The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of various chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensue tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

Trifluoperazine exerts anti-osteosarcoma effect by inducing mitochondria-dependent apoptosis via AKT/TXNIP signaling pathway

The survival rates for patients with osteosarcoma (OS) have stagnated over the past few decades. It is essential to find new therapies and drugs. A licensed antipsychotic medication called trifluoperazine (TFP) significantly reduces the growth of several cancers. However, the exact molecular pathways of TFP in OS remain to be discovered. Our research revealed that TFP greatly reduced OS cell migration and growth and caused the arrest of G0/G1 cell cycle. Combined with RNA-Seq data and further research, we confirmed that TFP promoted reactive oxygen species (ROS) production by elevating thioredoxin binding protein (TXNIP) expression to induce mitochondria-dependent apoptosis. Interestingly, we first demonstrated that AKT was an upstream regulatory target of TXNIP in OS cells. Dephosphorylation of AKT led to an increase in TXNIP expression, further elucidating the anticancer mechanism of TFP. In vivo, TFP inhibited subcutaneous OS cell proliferation and induced OS cell apoptosis without noticeable side effects. In conclusion, our findings imply that TFP is a potential treatment for OS.

Studies related to the enhanced the effect of 5-aminolevulinic acid-based photodynamic therapy combined with tirapazamine

OBJECTIVE

5-aminolevulinic acid (5-ALA) is a precursor of the photosensitizer Protoporphyrin IX (PpIX) and photodynamic therapy (PDT) with 5-ALA has been used in clinical practice. However, tumor cellular hypoxia severely affects the efficiency of photodynamic therapy. In this study, photodynamic therapy was combined with tirapazamine to investigate the effects of the combined intervention and the related mechanisms it may involve.

METHODS

Colony formation assays were used to demonstrate cell proliferation. Transwell assays were performed to observe the effect on cell invasion and metastasis after the corresponding intervention. DCFH-DA probe was used to detect the reactive oxygen species content. Flow cytometry was used to detect the effects of the interventions on apoptosis and cell cycle. The relevant pathways that may be involved are explored by examining the expression levels of the relevant proteins and genes.

RESULTS

Colony formation assays indicated that the combined intervention inhibited cell proliferation. Transwell assays demonstrated that PDT combined with TPZ effectively inhibited tumor cell invasion and metastasis. In addition, fluorescence intensity generated by DCFH-DA oxidation was detected indicating that the combined intervention increased the formation of reactive oxygen species. Flow cytometry clearly showed that the combination of PDT and TPZ further increased apoptosis and cell cycle arrest. The results of western blotting and qRT-PCR experiments confirmed that the combination therapy inhibited HIF-1α/VEGF axis and the PI3K/Akt/mTOR pathway activation.

CONCLUSION

5-ALA-PDT combined with TPZ can inhibit cell proliferation, increase apoptosis, and inhibit the PI3K/Akt/mTOR pathway, thus inhibiting tumor growth and metastasis and improving anti-cancer effects.

Melanoma redox biology and the emergence of drug resistance

Melanoma is the deadliest form of skin cancer, with the loss of approximately 60,000 lives world-wide each year. Despite the development of targeted therapeutics, including compounds that have selectivity for mutant oncoproteins expressed only in cancer cells, many patients are either unresponsive to initial therapy or their tumors acquire resistance. This results in five-year survival rates of below 25%. New strategies that either kill drug-resistant melanoma cells or prevent their emergence would be extremely valuable. Melanoma, like other cancers, has long been described as being under increased oxidative stress, resulting in an increased reliance on antioxidant defense systems. Changes in redox homeostasis are most apparent during metastasis and during the metabolic reprogramming associated with the development of treatment resistance. This review discusses oxidative stress in melanoma, with a particular focus on targeting antioxidant pathways to limit the emergence of drug resistant cells.

Involvement of Reactive Oxygen Species in Prostate Cancer and Its Disparity in African Descendants

Reactive oxygen species (ROS) participate in almost all disorders, including cancer. Many factors, including aging, a high-fat diet, a stressful lifestyle, smoking, infection, genetic mutations, etc., lead to elevated levels of ROS. Prostate cancer, the most prevalent type of cancer in senior American men and the second leading cause of cancer mortality in American men, results from chronic oxidative stress. The doubled incident rate as well as the doubled mortality numbers of prostate cancer have persisted in African Americans in comparison with Caucasian Americans and other racial groups, indicating a prostate cancer disparity in African American men. In this review, we mainly focus on the latest findings on ROS in prostate cancer development and progression within the last five years to update our understanding in this area, as several comprehensive literature reviews addressing oxidative stress and/or inflammation in prostate cancer before 2020 are available. In addition to other known factors such as socioeconomic disadvantage, cultural mistrust of the health care system, etc. that are long-existing in the African American group, we also summarize the latest evidence that demonstrated high systemic oxidative stress and inflammation in African Americans for their potential contribution to the racial prostate cancer disparity in this population.

NOX4 regulates gastric cancer cell invasion and proliferation by increasing ferroptosis sensitivity through regulating ROS

OBJECTIVE

We assessed NOX4 expression in gastric cancer (GC), its prognostic significance, and underlying mechanisms, focusing on promoting ferroptosis through increased ROS production.

