typical lipid changes were observed, e.g. significantly increased phosphatidylethanolamine (PE), decreased sphingomyelin and cholesterol content, increased sphinganine (Sa) and sphinganine/sphingosine ratio, increased C18:1ω-9, decreased C20:4ω-6 content in PE and decreased C20:4ω-6_PC/PE ratio. Increasing PUFA content of HepG2 cells with phosphatidylcholine (PC) vesicles containing C20:4ω-6 (SAPC) or C22:6ω-3 (SDPC) disrupted cell survival, cellular redox status and induced oxidative stress and apoptosis. A partially protective effect of FB1 was evident in PUFA-enriched HepG2 cells which may be related to the FB1-induced reduction in oxidative stress and the disruption of key cell membrane constituents indicative of a resistant lipid phenotype. Interactions between different ω-6 and ω-3 PUFA, membrane constituents including cholesterol, and the glycerophospho- and sphingolipids and FB1 in this cell model provide further support for the resistant lipid phenotype and its role in the complex cellular effects underlying the cancer promoting potential of the fumonisins.

Demethoxymurrapanine, an indole-naphthoquinone alkaloid, inhibits the proliferation of oral cancer cells without major side effects on normal cells

Antioral cancer drugs need a greater antiproliferative impact on cancer than on normal cells. Demethoxymurrapanine (DEMU) inhibits proliferation in several cancer cells, but an in-depth investigation was necessary. This study evaluated the proliferation-modulating effects of DEMU, focusing on oral cancer and normal cells. DEMU (0, 2, 3, and 4 μg/mL) at 48 h treatments inhibited the proliferation of oral cancer cells (the cell viability (%) for Ca9-22 cells was 100.0 ± 2.2, 75.4 ± 5.6, 26.0 ± 3.8, and 15.4 ± 1.4, and for CAL 27 cells was 100.0 ± 9.4, 77.2 ± 5.9, 57.4 ± 10.7, and 27.1 ± 1.1) more strongly than that of normal cells (the cell viability (%) for S-G cells was 100.0 ± 6.6, 91.0 ± 4.6, 95.0 ± 2.6, and 95.8 ± 5.5), although this was blocked by the antioxidant N-acetylcysteine. The presence of oxidative stress was evidenced by the increase of reactive oxygen species and mitochondrial superoxide and the downregulation of the cellular antioxidant glutathione in oral cancer cells, but these changes were minor in normal cells. DEMU also caused greater induction of the subG1 phase, extrinsic and intrinsic apoptosis (annexin V and caspases 3, 8, and 9), and DNA damage (γH2AX and 8-hydroxy-2-deoxyguanosine) in oral cancer than in normal cells. N-acetylcysteine attenuated all these DEMU-induced changes. Together, these data demonstrate the preferential antiproliferative function of DEMU in oral cancer cells, with the preferential induction of oxidative stress, apoptosis, and DNA damage in these cancer cells, and low cytotoxicity toward normal cells.

Juglone-ascorbate treatment enhances reactive oxygen species mediated mitochondrial apoptosis in pancreatic cancer

BACKGROUND

Treatment of Pancreatic Cancer (PC) is challenging due to its aggressiveness and acquired resistance to conventional chemotherapy and radiotherapy. Therefore, the discovery of new therapeutic agents and strategies is essential. Juglone, a naphthoquinone, is a secondary metabolite produced naturally in walnut-type trees having allelopathic features in its native environment. Juglone was shown to prevent cell proliferation and induce ROS-mediated mitochondrial apoptosis. Ascorbate with both antioxidant and oxidant features, shows selective cytotoxicity in cancer cells.

METHODS AND RESULTS

In this study, we evaluated the anticancer effects of Juglone in combination with ascorbate in PANC-1 and BxPC-3 PC cells. The MTT assay was used to determine the IC50 dose of Juglone with 1 mM NaAscorbate (Jug-NaAsc). Subsequently, the cells were treated with 5, 10, 15 and 20 µM Jug-NaAsc for 24 h. Apoptotic effects were evaluated by analyzing the following genes using qPCR; proapoptotic Bax, antiapoptotic Bcl-2 related to the mitochondrial apoptotic pathway and apoptosis inhibitor Birc5 (Survivin). Immunofluorescence analysis was performed using Annexin V-FITC in PC cells. As an antioxidant enzyme, Trx2 protein levels were determined by a commercial ELISA test kit. Jug-NaAsc treatment decreased the expressions of antiapoptotic genes Bcl-2 and Birc5 while the apoptotic gene Bax expression increased at all doses. Additionally, a dose-dependently increase of apoptosis according to immunofluorescence analysis and the decreases of Trx2 enzyme levels at all treatments in both cell lines supported gene expression results.

CONCLUSION

Our results suggest that Juglone is a potential anticancer agent especially when combined with ascorbate.

Oxidative stress related effect of xenobiotics on eukaryotic model organism, Saccharomyces cerevisiae

Ecotoxicological assays have traditionally focused on the effects of chemicals at the individual level by exploiting mortality and reproduction as endpoints. Although these two parameters are ecologically relevant, they rarely provide information regarding the elemental toxic mechanisms. Obviously, the number of xenobiotics used has been rapidly increased. Thus, any established measurement that shortens the actual outcome and, simultaneously provides information about toxic mechanisms is desirable. This research focused on the study of oxidative stress response as a biomarker in the eukaryotic model organism, Saccharomyces cerevisiae. For this, yeast cells were exposed to a set of selected environmentally relevant chemicals via different approaches, including cellular diagnostics, gene expression analysis and chemo-genetic screening. The results demonstrated that at the cellular level, model organisms reacted to different chemicals in distinct manner. For each xenobiotic, the correlation between toxic response of molecular and cellular levels are presented. Namely, the expression of target genes after chemical exposure affected the cellular alteration as evidenced by an elevated level of superoxide dismutase and a reduced amount of glutathione. Furthermore, the results derived from chemo-genetic screening, in which mutants lacking of gene of interest were employed, exhibited more susceptibility to test chemicals in comparison to the wildtype. The response of oxidative stress upon chemical exposure in budding yeast from this study is potentially useful for an establishment of a proper bio-test system which can eventually be linked to adverse effects at an individual level in higher eukaryotes.

Corrigendum: Immunomodulatory function and anti-tumor mechanism of natural polysaccharides: a review

[This corrects the article DOI: 10.3389/fimmu.2023.1147641.].

Antioxidant peptides, the guardian of life from oxidative stress

Reactive oxygen species (ROS) are produced during oxidative metabolism in aerobic organisms. Under normal conditions, ROS production and elimination are in a relatively balanced state. However, under internal or external environmental stress, such as high glucose levels or UV radiation, ROS production can increase significantly, leading to oxidative stress. Excess ROS production not only damages biomolecules but is also closely associated with the pathogenesis of many diseases, such as skin photoaging, diabetes, and cancer. Antioxidant peptides (AOPs) are naturally occurring or artificially designed peptides that can reduce the levels of ROS and other pro-oxidants, thus showing great potential in the treatment of oxidative stress-related diseases. In this review, we discussed ROS production and its role in inducing oxidative stress-related diseases in humans. Additionally, we discussed the sources, mechanism of action, and evaluation methods of AOPs and provided directions for future studies on AOPs.