METHODS

We evaluated NOX4 expression in GC tissues via immunohistochemistry and analyzed correlations with clinicopathological characteristics using TCGA and clinical data. Impacts of manipulating NOX4 levels on GC cell invasiveness, proliferation, and sensitivity to ferroptosis inducers were investigated.

RESULTS

Significantly higher NOX4 expression in GC tissues versus normal adjacent tissues correlated with decreased overall survival and increased tumor aggressiveness. NOX4 was an independent predictor of poor prognosis. Functionally, NOX4 manipulation influenced ROS levels, with overexpression enhancing production. Inhibition of NOX4 or application of antioxidants reduced cancer cell invasion and proliferation. Importantly, NOX4-overexpressing cells showed increased sensitivity to ferroptosis inducers, indicating synergistic effects between NOX4 and ferroptosis in suppressing GC progression.

CONCLUSION

Our findings highlight NOX4's potential as a therapeutic target in GC, where modulation can enhance efficacy of ferroptosis-inducing treatments, offering a promising strategy for combating this malignancy.

Inositol Hexaphosphate as an Inhibitor and Potential Regulator of p47phox Membrane Anchoring

As a key component for NADPH oxidase 2 (NOX2) activation, the peripheral membrane protein p47phox translocates a cytosolic activating complex to the membrane through its PX domain. This study elucidates a potential regulatory mechanism of p47phox recruitment and NOX2 activation by inositol hexaphosphate (IP6). Through NMR, fluorescence polarization, and FRET experimental results, IP6 is shown to be capable of breaking the lipid binding and membrane anchoring events of p47phox-PX with low micromolar potency. Other phosphorylated inositol species such as IP5(1,3,4,5,6), IP4(1,3,4,5), and IP3(1,3,4) show weaker binding and no ability to inhibit lipid interactions in physiological concentration ranges. The low micromolar potency of IP6 inhibition of the p47phox membrane anchoring suggests that physiologically relevant concentrations of IP6 serve as regulators, as seen in other membrane anchoring domains. The PX domain of p47phox is known to be promiscuous to a variety of phosphatidylinositol phosphate (PIP) lipids, and this regulation may help target the domain only to the membranes most highly enriched with the highest affinity PIPs, such as the phagosomal membrane, while preventing aberrant binding to other membranes with high and heterogeneous PIP content, such as the plasma membrane. This study provides insight into a potential novel regulatory mechanism behind NOX2 activation and reveals a role for small-molecule regulation in this important NOX2 activator.

NADPH Oxidase-Like Nanozyme for High-Efficiency Tumor Therapy Through Increasing Glutathione Consumption and Blocking Glutathione Regeneration

To counteract the high level of reactive oxygen species (ROS) caused by rapid growth, tumor cells resist oxidative stress by accelerating the production and regeneration of intracellular glutathione (GSH). Numerous studies focus on the consumption of GSH, but the regeneration of GSH will enhance the reduction level of tumor cells to resist oxidative stress. Therefore, inhibiting the regeneration of GSH; while, consuming GSH is of great significance for breaking the redox balance of tumor cells. Herein, a simple termed MnOx-coated Au (AMO) nanoflower, as a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) nanoenzyme, is reported for efficient tumor therapy. Au nanoparticles exhibit the capability to catalyze the oxidation of NADPH, hindering GSH regeneration; while, concurrently functioning as a photothermal agent. During the process of eliminating intracellular GSH, MnOx releases Mn2+ that subsequently engages in Fenton-like reactions, ultimately facilitating the implementation of chemodynamic therapy (CDT). Overall, this NOX enzyme-based nanoplatform enhances ROS generation and disrupts the state of reduction equilibrium, inducing apoptosis and ferroptosis by blocking GSH regeneration and increasing GSH consumption, thereby achieving collaborative treatments involving photothermal therapy (PTT), CDT, and catalytic therapy. This research contributes to NADPH and GSH targeted tumor therapy and showcases the potential of nanozymes.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Menadione and protocatechuic acid: A drug combination with antitumor effects in murine osteosarcoma cells

Osteosarcoma (OS) is a primary malignant bone tumor that has an abnormal expression of oncogenesis and tumor suppressors and causes dysregulation of various signaling pathways. Thus, novel therapeutic strategies for OS are needed to overcome the resistance of traditional treatments. This study evaluated the cytotoxic and anticancer effects of the association between menadione (MEN) and protocatechuic acid (PCA) in murine OS cells (UMR-106). The concentrations were 3.12 μM of isolated MEN, 500 μM of isolated PCA, and their associations. We performed cell viability assays, morphology modification analysis, cell migration by the wound-healing method, apoptosis by flow cytometry, reactive oxygen species (ROS) production, gene expression of NOX by RT-qPCR, and degradation of MMP-2 and 9 by zymography. Our results showed that the association of MEN+PCA was more effective in OS cells than the compounds alone. The association decreased cell viability, delayed cell migration, and decreased the expression of NOX-2 and ROS. In addition, the MEN+PCA association induced a slight increase in the apoptotic process. In summary, the association can enhance the compound's antitumor effects and establish a higher selectivity for tumor cells, possibly caused by significant mitochondrial damage and antioxidant properties.