Potent Half-Sandwich 16-/18-Electron Iridium(III) and Ruthenium(II) Anticancer Complexes with Readily Available Amine-Imine Ligands

The synthesis and biological evaluation of stable 16-electron half-sandwich complexes have remained scarce. We herein present the different coordination modes (16-electron or 18-electron) between half-sandwich iridium(III) complexes and ruthenium(II) complexes derived from the same amine-imine ligands chelating hybrid sp3-N/sp2-N donors. The 16-electron iridium(III) and 18-electron ruthenium(II) complexes with different counteranions were obtained and identified by various techniques. The promising cytotoxicity of these complexes against A549 lung cancer cells, cisplatin-resistant A549/DPP cells, cervical carcinoma HeLa cells, and human hepatocellular liver carcinoma HepG2 cells was observed with IC50 values ranging from 5.4 to 16.3 μM. Moreover, these complexes showed a certain selectivity (selectivity index: 2.1-3.7) toward A549 cells and BEAS-2B normal cells. The variation of metal center, counteranion, 16/18-electron coordination mode, and ligand substituents showed little influence on the cytotoxicity and selectivity of these complexes. The mechanism of action study showed that these complexes could target mitochondria, induce the depolarization of the mitochondrial membrane, and promote the generation of intracellular reactive oxygen species (ROS). Further, the induction of cell apoptosis and the perturbation of the cell cycle in the G0/G1 phase were also observed for these complexes. Overall, it seems that the redox mechanism dominated the anticancer efficacy of these complexes.

Erythroid Cells as Full Participants in the Tumor Microenvironment

The tumor microenvironment is an important factor that can determine the success or failure of antitumor therapy. Cells of hematopoietic origin are one of the most important mediators of the tumor-host interaction and, depending on the cell type and functional state, exert pro- or antitumor effects in the tumor microenvironment or in adjacent tissues. Erythroid cells can be full members of the tumor microenvironment and exhibit immunoregulatory properties. Tumor growth is accompanied by the need to obtain growth factors and oxygen, which stimulates the appearance of the foci of extramedullary erythropoiesis. Tumor cells create conditions to maintain the long-term proliferation and viability of erythroid cells. In turn, tumor erythroid cells have a number of mechanisms to suppress the antitumor immune response. This review considers current data on the existence of erythroid cells in the tumor microenvironment, formation of angiogenic clusters, and creation of optimal conditions for tumor growth. Despite being the most important life-support function of the body, erythroid cells support tumor growth and do not work against it. The study of various signaling mechanisms linking tumor growth with the mobilization of erythroid cells and the phenotypic and functional differences between erythroid cells of different origin allows us to identify potential targets for immunotherapy.

6-(7-Nitro-2,1,3-benzoxadiazol-4-ylthio) Hexanol Inhibits Proliferation and Induces Apoptosis of Endometriosis by Regulating Glutathione S-Transferase Mu Class 4

Endometriosis is a chronic disease associated with a disrupted oxidative balance and chronic inflammation. In this study, we investigated the role of glutathione S-transferase Mu class 4 (GSTM4) in endometriosis and determined whether 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio) hexanol (NBDHEX) regulates GSTM4 expression to affect cellular functions and oxidative stress. GSTM4 expression was detected by immunohistochemistry in endometrium from 15 endometriosis patients and 15 healthy controls. Western blotting was used to detect the expression of GSTM4, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase-9 (MMP-9), Survivin, B-cell lymphoma-extra-large (Bcl-XL), Bax, kelch-like ECH-associated protein 1 (Keap1), and nuclear factor-erythroid 2-related factor 2 (Nrf2) in primary endometrial stromal cells with endometriosis (EESC) and normal endometrial stromal cells (NESC). The effects of NBDHEX on cell proliferation, migration, and invasion were evaluated using Cell Counting Kit-8 (CCK8) and Transwell assays. Apoptosis was detected by flow cytometry. The expression of GSTM4 was significantly increased in endometrium from endometriosis patients. Upon NBDHEX treatment, ESC exhibited reduced proliferation, migration and invasion abilities, and increased apoptosis. NBDHEX decreased the expression of endometriosis prognostic markers (PCNA and MMP-9) and anti-apoptotic proteins (Survivin and Bcl-xl), while it increased the expression of the apoptotic protein Bax. It had no effect on Keap1 expression, and it decreased the expression of Nrf2. The effect of siRNA-mediated knockdown of GSTM4 was similar to that of suppressing GSTM4 expression with NBDHEX treatment. These results indicate that GSTM4 is highly expressed in endometriosis and its expression is inhibited by NBDHEX. Decreased expression of GSTM4 inhibits cell growth, migration, and invasion, and negatively regulates Nrf2 to affect oxidative stress-induced apoptosis. Our results suggest that GSTM4 may play a role in ameliorating the progression of endometriosis. NBDHEX may have therapeutic potential in the treatment of endometriosis.

The role of redox-mediated lysosomal dysfunction and therapeutic strategies

Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological activities of the body. The imbalance of redox homeostasis can lead to the development of various human diseases. Lysosomes regulate the degradation of cellular proteins and play an important role in influencing cell function and fate, and lysosomal dysfunction is closely associated with the development of various diseases. In addition, several studies have shown that redox homeostasis plays a direct or indirect role in regulating lysosomes. Therefore, this paper systematically reviews the role and mechanisms of redox homeostasis in the regulation of lysosomal function. Therapeutic strategies based on the regulation of redox exerted to disrupt or restore lysosomal function are further discussed. Uncovering the role of redox in the regulation of lysosomes helps to point new directions for the treatment of many human diseases.

Extracellular vesicle-matrix interactions

The extracellular matrix in microenvironments harbors a variety of signals to control cellular functions and the materiality of tissues. Most efforts to synthetically reconstitute the matrix by biomaterial design have focused on decoupling cell-secreted and polymer-based cues. Cells package molecules into nanoscale lipid membrane-bound extracellular vesicles and secrete them. Thus, extracellular vesicles inherently interact with the meshwork of the extracellular matrix. In this Review, we discuss various aspects of extracellular vesicle-matrix interactions. Cells receive feedback from the extracellular matrix and leverage intracellular processes to control the biogenesis of extracellular vesicles. Once secreted, various biomolecular and biophysical factors determine whether extracellular vesicles are locally incorporated into the matrix or transported out of the matrix to be taken up by other cells or deposited into tissues at a distal location. These insights can be utilized to develop engineered biomaterials where EV release and retention can be precisely controlled in host tissue to elicit various biological and therapeutic outcomes.

Effects of Flavonoids on Cancer, Cardiovascular and Neurodegenerative Diseases: Role of NF-κB Signaling Pathway

Flavonoids are polyphenolic phytochemical compounds found in many plants, fruits, vegetables, and leaves. They have a multitude of medicinal applications due to their anti-inflammatory, antioxidative, antiviral, and anticarcinogenic properties. Furthermore, they also have neuroprotective and cardioprotective effects. Their biological properties depend on the chemical structure of flavonoids, their mechanism of action, and their bioavailability. The beneficial effects of flavonoids have been proven for a variety of diseases. In the last few years, it is demonstrated that the effects of flavonoids are mediated by inhibiting the NF-κB (Nuclear Factor-κB) pathway. In this review, we have summarized the effects of some flavonoids on the most common diseases, such as cancer, cardiovascular, and human neurodegenerative diseases. Here, we collected all recent studies describing the protective and prevention role of flavonoids derived from plants by specifically focusing their action on the NF-κB signaling pathway.

Quercetin-Induced Glutathione Depletion Sensitizes Colorectal Cancer Cells to Oxaliplatin

Quercetin is an antioxidant phytochemical which belongs to the natural flavonoids group. Recently, the compound has been reported to inhibit glutathione reductase responsible for replenishing reduced forms of glutathione and thus leads to glutathione depletion, triggering cell death. In this study, we examined if quercetin sensitizes tumors to oxaliplatin by inhibiting glutathione reductase activity in human colorectal cancer cells, and thereby facilitates apoptotic cell death. A combined treatment with quercetin and oxaliplatin was found to synergistically inhibit glutathione reductase activity, lower intracellular glutathione level, increase reactive oxygen species production, and reduce cell viability, compared to treatment with oxaliplatin alone in human colorectal HCT116 cancer cells. Furthermore, the incorporation of sulforaphane, recognized for its ability to scavenge glutathione, in combination with quercetin and oxaliplatin, substantially suppressed tumor growth in an HCT116 xenograft mouse model. These findings suggest that the depletion of intracellular glutathione by quercetin and sulforaphane could strengthen the anti-cancer efficacy of oxaliplatin.

In Vitro Biological Activity and Lymphoma Cell Growth Inhibition by Selected Mexican Medicinal Plants

Cancer is a major health problem with significant morbidity and mortality. In addition, plants are a source of metabolites with diverse biological properties, including antitumor potential. In this study, we investigated the in vitro murine lymphoma L5178Y-R cell growth inhibition, human peripheral blood mononuclear cells (PBMC) toxicity and proliferation, and antioxidant, hemolytic, and anti-hemolytic activities of methanol extracts from 15 plants of traditional use in Mexico. Justicia spicigera caused the highest tumor cell growth inhibition with a half maximal inhibitory concentration (IC50) of 29.10 µg/mL and a selectivity index >34.36 compared with those of PBMC, whereas Mimosa tenuiflora showed the highest lymphoproliferative activity from 200 µg/mL compared with that induced by concanavalin A. In addition, M. tenuiflora showed an antioxidant effect (IC50 = 2.86 µg/mL) higher than that of ascorbic acid. Regarding the hemolytic and anti-hemolytic activity, all extracts presented significant anti-hemolytic activity. The extract of J. spicigera is emerging as a possible source of effective antineoplastic compounds.

Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology

Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, preserving ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.

Syringol, a wildfire residual methoxyphenol causes cytotoxicity and teratogenicity in zebrafish model

Natural toxicants, particularly methoxy phenols (MPs) generated by wildfire lignin, can accumulate in the environment, and cause serious health hazards in living organisms. Although the toxicity of MPs such as guaiacol and catechol has recently been described, there is minimal evidence of ecotoxicological effects of syringol. As a result, this study focuses on determining the toxicity by evaluating the cytotoxic and teratogenic effects of syringol in vitro and in vivo in human embryonic kidney (HEK-293) cells and zebrafish embryos, respectively. The ecotoxicity of syringol was predicted to be 63.8 mg/L using the ECOSAR (ECOlogical Structure Activity Relationship) prediction tool, and molecular docking analysis was used to determine the interaction and binding affinities of syringol with human apoptotic proteins in silico. In HEK-293 cells, exposure of syringol (0.5-2 mg/L) has induced cytotoxicity in a concentration-dependent manner. In zebrafish larvae, exposure of syringol (0.5-2 mg/L) has induced dose-dependent embryo toxic effects (or growth abnormalities such as yolk sac edema, pericardial edema, skeletal abnormality, and hyperemia), and changes in growth morphometrics (head height, eye, yolk sac, and pericardial area, heart rate) in particular, the heart rate of larvae was found to be significantly decreased (p<0.001). After a 4-day experimental trial, the accumulated concentration of syringol in zebrafish larvae was confirmed both qualitatively (HPLC-MS - High Performance Liquid Chromatography-Mass spectrometry) and quantitatively (LC-QTOF-HRMS - Liquid Chromatography-Quadrupolar Time of Flight-High Resolution Mass spectrometry). The craniofacial abnormalities induced by syringol exposure (0.5-2 mg/L) were detected as anomalies in cartilaginous development and locomotor deficits using alcian blue staining and locomotor analyses, respectively. Significant increase in oxidative stress parameters (including reactive oxygen species generation, lipid peroxidation, superoxide dismutase, catalase, lactate dehydrogenase and nitric oxide production) (p<0.001) and substantial decrease in glutathione levels were observed (p<0.05) in syringol exposed zebrafish larvae through enzymatic analysis. Additionally, through acridine orange staining and gene expression analyses, syringol (2 mg/L) was found to activate apoptosis in zebrafish larvae. Considering the cytotoxic, embryotoxic (teratogenicity), and oxidative stress-related apoptotic effects of syringol in the zebrafish model, syringol has the potential to emerge as a potent environmental toxicant posing serious health hazards in many living systems; however, further research on its toxicological effects on the actual ecosystem and in higher animal models is required to confirm its consequences.

Anti-cancer effect of Rumex obtusifolius in combination with arginase/nitric oxide synthase inhibitors via downregulation of oxidative stress, inflammation, and polyamine synthesis

Cancer continues to be a leading cause of death worldwide, making the development of new treatment methods crucial in the fight against it. With cancer incidence rates increasing worldwide, ongoing research must focus on identifying new and effective ways to prevent and treat the disease. The combination of herbal extracts with chemotherapeutic agents has gained much interest as a novel strategy to combat cancer. Rumex obtusifolius L. is a wild plant known for its medicinal properties and is widely distributed worldwide. Our preclinical evaluations suggested that R. obtusifolius seed extracts possessed cancer-inhibiting properties and we also evaluated the beneficial effects of the arginase inhibitor NG-hydroxy-nor-L-arginine and nitric oxide inhibitor NG-nitro-L-arginine methyl ester in the treatment of breast cancer. The current study aimed to combine these observations and evaluate the antioxidant and antitumor properties of R. obtusifolius extracts alone and in combination with the arginase and nitric oxide synthase inhibitors. Metabolic characterization of the plant extract using a liquid chromatography/high-resolution mass spectrometry advanced system revealed the presence of 240 phenolic compounds many of which possess anticancer properties, according to the literature. In vitro studies revealed a significant cytotoxic effect of the R. obtusifolius extracts on the human colon (HT29) and breast cancer (MCF-7) cell lines. Thus, a new treatment approach of combining R. obtusifolius bioactive phytochemicals with the arginase and nitric oxide synthase inhibitors NG-nitro-L-arginine methyl ester and/or NG-hydroxy-nor-L-arginine, respectively, was proposed and could potentially be an effective way to treat breast cancer. Indeed, these combinations showed immunostimulatory, antiproliferative, antioxidant, anti-inflammatory, and antiangiogenic properties in a rat breast cancer model.

Immunomodulatory function and anti-tumor mechanism of natural polysaccharides: A review

Polysaccharides extracted from natural resources have attracted extensive attention in biomedical research and pharmaceutical fields, due to their medical values in anti-tumor, immunomodulation, drug delivery, and many other aspects. At present, a variety of natural polysaccharides have been developed as adjuvant drugs in clinical application. Benefit from their structural variability, polysaccharides have great potential in regulating cellular signals. Some polysaccharides exert direct anti-tumor effects by inducing cell cycle arrest and apoptosis, while the majority of polysaccharides can regulate the host immune system and indirectly inhibit tumors by activating either non-specific or specific immune responses. As the essential of microenvironment in the process of tumor development has been gradually revealed, some polysaccharides were found to inhibit the proliferation and metastasis of tumor cells via tumoral niche modulation. Here, we focused on natural polysaccharides with biomedical application potential, reviewed the recent advancement in their immunomodulation function and highlighted the importance of their signaling transduction feature for the antitumor drug development.