New phenothiazine conjugates as apoptosis inducing agents: Design, synthesis, In-vitro anti-cancer screening and 131I-radiolabeling for in-vivo evaluation

Phenothiazines (PTZs) are a group of compounds characterized by the presence of the 10H-dibenzo-[b,e]-1,4-thiazine system. PTZs used in clinics as antipsychotic drugs with other diverse biological activities. The current aim of the study is to investigate and understand the effect of potent PTZs compounds using a group of In-vitro and In-vivo assays. A total of seventeen novel phenothiazine derivatives have been designed, synthesized, and evaluated primarily in-vitro for their ability to inhibit proliferation activity against NCI-60 cancer cell lines, including several multi-drug resistant (MDR) tumor cell lines. Almost all compounds were active and displayed promising cellular activities with GI50 values in the sub-micromolar range. Four of the most promising derivatives (4b, 4h, 4g and 6e) have been further tested against two selected sensitive cancer cell lines (colon cancer; HCT-116 and breast cancer; MDA-MB231). The apoptosis assay showed that all the selected compounds were able to induce early apoptosis and compound 6e was able to induce additional cellular necrosis. Cell cycle assay showed all selected compounds were able to induce cell cycle arrest at sub-molecular phase of G0-G1 with compound 6e induced cell cycle arrest at G2M in HCT-116 cells. Accordingly, the apoptotic effect of the selected compounds was extensively investigated on genetic level and Casp-3, Casp-9 and Bax gene were up-regulated with down-regulation of Bcl-2 gene suggesting the activation of both intrinsic and extrinsic pathways. In-vivo evaluation of the antitumor activity of compound 4b in solid tumor bearing mice showed promising therapeutic effect with manifestation of dose and time dependent toxic effects at higher doses. For better evaluation of the degree of localization of 4b, its 131I-congener (131I-4b) was injected intravenously in Ehrlich solid tumor bearing mice that showed good localization at tumor site with rapid distribution and clearance from the blood. In-silico study suggested NADPH oxidases (NOXs) as potential molecular target. The compounds introduced in the current study work provided a cutting-edge phenothiazine hybrid scaffold with promising anti-proliferation action that may suggest their anti-cancer activity.

Comprehensive analysis and identification of prognostic biomarkers and immunotherapeutic targets in the NADPH oxidase family (and its regulatory subunits) in pancreatic ductal adenocarcinoma

PURPOSE

This study aimed to evaluate the role of NADPH in pancreatic ductal adenocarcinoma using bioinformatic analyses and experimental validations.

METHODS

We compared the expression levels, performed GO and KEGG analysis of NADPH oxidase family and its regulatory subunits, and determined the survival of patients with pancreatic ductal adenocarcinoma by GEPIA, David and KM plotter. The relationship between their expression with immune infiltration levels, phagocytotic/NK cell immune checkpoints, recruitment-related molecules were detected by Timer 2.0 and TISIDB, respectively. Subsequently, their correlation with NK cell infiltration level was verified by immunohistochemistry.

RESULTS

The expression of some members of the NADPH oxidase family and its regulatory subunits was significantly increased in pancreatic ductal adenocarcinoma tissues compared to that in normal tissues and was positively correlated with natural killer (NK) cell infiltration. Furthermore, the NADPH oxidase family and its regulatory subunits were associated with survival and immune status in patients with pancreatic ductal adenocarcinoma, including chemokines, immune checkpoints, and immune infiltration levels of NK cells, monocytes, and myeloid-derived suppressor cells.

CONCLUSIONS

These results suggest the NADPH oxidase family and its regulatory subunits might serve as indicators for predicting the responsiveness to immunotherapy and outcome of patients with pancreatic ductal adenocarcinoma, providing a new perspective or strategy for immunotherapy in pancreatic ductal adenocarcinoma.

Anti-proliferative effect of Cannabidiol in Prostate cancer cell PC3 is mediated by apoptotic cell death, NFκB activation, increased oxidative stress, and lower reduced glutathione status

Prostate cancer is the second most frequent cancer diagnosed in men in the world today. Almost all prostate cancers are adenocarcinomas and develop from gland cells. We used the PC3 prostate cancer cell line, which is well studied and derived from a bone metastasis of a grade IV prostatic adenocarcinoma. Cannabidiol (CBD), a major non-psychoactive constituent of cannabis, is a cannabinoid with anti-tumor properties but its effects on prostate cancer cells are not studied in detail. Here, we found cannabidiol decreased prostate cancer cell (PC3) viability up to 37.25% and induced apoptotic cell death in a time and dose-dependent manner. We found that CBD activated the caspases 3/7 pathways and increased DNA fragmentation. Furthermore, we observed an increase of pro-apoptotic genes Bax, an increased level of reactive oxygen species, lower reduced glutathione level, and altered mitochondrial potential in response to CBD treatment leading to lower cellular ATP. Overall, our results suggest that CBD may be effective against prostate cancer cells.

NADPH Oxidases: From Molecular Mechanisms to Current Inhibitors

NADPH oxidases (NOXs) form a family of electron-transporting membrane enzymes whose main function is reactive oxygen species (ROS) generation. Strong evidence suggests that ROS produced by NOX enzymes are major contributors to oxidative damage under pathologic conditions. Therefore, blocking the undesirable actions of these enzymes is a therapeutic strategy for treating various pathological disorders, such as cardiovascular diseases, inflammation, and cancer. To date, identification of selective NOX inhibitors is quite challenging, precluding a pharmacologic demonstration of NOX as therapeutic targets in vivo. The aim of this Perspective is to furnish an updated outlook about the small-molecule NOX inhibitors described over the last two decades. Structures, activities, and in vitro/in vivo specificity are discussed, as well as the main biological assays used.