Oral Submucous Fibrosis: Etiological Mechanism, Malignant Transformation, Therapeutic Approaches and Targets

Oral submucosal fibrosis (OSF) is a chronic, progressive and potentially malignant oral disorder with a high regional incidence and malignant rate. With the development of the disease, the normal oral function and social life of patients are seriously affected. This review mainly introduces the various pathogenic factors and mechanisms of OSF, the mechanism of malignant transformation into oral squamous cell carcinoma (OSCC), and the existing treatment methods and new therapeutic targets and drugs. This paper summarizes the key molecules in the pathogenic and malignant mechanism of OSF, the miRNAs and lncRNAs with abnormal changes, and the natural compounds with therapeutic effects, which provides new molecular targets and further research directions for the prevention and treatment of OSF.

Metabolic dialogs between B cells and the tumor microenvironment: Implications for anticancer immunity

Immunometabolism, a branch of biology describing the link between immunity and metabolism, is an emerging topic in cancer immunology. It is currently well accepted that B cells and tertiary lymph structures formed by them are associated with favorable outcomes when patients undergo cancer immunotherapy. Understanding the determinants of B-cell fate and function in cancer patients is necessary for improving cancer immunotherapy. Accumulating evidence points to the tumor microenvironment being a critical metabolic hurdle to an efficient antitumor B-cell response. At the same time, several B-cell-derived metabolites have recently been reported to inhibit anticancer immunity. In this literature review, key B-cell immunometabolism studies and the metabolic life of B cells were summarized. Then, we discussed the intrinsic metabolic pathways of B cells themselves and how the tumor microenvironment and B cells in tumors metabolically influence each other. Finally, we pointed out key questions to provide some inspiration for further study of the role of B-cell immunometabolism in the antitumor immune response.

Activation of NOTCH signaling via DLL1 is mediated by APE1-redox-dependent NF-κB activation in oesophageal adenocarcinoma

OBJECTIVE

Oesophageal adenocarcinoma (EAC) arises in the setting of Barrett's oesophagus, an intestinal metaplastic precursor lesion that can develop in patients with chronic GERD. Here, we investigated the role of acidic bile salts, the mimicry of reflux, in activation of NOTCH signaling in EAC.

DESIGN

This study used public databases, EAC cell line models, L2-IL1β transgenic mouse model and human EAC tissue samples to identify mechanisms of NOTCH activation under reflux conditions.

RESULTS

Analysis of public databases demonstrated significant upregulation of NOTCH signaling components in EAC. In vitro studies demonstrated nuclear accumulation of active NOTCH1 cleaved fragment (NOTCH intracellular domain) and upregulation of NOTCH targets in EAC cells in response to reflux conditions. Additional investigations identified DLL1 as the predominant ligand contributing to NOTCH1 activation under reflux conditions. We discovered a novel crosstalk between APE1 redox function, reflux-induced inflammation and DLL1 upregulation where NF-κB can directly bind to and induce the expression of DLL1. The APE1 redox function was crucial for activation of the APE1-NF-κB-NOTCH axis and promoting cancer cell stem-like properties in response to reflux conditions. Overexpression of APE1 and DLL1 was detected in gastro-oesophageal junctions of the L2-IL1ß transgenic mouse model and human EAC tissue microarrays. DLL1 high levels were associated with poor overall survival in patients with EAC.

CONCLUSION

These findings underscore a unique mechanism that links redox balance, inflammation and embryonic development (NOTCH) into a common pro-tumorigenic pathway that is intrinsic to EAC cells.

GPX3 expression was down-regulated but positively correlated with poor outcome in human cancers

Introduction

Cancer is a crucial public health problem and one of the leading causes of death worldwide. Previous studies have suggested that GPX3 may be involved in cancer metastasis and chemotherapy resistance. However, how GPX3 affects cancer patients' outcomes and the underlying mechanism remains unclear.

Methods

Sequencing data and clinical data from TCGA, GTEx, HPA, and CPTAC were used to explore the relationship between GPX3 expression and clinical features. Immunoinfiltration scores were used to assess the relationship between GPX3 and the tumor immune microenvironment. Functional enrichment analysis was used to predict the role of GPX3 in tumors. Gene mutation frequency, methylation level, and histone modification were used to predict the GPX3 expression regulation method. Breast, ovarian, colon, and gastric cancer cells were used to investigate the relationship between GPX3 expression and cancer cell metastasis, proliferation, and chemotherapy sensitivity.

Results

GPX3 is down-regulated in various tumor tissues, and GPX3 expression level can be used as a marker for cancer diagnosis. However, GPX3 expression is associated with higher stage and lymph node metastasis, as well as poorer prognosis. GPX3 is closely related to thyroid function and antioxidant function, and its expression may be regulated by epigenetic inheritance such as methylation modification or histone modification. In vitro experiments, GPX3 expression is associated with cancer cell sensitivity to oxidant and platinum-based chemotherapy and is involved in tumor metastasis in oxidative environments.

Discussion

We explored the relationship between GPX3 and clinical features, immune infiltration characteristics, migration and metastasis, and chemotherapy sensitivities of human cancers. We further investigated the potential genetic and epigenetic regulation of GPX3 in cancer. Our results suggested that GPX3 plays a complicated role in the tumor microenvironment, simultaneously promoting metastasis and chemotherapy resistance in human cancers.

The regulation loop of MARVELD1 interacting with PARP1 in DNA damage response maintains genome stability and promotes therapy resistance of cancer cells

The DNA damage response (DDR) plays crucial roles in cancer prevention and therapy. Poly(ADP-ribose) polymerase 1 (PARP1) mediates multiple signal transduction in the DDR as a master regulator. Uncovering the regulatory factors of PARP1 contributes to a more comprehensive view of tumorigenesis and treatment strategies. Here, we reveal that MARVELD1 acts as a mediator of DDR to perform early events and maintain genome stability. Mechanistically, PARP1 PARylates MARVELD1 at D102, D118 and D130, and in turn, MARVELD1 stabilizes PARP1 by enhancing NAA50-mediated acetylation, thus forming a positive feedback loop. MARVELD1 knockout mice and their embryo fibroblasts exhibit genomic instability and shorter half-life of PARP1. Moreover, MARVELD1 partnering with PARP1 facilitates resistance to genotoxic drugs and disrupts PARP inhibitor (PARPi) effect in PDX model of colorectal cancer (CRC). Overall, our results underline the link between MARVELD1 and PARP1 in therapeutic resistance based on DDR and provide new insights for clinical tumor therapy of PARPi.

The Regulatory Effect of Phytochemicals on Chronic Diseases by Targeting Nrf2-ARE Signaling Pathway

Redox balance is essential to maintain the body's normal metabolism. Once disrupted, it may lead to various chronic diseases, such as diabetes, neurodegenerative diseases, cardiovascular diseases, inflammatory diseases, cancer, aging, etc. Oxidative stress can cause or aggravate a series of pathological processes. Inhibition of oxidative stress and related pathological processes can help to ameliorate these chronic diseases, which have been found to be associated with Nrf2 activation. Nrf2 activation can not only regulate the expression of a series of antioxidant genes that reduce oxidative stress and its damage, but also directly regulate genes related to the above-mentioned pathological processes to counter the corresponding changes. Therefore, targeting Nrf2 has great potential for the prevention or treatment of chronic diseases, and many natural phytochemicals have been reported as Nrf2 activators although the defined mechanisms remain to be elucidated. This review article focuses on the possible mechanism of Nrf2 activation by natural phytochemicals in the prevention or treatment of chronic diseases and the regulation of oxidative stress. Moreover, the current clinical trials of phytochemical-originated drug discovery by targeting the Nrf2-ARE pathway were also summarized; the outcomes or the relationship between phytochemicals and chronic diseases prevention are finally analyzed to propose the future research strategies and prospective.

Epigenetics and Metabolism Reprogramming Interplay into Glioblastoma: Novel Insights on Immunosuppressive Mechanisms

The central nervous system represents a complex environment in which glioblastoma adapts skillfully, unleashing a series of mechanisms suitable for its efficient development and diffusion. In particular, changes in gene expression and mutational events that fall within the domain of epigenetics interact complexly with metabolic reprogramming and stress responses enacted in the tumor microenvironment, which in turn fuel genomic instability by providing substrates for DNA modifications. The aim of this review is to analyze this complex interaction that consolidates several conditions that confer a state of immunosuppression and immunoevasion, making glioblastoma capable of escaping attack and elimination by immune cells and therefore invincible against current therapies. The progressive knowledge of the cellular mechanisms that underlie the resistance of the glioblastoma represents, in fact, the only weapon to unmask its weak points to be exploited to plan successful therapeutic strategies.

Free Radicals and Oxidative Stress: Signaling Mechanisms, Redox Basis for Human Diseases, and Cell Cycle Regulation

Free radicals contain one or more unpaired electrons in their valence shell, thus making them unstable, short-lived, and highly reactive species. Excessive generation of these free radicals ultimately leads to oxidative stress causing oxidation and damage to significant macromolecules in the living system and essentially disrupting signal transduction pathways and antioxidants equilibrium. At lower concentrations, ROS serves as "second messengers," influencing many physiological processes in the cell. However, higher concentrations beyond cell capacity cause oxidative stress, contributing to human pathologies such as diabetes, cancer, Parkinson's disease, cardiovascular diseases, cataract, asthma, hypertension, atherosclerosis, arthritis, and Alzheimer's disease. Signaling pathways such as NF-κB, MAPKs, PI3K/Akt/ mTOR, and Keap1-Nrf2- ARE modulate the detrimental effects of oxidative stress by increasing the expression of cellular antioxidant defenses, phase II detoxification enzymes, and decreased production of ROS. Free radicals such as H2O2 are indeed needed for the advancement of the cell cycle as these molecules influence DNA, proteins, and enzymes in the cell cycle pathway. In the course of cell cycle progression, the cellular redox environment becomes more oxidized, moving from the G1 phase, becoming higher in G2/M and moderate in the S phase. Signals in the form of an increase in cellular pro-oxidant levels are required, and these signals are often terminated by a rise in the amount of antioxidants and MnSOD with a decrease in the level of cyclin D1 proteins. Therefore, understanding the mechanism of cell cycle redox regulation will help in the therapy of many diseases.

Concomitant selenoenzyme inhibitor exposures as etiologic contributors to disease: Implications for preventative medicine

The physiological activities of selenium (Se) occur through enzymes that incorporate selenocysteine (Sec), a rare but important amino acid. The human genome includes 25 genes coding for Sec that employ it to catalyze challenging reactions. Selenoenzymes control thyroid hormones, calcium activities, immune responses, and perform other vital roles, but most are devoted to preventing and reversing oxidative damage. As the most potent intracellular nucleophile (pKa 5.2), Sec is vulnerable to binding by metallic and organic soft electrophiles (E*). These electron poor reactants initially form covalent bonds with nucleophiles such as cysteine (Cys) whose thiol (pKa 8.3) forms adducts which function as suicide substrates for selenoenzymes. These adducts orient E* to interact with Sec and since Se has a higher affinity for E* than sulfur, the E* transfers to Sec and irreversibly inhibits the enzyme's activity. Organic electrophiles have lower Se-binding affinities than metallic E*, but exposure sources are more abundant. Individuals with poor Se status are more vulnerable to the toxic effects of high E* exposures. The relative E*:Se stoichiometries remain undefined, but the aggregate effects of multiple E* exposures are predicted to be additive and possibly synergistic under certain conditions. The potential for the combined Se-binding effects of common pharmaceutical, dietary, or environmental E* require study, but even temporary loss of selenoenzyme activities would accentuate oxidative damage to tissues. As various degenerative diseases are associated with accumulating DNA damage, defining the effects of complementary E* exposures on selenoenzyme activities may enhance the ability of preventative medicine to support healthy aging.

Hypoglycemic Effect of the N-Butanol Fraction of Torreya grandis Leaves on Type 2 Diabetes Mellitus in Rats through the Amelioration of Oxidative Stress and Enhancement of β-Cell Function

Materials and Methods

Sprague-Dawley rats were randomly divided into six groups: control, T2DM, metformin, high-dose BFTL (800 mg/kg), middle-dose BFTL (400 mg/kg), and low-dose BFTL (200 mg/kg). After 4 weeks of BFTL treatment, the correlations of serum indicators with protein expression in tissue were determined, and pathological changes in the liver, kidneys, and pancreas were analyzed.

Results

Compared with the results in the T2DM group, serum fasting blood glucose, triglyceride, total cholesterol, malondialdehyde, alanine aminotransferase, and aspartate aminotransferase levels were significantly decreased (p < 0.05), whereas superoxide dismutase and glutathione peroxidase levels were significantly increased (p < 0.05) in the high-, middle-, and low-dose BFTL groups. The treatment also improved oral glucose tolerance. In addition, the pathological changes of the liver, kidney, and pancreas were improved by BFTL treatment. Cytochrome and caspase-3 expression in pancreatic was significantly decreased (p < 0.05) by BFTL treatment, whereas the Bcl-2/Bax ratio was significantly increased (p < 0.05). Discussion and Conclusion. BFTL exerted significant hypoglycemic effect on T2DM model rats, and its mechanism involved the suppression of blood glucose levels and oxidative stress by improving the metabolism of blood lipids and antioxidant capacity, boosting β-cell function, and inhibiting β-cell apoptosis.

Regulatory Components of Oxidative Stress and Inflammation and Their Complex Interplay in Carcinogenesis

Cancer progression is closely linked to oxidative stress (OS) inflammation. OS is caused by an imbalance between the amount of reactive oxygen species produced and antioxidants present in the body. Excess ROS either oxidizes biomolecules or activates the signaling cascade, resulting in inflammation. Immune cells secrete cytokines and chemokines when inflammation is activated. These signaling molecules attract a wide range of immune cells to the site of infection or oxidative stress. Similarly, increased ROS production by immune cells at the inflamed site causes oxidative stress in the affected area. A review on the role of oxidative stress and inflammation in cancer-related literature was conducted to obtain data. All of the information gathered was focused on the current state of oxidative stress and inflammation in various cancers. After gathering all relevant information, a narrative review was created to provide a detailed note on oxidative stress and inflammation in cancer. Proliferation, differentiation, angiogenesis, migration, invasion, metabolic changes, and evasion of programmed cell death are all aided by OS and inflammation in cancer. Imbalance between reactive oxygen species (ROS) and antioxidants lead to oxidative stress that damages macromolecules (nucleic acids, lipids and proteins). It causes breakdown of the biological signaling cascade. Prolonged oxidative stress causes inflammation by activating transcription factors (NF-κB, p53, HIF-1α, PPAR-γ, Nrf2, AP-1) that alter the expression of many other genes and proteins, including growth factors, tumor-suppressor genes, oncogenes, and pro-inflammatory cytokines, resulting in cancer cell survival. The present review article examines the complex relationship between OS and inflammation in certain types of cancer (colorectal, breast, lung, bladder, and gastric cancer).