Pepper Fruit Extracts Show Anti-Proliferative Activity against Tumor Cells Altering Their NADPH-Generating Dehydrogenase and Catalase Profiles

Cancer is considered one of the main causes of human death worldwide, being characterized by an alteration of the oxidative metabolism. Many natural compounds from plant origin with anti-tumor attributes have been described. Among them, capsaicin, which is the molecule responsible for the pungency in hot pepper fruits, has been reported to show antioxidant, anti-inflammatory, and analgesic activities, as well as anti-proliferative properties against cancer. Thus, in this work, the potential anti-proliferative activity of pepper (Capsicum annuum L.) fruits from diverse varieties with different capsaicin contents (California < Piquillo < Padrón < Alegría riojana) against several tumor cell lines (lung, melanoma, hepatoma, colon, breast, pancreas, and prostate) has been investigated. The results showed that the capsaicin content in pepper fruits did not correspond with their anti-proliferative activity against tumor cell lines. By contrast, the greatest activity was promoted by the pepper tissues which contained the lowest capsaicin amount. This indicates that other compounds different from capsaicin have this anti-tumor potentiality in pepper fruits. Based on this, green fruits from the Alegría riojana variety, which has negligible capsaicin levels, was used to study the effect on the oxidative and redox metabolism of tumor cell lines from liver (Hep-G2) and pancreas (MIA PaCa-2). Different parameters from both lines treated with crude pepper fruit extracts were determined including protein nitration and protein S-nitrosation (two post-translational modifications (PTMs) promoted by nitric oxide), the antioxidant capacity, as well as the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX), among others. In addition, the activity of the NADPH-generating enzymes glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and NADP-isocitrate dehydrogenase (NADP-ICDH) was followed. Our data revealed that the treatment of both cell lines with pepper fruit extracts altered their antioxidant capacity, enhanced their catalase activity, and considerably reduced the activity of the NADPH-generating enzymes. As a consequence, less H₂O₂ and NADPH seem to be available to cells, thus avoiding cell proliferation and possibly triggering cell death in both cell lines.

Development and validation of an oxidative stress‑related prognostic signature in osteosarcoma: A combination of molecular experiments and bioinformatics

Osteosarcoma (OS) is one of the most prevalent malignancies with a bad prognosis. Oxidative stress is closely associated with various type of cancer. The present study aimed to establish an oxidative stress-related gene prognostic signature. Supported by The Cancer Genome Atlas and Gene Expression Omnibus, the least absolute shrinkage and selection operator regression, Cox regression, receiver operating characteristic curves and Kaplan-Meier survival analysis were used to construct and validate a prognostic signature and the derived risk score. Tumor microenvironment scores and immune infiltration levels in OS were calculated. Correlation between these parameters and risk score was analyzed. In addition, single analysis of each hub gene was performed. Finally, a series of molecular experiments was used to detect the role of MAP3K5 (one of the hub genes) in OS. A total of five genes most associated with OS prognosis were identified as independent predictors, namely catalase (CAT), mitogen-activated protein kinase 1 (MAPK1), glucose-6-phosphate dehydrogenase (G6PD), mitogen-activated protein kinase kinase kinase 5 (MAP3K5) and C-C motif chemokine ligand 2 (CCL2). Based on the signature, higher risk score indicated poorer prognosis. Nomogram performed well and reliably predicted 3- and 5-year survival rate in OS. Patients with increasing risk scores had higher tumor purity and lower immune infiltration levels. Compared with an osteoblast cell line, the expression of CAT, CCL2, MAPK1 and G6PD was upregulated and MAP3K5 was downregulated. MAP3K5 inhibited cellular proliferation and motility, promoted cellular apoptosis and induced reactive oxygen species generation. Overall, the signature could effectively predict the prognosis of patients with OS and were expected to be potential biomarkers. And it provided new ideas for understanding the interactions between oxidative stress and OS.

Integrated bioinformatics identifies key mediators in cytokine storm and tissue remodeling during Vibrio mimicus infection in yellow catfish (Pelteobagrus fulvidraco)

Introduction

The pathogenesis of Vibrio mimicus infection in yellow catfish (Pelteobagrus fulvidraco) remains poorly understood, particularly regarding the impact of infection with the pathogen on primary target organs such as the skin and muscle.

Methods

In this study, we aim to analyze the pathological intricacies of the skin and muscle of yellow catfish after being infected with V. mimicus using a 1/10 LC₅₀ seven-day post-infection model. Furthermore, we have utilized integrated bioinformatics to comprehensively elucidate the regulatory mechanisms and identify the key regulatory genes implicated in this phenomenon.

Results

Our histopathological examination revealed significant pathological changes in the skin and muscle, characterized by necrosis and inflammation. Moreover, tissue remodeling occurred, with perimysium degeneration and lesion invasion into the muscle along the endomysium, accompanied by a transformation of type I collagen into a mixture of type I and type III collagens in the perimysium and muscle bundles. Our eukaryotic transcriptomic and 4D label-free analyses demonstrated a predominantly immune pathway response in both the skin and muscle, with downregulation observed in several cell signaling pathways that focused on focal adhesion-dominated cell signaling pathways. The upregulated genes included interleukins (IL)-1 and -6, chemokines, and matrix metallopeptidases (mmp)-9 and -13, while several genes were significantly downregulated, including col1a and col1a1a. Further analysis revealed that these pathways were differentially regulated, with mmp-9 and mmp-13 acting as the potential core regulators of cytokine and tissue remodeling pathways. Upregulation of NF-κB1 and FOSL-1 induced by IL-17C and Nox 1/2-based NADPH oxidase may have held matrix metallopeptidase and cytokine-related genes. Also, we confirmed these relevant regulatory pathways by qPCR and ELISA in expanded samples.

Discussion

Our findings unequivocally illustrate the occurrence of a cytokine storm and tissue remodeling, mediated by interleukins, chemokines, and MMPs, in the surface of yellow catfish infected with V. mimicus. Additionally, we unveil the potential bidirectional regulatory role of MMP-9 and MMP-13. These results provide novel perspectives on the intricate immune response to V. mimicus infection in yellow catfish and highlight potential targets for developing therapies.

Multi-omic profiling reveals an RNA processing rheostat that predisposes to prostate cancer

Prostate cancer is the most commonly diagnosed malignancy and the third leading cause of cancer deaths. GWAS have identified variants associated with prostate cancer susceptibility; however, mechanistic and functional validation of these mutations is lacking. We used CRISPR-Cas9 genome editing to introduce a missense variant identified in the ELAC2 gene, which encodes a dually localised nuclear and mitochondrial RNA processing enzyme, into the mouse Elac2 gene as well as to generate a prostate-specific knockout of Elac2. These mutations caused enlargement and inflammation of the prostate and nodule formation. The Elac2 variant or knockout mice on the background of the transgenic adenocarcinoma of the mouse prostate (TRAMP) model show that Elac2 mutation with a secondary genetic insult exacerbated the onset and progression of prostate cancer. Multiomic profiling revealed defects in energy metabolism that activated proinflammatory and tumorigenic pathways as a consequence of impaired noncoding RNA processing and reduced protein synthesis. Our physiologically relevant models show that the ELAC2 variant is a predisposing factor for prostate cancer and identify changes that underlie the pathogenesis of this cancer.

Structure, regulation, and physiological functions of NADPH oxidase 5 (NOX5)

NOX5 is the last member of the NADPH oxidase (NOXs) family to be identified and presents some specific characteristics differing from the rest of the NOXs. It contains four Ca²⁺ binding domains at the N-terminus and its activity is regulated by the intracellular concentration of Ca²⁺. NOX5 generates superoxide (O₂^•-) using NADPH as a substrate, and it modulates functions related to processes in which reactive oxygen species (ROS) are involved. Those functions appear to be detrimental or beneficial depending on the level of ROS produced. For example, the increase in NOX5 activity is related to the development of various oxidative stress-related pathologies such as cancer, cardiovascular, and renal diseases. In this context, pancreatic expression of NOX5 can negatively alter insulin action in high-fat diet-fed transgenic mice. This is consistent with the idea that the expression of NOX5 tends to increase in response to a stimulus or a stressful situation, generally causing a worsening of the pathology. On the other hand, it has also been suggested that it might have a positive role in preparing the body for metabolic stress, for example, by inducing a protective adipose tissue adaptation to the excess of nutrients supplied by a high-fat diet. In this line, its endothelial overexpression can delay lipid accumulation and insulin resistance development in obese transgenic mice by inducing the secretion of IL-6 followed by the expression of thermogenic and lipolytic genes. However, as NOX5 gene is not present in rodents and human NOX5 protein has not been crystallized, its function is still poorly characterized and further extensive research is required.

Innovative nanotheranostics: Smart nanoparticles based approach to overcome breast cancer stem cells mediated chemo- and radioresistances

The alarming increase in the number of breast cancer patients worldwide and the increasing death rate indicate that the traditional and current medicines are insufficient to fight against it. The onset of chemo- and radioresistances and cancer stem cell-based recurrence make this problem harder, and this hour needs a novel treatment approach. Competent nanoparticle-based accurate drug delivery and cancer nanotheranostics like photothermal therapy, photodynamic therapy, chemodynamic therapy, and sonodynamic therapy can be the key to solving this problem due to their unique characteristics. These innovative formulations can be a better cargo with fewer side effects than the standard chemotherapy and can eliminate the stability problems associated with cancer immunotherapy. The nanotheranostic systems can kill the tumor cells and the resistant breast cancer stem cells by novel mechanisms like local hyperthermia and reactive oxygen species and prevent tumor recurrence. These theranostic systems can also combine with chemotherapy or immunotherapy approaches. These combining approaches can be the future of anticancer therapy, especially to overcome the breast cancer stem cells mediated chemo- and radioresistances. This review paper discusses several novel theranostic systems and smart nanoparticles, their mechanism of action, and their modifications with time. It explains their relevance and market scope in the current era. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Oxygen therapy accelerates apoptosis induced by selenium compounds via regulating Nrf2/MAPK signaling pathway in hepatocellular carcinoma