Redox balance and autophagy regulation in cancer progression and their therapeutic perspective

Cellular ROS production participates in various cellular functions but its accumulation decides the cell fate. Malignant cells have higher levels of ROS and active antioxidant machinery, a characteristic hallmark of cancer with an outcome of activation of stress-induced pathways like autophagy. Autophagy is an intracellular catabolic process that produces alternative raw materials to meet the energy demand of cells and is influenced by the cellular redox state thus playing a definite role in cancer cell fate. Since damaged mitochondria are the main source of ROS in the cell, however, cancer cells remove them by upregulating the process of mitophagy which is known to play a decisive role in tumorigenesis and tumor progression. Chemotherapy exploits cell machinery which results in the accumulation of toxic levels of ROS in cells resulting in cell death by activating either of the pathways like apoptosis, necrosis, ferroptosis or autophagy in them. So understanding these redox and autophagy regulations offers a promising method to design and develop new cancer therapies that can be very effective and durable for years. This review will give a summary of the current therapeutic molecules targeting redox regulation and autophagy for the treatment of cancer. Further, it will highlight various challenges in developing anticancer agents due to autophagy and ROS regulation in the cell and insights into the development of future therapies.

Prognostic role of pre-treatment serum ALB in Patients with oropharyngeal cancer: A retrospective cohort study

BACKGROUND

The morbidity of oropharyngeal cancer (OPC) is continuing to rise in numerous developed countries. An accurate prognostic assessment is needed to evaluate the malignant degree or risk classification to optimize treatment. Albumin (ALB) as an independent prognostic indicator of cancer survival has been established in previous studies. This study investigated the prognostic value of pre-treatment serum ALB in OPC patients.

METHODS

The clinicopathological data of 246 patients diagnosed with OPC from 2010 to 2019 were analyzed retrospectively. Analyze the relationship between ALB and clinicopathological characteristics of patients. The optimal cut-off values for ALB were determined via Cutoff Finder (Method for cutoff determination: Survival: significance (log-rank test)). To determine the independent prognostic factors, the Cox proportional hazards model was used to perform univariate and multivariate analyses of the serum ALB levels related to overall survival (OS) and disease-free survival (DFS).

RESULTS

The optimal cut-off point for ALB was 39.15 g/L determined via Cutoff Finder. Serum ALB levels were significantly associated with age (P=0.047), Presence of comorbidity (P=0.009), Charlson score index (P=0.007), Hemoglobin (P<0.001), Neutrophil to Lymphocyte Ratio (P=0.002), Albumin-To-Alkaline Phosphatase Ratio (P<0.001), Alkaline phosphatase (P=0.005), T stage (P=0.016), and HPV status (P=0.002). In the univariate and multivariate analyses, ALB was found to be an independent prognostic indicator for DFS (HR =0.39, 95% CI:0.23-0.66, P=0.000) and OS (HR =0.46, 95% CI: 0.25-0.83, P=0.01) in OPC patients.

CONCLUSIONS

Pre-treatment serum ALB could serve as a valuable prognostic biomarker for the prognostic stratification of OPC patients.

Methanol Extract of Commelina Plant Inhibits Oral Cancer Cell Proliferation

Data regarding the effects of crude extract of Commelina plants in oral cancer treatment are scarce. This present study aimed to assess the proliferation-modulating effects of the Commelina sp. (MECO) methanol extract on oral cancer cells in culture, Ca9-22, and CAL 27. MECO suppressed viability to a greater extent in oral cancer cells than in normal cells. MECO also induced more annexin V, apoptosis, and caspase signaling for caspases 3/8/9 in oral cancer cells. The preferential antiproliferation and apoptosis were associated with cellular and mitochondrial oxidative stress in oral cancer cells. Moreover, MECO also preferentially induced DNA damage in oral cancer cells by elevating γH2AX and 8-hydroxyl-2′-deoxyguanosine. The oxidative stress scavengers N-acetylcysteine or MitoTEMPO reverted these preferential antiproliferation mechanisms. It can be concluded that MECO is a natural product with preferential antiproliferation effects and exhibits an oxidative stress-associated mechanism in oral cancer cells.

NRF2 Mediates Cellular Resistance to Transformation, Radiation, and Inflammation in Mice

Nuclear factor erythroid 2-related factor 2 (NRF2) is recognized as a master transcription factor that regulates expression of numerous detoxifying and antioxidant cytoprotective genes. In fact, models of NRF2 deficiency indicate roles not only in redox regulation, but also in metabolism, inflammatory/autoimmune disease, cancer, and radioresistancy. Since ionizing radiation (IR) generates reactive oxygen species (ROS), it is not surprising it activates NRF2 pathways. However, unexpectedly, activation is often delayed for many days after the initial ROS burst. Here, we demonstrate that, as assayed by γ-H2AX staining, rapid DNA double strand break (DSB) formation by IR in primary mouse Nrf2-/- MEFs was not affected by loss of NRF2, and neither was DSB repair to any great extent. In spite of this, basal and IR-induced transformation was greatly enhanced, suggesting that NRF2 protects against late IR-induced genomic instability, at least in murine MEFs. Another possible IR- and NRF2-related event that could be altered is inflammation and NRF2 deficiency increased IR-induced NF-κB pro-inflammatory responses mostly late after exposure. The proclivity of NRF2 to restrain inflammation is also reflected in the reprogramming of tumor antigen-specific lymphocyte responses in mice where Nrf2 k.o. switches Th2 responses to Th1 polarity. Delayed NRF2 responses to IR may be critical for the immune transition from prooxidant inflammation to antioxidant healing as well as in driving cellular radioresistance and survival. Targeting NRF2 to reprogram immunity could be of considerable therapeutic benefit in radiation and immunotherapy.

Advancements in redox-sensitive micelles as nanotheranostics: A new horizon in cancer management

World Health Organisation (WHO) delineated cancer as one of the foremost reasons for mortality with 10 million deaths in the year 2020. Early diagnosis and effective drug delivery are of utmost importance in cancer management. The entrapment of both bio-imaging dyes and drugs will open novel avenues in the area of tumor theranostics. Elevated levels of reactive oxygen species (ROS) and glutathione (GSH) are the characteristic features of the tumor microenvironment (TME). Researchers have taken advantage of these specific TME features in recent years to develop micelle-based theranostic nanosystems. This review focuses on the advantages of redox-sensitive micelles (RSMs) and supramolecular self-assemblies for tumor theranostics. Key chemical linkers employed for the tumor-specific release of the cargo have been discussed. In vitro characterisation techniques used for the characterization of RSMs have been deliberated. Potential bottlenecks that may present themselves in the bench-to-bedside translation of this technology and the regulatory considerations have been deliberated.

Exopolysaccharides from Marine Microbes: Source, Structure and Application

The unique living environment of marine microorganisms endows them with the potential to produce novel chemical compounds with various biological activities. Among them, the exopolysaccharides produced by marine microbes are an important factor for them to survive in these extreme environments. Up to now, exopolysaccharides from marine microbes, especially from extremophiles, have attracted more and more attention due to their structural complexity, biodegradability, biological activities, and biocompatibility. With the development of culture and separation methods, an increasing number of novel exopolysaccharides are being found and investigated. Here, the source, structure and biological activities of exopolysaccharides, as well as their potential applications in environmental restoration fields of the last decade are summarized, indicating the commercial potential of these versatile EPS in different areas, such as food, cosmetic, and biomedical industries, and also in environmental remediation.