Selenium has good antitumor effects in vitro, but the hypoxic microenvironment in solid tumors makes its clinical efficacy unsatisfactory. We hypothesized that the combination with oxygen therapy might improve the treatment efficacy of selenium in hypoxic tumors through the changes of redox environment. In this work, two selenium compounds, Na₂SeO₃ and CysSeSeCys, were selected to interrogate their therapeutic effects on hepatocellular carcinoma (HCC) under different oxygen levels. In tumor-bearing mice, both selenium compounds significantly inhibited the tumor growth, and combined with oxygen therapy further reduced the tumor volume about 50 %. In vitro HepG2 cell experiments, selenium induced autophagy and delayed apoptosis under hypoxia (1 % O₂), while inhibited autophagy and accelerated apoptosis under hyperoxia (60 % O₂). We found that, in contrast to hypoxia, the hyperoxic environment facilitated the H₂Se, produced by the selenium metabolism in cells, to be rapidly oxidized to generate H₂O₂, leading to inhibit the expression level of Nrf2 and to increase that of phosphorylation of p38 and MKK4, resulting in inhibiting autophagy and accelerating apoptosis. Once the Nrf2 gene was knocked down, selenium compounds combined with hyperoxia treatment would further activate the MAPK signaling pathway and further increase apoptosis. These findings highlight oxygen can significantly enhance the anti-HCC effect of selenium compounds through regulating the Nrf2 and MAPK signaling pathways, thus providing novel therapeutic strategy for the hypoxic tumors and pave the way for the application of selenium in clinical treatment.

Inhibition of NADPH Oxidase-ROS Signal using Hyaluronic Acid Nanoparticles for Overcoming Radioresistance in Cancer Therapy

Upregulation of NADPH oxidases (NOXs) in cancer cells leads to chronic increase in intracellular reactive oxygen species (ROS) and adaptation to a high ROS level for cell survival and, thereby, low sensitivity to radiotherapy. To overcome resistance to radiotherapy, we have developed a bioactive and CD44 targeted hyaluronic acid nanoparticle encapsulated with an NOX inhibitor, GKT831 (HANP/GKT831). We found that HANP/GKT831 had stronger inhibitory effects on ROS generation and cell proliferation than that of GKT831 alone in cancer cells. Systemic delivery of HANP/GKT831 led to the targeted accumulation in breast cancer patient derived xenograft (PDX) tumors in nude mice. Importantly, the combination of systemic delivery of HANP/GKT831 with a low dose of local radiotherapy significantly enhanced tumor growth inhibition in breast cancer PDX models. Our results showed that HANP/GKT831 primed tumor cells to radiation-induced DNA damage and cell death by downregulation of DNA repair function and oncogenic signal pathways.

Oxidized Proteins Differentially Affect Maturation and Activation of Human Monocyte-Derived Cells

In cancer, antigen-presenting cells (APC), including dendritic cells (DCs), take up and process proteins to mount adaptive antitumor immune responses. This often happens in the context of inflamed cancer, where reactive oxygen species (ROS) are ubiquitous to modify proteins. However, the inflammatory consequences of oxidized protein uptake in DCs are understudied. To this end, we investigated human monocyte-derived cell surface marker expression and cytokine release profiles when exposed to oxidized and native proteins. Seventeen proteins were analyzed, including viral proteins (e.g., CMV and HBV), inflammation-related proteins (e.g., HO1 and HMGB1), matrix proteins (e.g., Vim and Coll), and vastly in the laboratory used proteins (e.g., BSA and Ova). The multifaceted nature of inflammation-associated ROS was mimicked using gas plasma technology, generating reactive species cocktails for protein oxidation. Fourteen oxidized proteins led to elevated surface marker expression levels of CD25, CD40, CD80, CD86, and MHC-II as well as strongly modified release of IL6, IL8, IL10, IL12, IL23, MCP-1, and TNFα compared to their native counterparts. Especially IL8, heme oxygenase 2, and vimentin oxidation gave pronounced effects. Furthermore, protein kinase phospho-array studies in monocyte-derived cells pulsed with native vs. oxidized IL8 and insulin showed enhanced AKT and RSK2 phosphorylation. In summary, our data provide for the first time an overview of the functional consequences of oxidized protein uptake by human monocyte-derived cells and could therefore be a starting point for exploiting such principle in anticancer therapy in the future.

Targeting Mitochondrial Metabolism to Reverse Radioresistance: An Alternative to Glucose Metabolism

Radiotherapy failure and poor tumor prognosis are primarily attributed to radioresistance. Improving the curative effect of radiotherapy and delaying cancer progression have become difficult problems for clinicians. Glucose metabolism has long been regarded as the main metabolic process by which tumor cells meet their bioenergetic and anabolic needs, with the complex interactions between the mitochondria and tumors being ignored. This misconception was not dispelled until the early 2000s; however, the cellular molecules and signaling pathways involved in radioresistance remain incompletely defined. In addition to being a key metabolic site that regulates tumorigenesis, mitochondria can influence the radiation effects of malignancies by controlling redox reactions, participating in oxidative phosphorylation, producing oncometabolites, and triggering apoptosis. Therefore, the mitochondria are promising targets for the development of novel anticancer drugs. In this review, we summarize the internal relationship and related mechanisms between mitochondrial metabolism and cancer radioresistance, thus exploring the possibility of targeting mitochondrial signaling pathways to reverse radiation insensitivity. We suggest that attention should be paid to the potential value of mitochondria in prolonging the survival of cancer patients.

Dietary Vitamin A Intake and Circulating Vitamin A Concentrations and the Risk of Three Common Cancers in Women: A Meta-Analysis

BACKGROUND

According to relevant clinical research, dietary and circulating antioxidants vitamin A are connected with the risk of breast, cervical, and ovarian cancer in women. However, there was inconsistency between the findings. We completed this meta-analysis at the right moment to address this contradiction of the problem.

METHODS

Web of Science, Embase, and PubMed databases were searched using the proposed search strategy and filtered using the inclusion and exclusion criteria as well as the NOS quality score. As of May 2022, low intake or low concentration was used as a control, and odds ratio (OR) or relative risk (RR) and ninety-five percent confidence intervals (95% CI) were extracted for high intake. Stata 12.0 was used to process the data.

RESULTS

Our meta-analysis included a total of 49 studies, 29 on breast cancer, 10 on ovarian cancer, and 10 on cervical cancer. There were 38 case-control studies included, with 25,363 cases and 42,281 controls; there were 11 cohort studies included, 1,334,176 individuals were followed up, and finally 9496 obtained cancer. The pooled OR value results were as follows: diet or supplements (OR = 0.83, 95% CI 0.76-0.90, I ² = 56.1%) and serum or plasma (OR = 0.96, 95% CI 0.86-1.09, I ² = 29.5%). Subgroup analyses were performed according to cancer type, diet or supplements, serum or plasma, study type, and geographic regions.

CONCLUSIONS

In North American and Asian populations, high dietary consumption of vitamin A or supplements decreases the incidence of three cancers in women, with breast and ovarian cancers being more significant. However, high circulating vitamin A concentrations were not significantly connected with the risk of the three malignancies.

NOX as a Therapeutic Target in Liver Disease

The nicotinamide adenine dinucleotide phosphate hydrogen oxidase (NADPH oxidase or NOX) plays a critical role in the inflammatory response and fibrosis in several organs such as the lungs, pancreas, kidney, liver, and heart. In the liver, NOXs contribute, through the generation of reactive oxygen species (ROS), to hepatic fibrosis by acting through multiple pathways, including hepatic stellate cell activation, proliferation, survival, and migration of hepatic stellate cells; hepatocyte apoptosis, enhancement of fibrogenic mediators, and mediation of an inflammatory cascade in both Kupffer cells and hepatic stellate cells. ROS are overwhelmingly produced during malignant transformation and hepatic carcinogenesis (HCC), creating an oxidative microenvironment that can cause different and various types of cellular stress, including DNA damage, ER stress, cell death of damaged hepatocytes, and oxidative stress. NOX1, NOX2, and NOX4, members of the NADPH oxidase family, have been linked to the production of ROS in the liver. This review will analyze some diseases related to an increase in oxidative stress and its relationship with the NOX family, as well as discuss some therapies proposed to slow down or control the disease's progression.

Modulation of Reactive Oxygen Species in Cancers: Recent Advances

Oxidation-reduction reactions played a significant role in the chemical evolution of life forms on oxygenated earth. Cellular respiration is dependent on such redox reactions, and any imbalance leads to the accumulation of reactive oxygen species (ROS), resulting in both chronic and acute illnesses. According to the International Agency for Research on Cancer (IARC), by 2040, the global burden of new cancer cases is expected to be around 27.5 million, with 16.3 million cancer deaths due to an increase in risk factors such as unhealthy lifestyle, environmental factors, aberrant gene mutations, and resistance to therapies. ROS play an important role in cellular signalling, but they can cause severe damage to tissues when present at higher levels. Elevated and chronic levels of ROS are pertinent in carcinogenesis, while several therapeutic strategies rely on altering cellular ROS to eliminate tumour cells as they are more susceptible to ROS-induced damage than normal cells. Given this selective targeting potential, therapies that can effectively modulate ROS levels have been the focus of intense research in recent years. The current review describes biologically relevant ROS, its origins in solid and haematological cancers, and the current status of evolving antioxidant and pro-oxidant therapies in cancers.

The Janus-faced role of TRPM2-S in retroperitoneal liposarcoma via increasing ROS levels

BACKGROUND

Retroperitoneal liposarcoma (RPLS) is a specific soft tissue sarcoma with a high recurrence rate. The short isoform of transient receptor potential cation channel subfamily M member 2 (TRPM2-S) plays an important role in the regulation of reactive oxygen species (ROS). However, the association between TRPM2-S and RPLS and its underlying mechanisms remains unclear.

METHODS

The expression of both TRPM2-S and TRPM2-L in RPLS tissues was verified by kimmunohistochemistry (IHC). The regulation on Ca²⁺ influx by TRPM2-S was evaluated by Fluo-4 AM staining. The effect of TRPM2-S on cell proliferation and apoptosis was tested by 5-Ethynyl-2'-deoxyuridine (EdU) staining and Flow cytometry respectively. The level of cellular ROS was assessed by the DCFH-DA probe. Different concentrations of H₂O₂ were used to provide oxidative stress on RPLS cells. The underlying mechanisms were further explored by Western blotting.