Clinical implications of lipid peroxides levels in plasma and tumor tissue in breast cancer patients

Oxidative stress can promote the oxidation of lipoproteins and polyunsaturated fatty acids present in cell membranes; an event known as lipid peroxidation (LPO). LPO has been associated with carcinogenesis and cancer progression, however, its meaning concerning the clinicopathological aspects of human breast cancer is not clear. This study investigated LPO profiles in tumor and plasma samples from breast cancer patients (n = 140) considering their clinicopathological features (age at diagnosis, menopausal status, body mass index, tumor histological grade, tumor size, ki-67 proliferation index, presence of metastasis, chemotherapy response, the molecular subtype of cancer and overall survival status). LPO levels were estimated by tert-butyl hydroperoxide-initiated chemiluminescence. High LPO levels were found regarding poor prognosis parameters as young age at diagnosis (p = 0.006 in tissue), premenopausal patients (p = 0.012 in tissue), high-grade tumors (p = 0.010 in tissue and p = 0.002 in plasma), metastatic disease (p = 0.046 in tissue), chemoresistant tumors (p = 0.041 in tissue), disease relapse (p = 0.018 in tissue and p = 0.009 in plasma) and overall survival status (p = 0.001 in plasma). Our findings point out the clinical meaning of LPO and highlight it as an oxidative stress event linked to poor prognosis and disease aggressiveness in breast cancer patients.

Regulating Effect of Cytochrome b5 Overexpression on Human Breast Cancer Cells

Imbalance in the cellular redox system is thought to be associated with the induction and progression of breast cancers, and heme proteins may regulate the redox balance. Cytochrome b₅ (Cyt b₅) is a small mitochondrial heme protein. Its function and regulating mechanism in breast cancer remain unknown. In this study, we elucidated the level of endogenous oxidative stress in breast cancer cells, MCF-7 cells (hormone receptor-positive cells) and MDA-MB-231 cells (triple-negative cells), and investigated the difference in Cyt b₅ content. Based on the low content of Cyt b₅ in MDA-MB-231 cells, the overexpression of Cyt b₅ was found to regulate the oxidative stress and apoptosis cascades, including ERK1/2 and Akt signaling pathways. The overexpressed Cyt b₅ MDA-MB-231 cells were shown to exhibit decreased oxidative stress, less phosphorylation of ERK1/2 and Akt, and less cleavage of caspases 3 and 9 upon treatment with H₂O₂, as compared to those of normal MDA-MB-231 cells. Moreover, the overexpressed Cyt b₅ most likely functioned by interacting with its protein partner, Cyt c, as suggested by co-immunoprecipitation studies. These results indicated that Cyt b₅ has different effects on breast cancer cells of different phenotypes, which provides useful information for understanding the multiple roles of Cyt b₅ and provides clues for clinical treatment.

The Bioactivities of Phycocyanobilin from Spirulina

Phycocyanobilin (PCB) is a linear open-chain tetrapyrrole chromophore that captures and senses light and a variety of biological activities, such as anti-oxidation, anti-cancer, and anti-inflammatory. In this paper, the biological activities of PCB are reviewed, and the related mechanism of PCB and its latest application in disease treatment are introduced. PCB can resist oxidation by scavenging free radicals, inhibiting the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and delaying the activity of antioxidant enzymes. In addition, PCB can also be used as an excellent anti-inflammatory agent to reduce the proinflammatory factors IL-6 and IFN-γ and to up-regulate the production of anti-inflammatory cytokine IL-10 by inhibiting the inflammatory signal pathways NF-κB and mitogen-activated protein kinase (MAPK). Due to the above biological activities of phycocyanobilin PCB, it is expected to become a new effective drug for treating various diseases, such as COVID-19 complications, atherosclerosis, multiple sclerosis (MS), and ischaemic stroke (IS).

The Role of the Thioredoxin Detoxification System in Cancer Progression and Resistance

The intracellular redox homeostasis is a dynamic balancing system between the levels of free radical species and antioxidant enzymes and small molecules at the core of cellular defense mechanisms. The thioredoxin (Trx) system is an important detoxification system regulating the redox milieu. This system is one of the key regulators of cells’ proliferative potential as well, through the reduction of key proteins. Increased oxidative stress characterizes highly proliferative, metabolically hyperactive cancer cells, which are forced to mobilize antioxidant enzymes to balance the increase in free radical concentration and prevent irreversible damage and cell death. Components of the Trx system are involved in high-rate proliferation and activation of pro-survival mechanisms in cancer cells, particularly those facing increased oxidative stress. This review addresses the importance of the targetable redox-regulating Trx system in tumor progression, as well as in detoxification and protection of cancer cells from oxidative stress and drug-induced cytotoxicity. It also discusses the cancer cells’ counteracting mechanisms to the Trx system inhibition and presents several inhibitors of the Trx system as prospective candidates for cytostatics’ adjuvants. This manuscript further emphasizes the importance of developing novel multitarget therapies encompassing the Trx system inhibition to overcome cancer treatment limitations.

Investigation of Cytotoxicity and Oxidative Stress Induced by the Pyrethroid Bioallethrin in Human Glioblastoma Cells: The Protective Effect of Vitamin E (VE) and Its Underlying Mechanism

Bioallethrin belongs to the family of pyrethroid insecticides. Previous studies have shown that bioallethrin affected the function of muscarinic receptor and subsequently induced neurotoxicity in different brain models. Reactive oxygen species (ROS) are generated in the metabolic course of the human body, which can cause human damage when overactivated. However, whether bioallethrin evokes cytotoxicity through ROS signaling and whether the antioxidant Vitamin E (VE) protects these cytotoxic responses in human glial cell model are still elusive. This study investigated the effect of bioallethrin on cytotoxicity through ROS signaling and evaluated the protective effect of the antioxidant VE in DBTRG-05MG human glioblastoma cells. The cell counting kit-8 (CCK-8) was used to measure cell viability. Intracellular ROS and glutathione (GSH) levels were measured by a cellular assay kit. The levels of apoptosis- and antioxidant-related protein were analyzed by Western blotting. In DBTRG-05MG cells, bioallethrin (25-75 μM) concentration-dependently induced cytotoxicity by increasing ROS productions, decreasing GSH contents, and regulating protein expressions related to apoptosis or antioxidation. Furthermore, these cytotoxic effects were partially reversed by VE (20 μM) pretreatment. Together, VE partially lessened bioallethrin-induced apoptosis through oxidative stress in DBTRG-05MG cells. The data assist us in identifying the toxicological mechanism of bioallethrin and offer future development of the antioxidant VE to reduce brain damage caused by bioallethrin.

Production of a Novel Superoxide Dismutase by Escherichia coli and Pichia pastoris and Analysis of the Thermal Stability of the Enzyme

Previously, a new copper-zinc SOD (CuZnSOD) isolated from chestnut rose (Rosa roxburghii) with good stability was described. In this study, the biosynthetic approach was used to create recombinant CuZnSOD. RACE PCR was also used to amplify the full-length CuZnSOD gene from chestnut rose, and the ORF segment was expressed in E. coli BL21 and P. pastoris GS115. For characterization, the enzyme was isolated in two steps in E. coli and one step in P. pastoris. The biochemical properties of the two recombinant enzymes were similar, and their optimal reaction pH and temperature were 6.0 and 50°C, respectively. According to molecular dynamics simulation, the CuZnSOD showed high stability from 70 to 90°C, and eight amino acids are important for enzyme thermal stability at high temperatures. This study set the stage for industrial manufacture by filling gaps in the link between conformational changes and the thermal stability of the new CuZnSOD.

Molecular Mechanisms of Exercise and Healthspan

Healthspan is the period of our life without major debilitating diseases. In the modern world where unhealthy lifestyle choices and chronic diseases taper the healthspan, which lead to an enormous economic burden, finding ways to promote healthspan becomes a pressing goal of the scientific community. Exercise, one of humanity's most ancient and effective lifestyle interventions, appears to be at the center of the solution since it can both treat and prevent the occurrence of many chronic diseases. Here, we will review the current evidence and opinions about regular exercise promoting healthspan through enhancing the functionality of our organ systems and preventing diseases.

Harnessing oxidative stress for anti-glioma therapy

Glioma cells use intermediate levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) for growth and invasion, and suppressing these reactive molecules thus may compromise processes that are vital for glioma survival. Increased oxidative stress has been identified in glioma cells, in particular in glioma stem-like cells. Studies have shown that these cells harbor potent antioxidant defenses, although endogenous protection against nitrosative stress remains understudied. The enhancement of oxidative or nitrosative stress offers a potential target for triggering glioma cell death, but whether oxidative and nitrosative stresses can be combined for therapeutic effects requires further research. The optimal approach of harnessing oxidative stress for anti-glioma therapy should include the induction of free radical-induced oxidative damage and the suppression of antioxidant defense mechanisms selectively in glioma cells. However, selective induction of oxidative/nitrosative stress in glioma cells remains a therapeutic challenge, and research into selective drug delivery systems is ongoing. Because of multifactorial mechanisms of glioma growth, progression, and invasion, prospective oncological therapies may include not only therapeutic oxidative/nitrosative stress but also inhibition of oncogenic kinases, antioxidant molecules, and programmed cell death mediators.

Impact of glutathione S transferases P1 (Ile105Val) variants on the risk of GSTp, phosphorylated c-Jun kinase, and P53 phenotypic expression and their implications on overall survival outcomes in non-small cell lung cancer patients treated with chemotherapy

AIM

This study focused on GST-M1, T1 null, and P1 Ile105Val variant genotypes associated with the risk of altered expression of GSTp, pJNK, and P53 in NSCLC patients. These markers and overall survival (OS) were correlated with a key set of clinicopathological characteristics.

METHODS

Genotyping of GST- M1, T1 (+/-), and P1 (Ile105Val) was performed using PCR-RFLP.The expression of GSTp, pJNK, and P53 phenotypes was assessed by immunohistochemistry. The Spearman test was used to examine the correlation between GSTp, pJNK, and P53. Kaplan-Meier test was used for OS analysis.

RESULTS

GSTP1 Val/Val and Ile/Val genotypes notably increased GSTp expression by 1.8 and 1.7 fold, respectively (p = 0.04,p = 0.06). GSTP1 Val/Val and Ile/Val genotypes considerably reduced P53 expression by 0.61 and 0.57 fold, respectively (p = 0.03& p = 0.05), respectively. GSTp, pJNK, and P53 were significantly co-expressed (p < 0.001). GSTp and pJNK expression showed a moderate negative correlation (ρ = -0.32, p = 0.046). In contrast, GSTp and P53 expression exhibited a strong negative correlation (ρ = -0.53, p < 0.0001). There was no correlation between P53 and pJNK expression(ρ = 0.07, p = 0.54). The patient's median OS was 8.9 months, and it was significantly related to pack-years, stage, metastasis, and GSTM1(-/-) genotypes (p > 0.05). SQCLC showed poor OS than ADC (5.7 months vs.9.1 months, p = 0.2). Stage IV and metastasis significantly reduced the OS (p = 0.001). The tumour size and lymph nodes reflected poor OS (p = 0.07&p = 0.06). Gemcitabine+Cisplatin and Gefitinib showed a slightly higher rate of survival (9.3 months and 8.1 months) than Pemtrexe+Cisplatin treatment (7.0 months,p = 0.8). Multivariate analysis revealed that pack-years and GSTp were independent predictors for OS (p = 0.03).

CONCLUSION

GSTp, pJNK, and P53 showed interconnected cascading. Age, pack-year, stage, and GSTp were found to be significant predictive factors for OS.Pack-years, GSTp independent OS predictor.

Unveiling the interplay between homogeneous and heterogeneous catalytic mechanisms in copper–iron nanoparticles working under chemically relevant tumour conditions

This work studies in depth the interplay between glutathione (GSH) and a copper–iron oxide nanocatalyst. We describe the activation and interplay of homogeneous and heterogeneous processes that induce a cascade of reactions against cancer cells.

Role of Nrf2 in Pancreatic Cancer

Pancreatic tumors are a serious health problem with a 7% mortality rate worldwide. Inflammatory processes and oxidative stress play important roles in the development of pancreatic diseases/cancer. To maintain homeostasis, a balance between free radicals and the antioxidant system is essential. Nuclear Factor Erythroid 2-Related Factor 2/NFE2L2 (Nrf2) and its negative regulator Kelch-Like ECH-Associated Protein 1 (Keap1) provide substantial protection against damage induced by oxidative stress, and a growing body of evidence points to the canonical and noncanonical Nrf2 signaling pathway as a pharmacological target in the treatment of pancreatic diseases. In this review, we present updated evidence on the activation of the Nrf2 signaling pathway and its importance in pancreatic cancer. Our review covers potential modulators of canonical and noncanonical pathway modulation mechanisms that may have a positive effect on the therapeutic response. Finally, we describe some interesting recent discoveries of novel treatments related to the antioxidant system for pancreatic cancer, including natural or synthetic compounds with therapeutic properties.

Synthesis and biological evaluation of halogenated phenoxychalcones and their corresponding pyrazolines as cytotoxic agents in human breast cancer

Novel halogenated phenoxychalcones 2a–f and their corresponding N-acetylpyrazolines 3a–f were synthesised and evaluated for their anticancer activities against breast cancer cell line (MCF-7) and normal breast cell line (MCF-10a), compared with staurosporine. All compounds showed moderate to good cytotoxic activity when compared to control. Compound 2c was the most active, with IC₅₀ = 1.52 µM and selectivity index = 15.24. Also, chalcone 2f showed significant cytotoxic activity with IC₅₀ = 1.87 µM and selectivity index = 11.03. Compound 2c decreased both total mitogen activated protein kinase (p38α MAPK) and phosphorylated enzyme in MCF-7 cells, suggesting its ability to decrease cell proliferation and survival. It also showed the ability to induce ROS in MCF-7 treated cells. Compound 2c exhibited apoptotic behaviour in MCF-7 cells due to cell accumulation in G2/M phase and elevation in late apoptosis 57.78-fold more than control. Docking studies showed that compounds 2c and 2f interact with p38alpha MAPK active sites.

Trace elements under the spotlight: A powerful nutritional tool in cancer

Cancer is the second leading cause of death worldwide. Research on the relationships between trace elements (TE) and the development of cancer or its prevention is a field that is gaining increasing relevance. This review provides an evaluation of the effects of TE (As, Al, B, Cd, Cr, Cu, F, I, Pb, Li, Mn, Hg, Mo, Ni, Se, Si, Sn, V and Zn) intake and supplementation in cancer risk and prevention, as well as their interactions with oncology treatments. Advancements in the knowledge of TE, their dietary interactions and their main food sources can provide patients with choices that will help them to improve their quality of life and therapy outcomes. This approach could open new opportunities for treatments based on the integration of conventional therapies (chemotherapy, radiotherapy, and immunotherapy) and dietary interventions that provide advanced personalized treatments.