RESULTS

The IHC assays showed that TRPM2-S, but not TRPM2-L, was prognostic in RPLS. Low TRPM2-S level was associated with poor disease-free survival (DFS). Calcium influx signal intensity was significantly decreased under TRPM2-S overexpression, which resulted in a decrease in the levels of FOXO3a and PTEN. Correspondingly, the levels of pERK, pAKT, pP65, pGSK-3β, Bcl-2, and β-catenin were upregulated, and cellular ROS was gently increased under TRPM2-S overexpression. Moreover, TRPM2-S slightly promoted cell proliferation and inhibited apoptosis of RPLS cell lines under normoxia, but largely increased apoptosis rates under oxidative stress. The cleaved caspase3 was significantly upregulated by TRPM2-S overexpression under oxidative stress. N-Acetyl-L-cysteine (NAC), a small molecule antioxidant, could largely rescue RPLS cells from the apoptosis induced by H₂O₂.

CONCLUSION

TRPM2-S exerts Janus-faced effects in RPLS by increasing the ROS levels via inhibition on FOXO3a, which promotes cell proliferation under normoxia but induces apoptosis under oxidative stress. Video abstract.

Proteomics Insights into the Gene Network of cis9, trans11-Conjugated Linoleic Acid Biosynthesis in Bovine Mammary Gland Epithelial Cells

The objective of the study was to elucidate the stearoyl-coenzyme A desaturase (SCD1)-dependent gene network of c9, t11-CLA biosynthesis in MAC-T cells from an energy metabolism perspective. The cells were divided into the CAY group (firstly incubated with CAY10566, a chemical inhibitor of SCD1, then incubated with trans-11-octadecenoic acid, (TVA)), the TVA group (only TVA), and the control group (without CAY, TVA). The c9, t11-CLA, and TVA contents were determined by gas chromatography. The mRNA levels of SCD1 and candidate genes were analyzed via real-time PCR. Tandem mass tag (TMT)-based quantitative proteomics, bioinformatic analysis, parallel reaction monitoring (PRM), and small RNA interference were used to explore genes involved in the SCD1-dependent c9, t11-CLA biosynthesis. The results showed that the SCD1 deficiency led by CAY10566 blocked the biosynthesis of c9, t11-CLA. In total, 60 SCD1-related proteins mainly involved in energy metabolism pathways were primarily screened by TMT-based quantitative proteomics analysis. Moreover, 17 proteins were validated using PRM analysis. Then, 11 genes were verified to have negative relationships with SCD1 after the small RNA interference analysis. Based on the above results, we concluded that genes involved in energy metabolism pathways have an impact on the SCD1-dependent molecular mechanism of c9, t11-CLA biosynthesis.

Antiaging effect of inotodiol on oxidative stress in human dermal fibroblasts

Oxidative damage is one of the major causes of human skin aging. Inotodiol is a lanostane triterpenoid that demonstrates antiviral, anticancer, and anti-inflammatory activities. Previous studies have reported that inotodiol also has antiallergic effects. However, whether inotodiol inhibits oxidative stress-induced human skin aging is not known. Stimulation of human dermal fibroblast cells with hydrogen peroxide is related to skin aging. Inotodiol inhibited the expression of mitogen-activated protein kinase (MAPK) and NADPH Oxidase 5 (NOX5). Moreover, inotodiol effectively decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), as well as nitric oxide (NO), reactive oxygen species (ROS), cyclooxygenase-2 (COX-2), and cytokines such as IL-1β, IL-6, and TNF-α. Based on our results, inotodiol protects human dermal fibroblast by preventing MAPK-NOX5 and NF-κB activation and attenuates the expression of aging genes. Inotodiol may therefore be considered a potential candidate for developing natural antiaging products, because it protects the human skin from oxidative stress-induced skin aging by inhibiting the MAPK-NOX5 and NF-κB signaling pathways.

IL6 Induces mtDNA Leakage to Affect the Immune Escape of Endometrial Carcinoma via cGAS-STING

Endometrial carcinoma (EC) is a commonly diagnosed gynecological malignancy. Interleukin-6 (IL6) plays a critical role in modulating the progression of several types of tumors, including EC. However, the specific mechanism of IL6 in regulating EC progression has not been clearly elucidated. In this study, we performed a series of functional experiments to explore the potential mechanisms involved in IL6 function in the progression of EC. Here, we found that IL6 increased reactive oxygen species (ROS) generation by enhancing the NADPH oxidase (NOX) level and induced mtDNA leakage in EC cells, which further caused the activation of the downstream cGAS-STING signaling and increased production of extracellular vesicle (EV) production from EC cells. Besides, the activation of cGAS-STING signaling enhanced the expression of type I IFN and its downstream molecule PD-L1 through the TBK1-IRF3 pathway. Importantly, a high level mtDNA and PD-L1 were present in EVs derived from IL6-induced EC cells; these vesicles were shown to be able to induce T cell apoptosis. Finally, anti-PD-L1 treatment in mice showed that blockade of PD-L1 significantly reversed tumor immune escape mediated by IL6-induced EVs. Together, we provide evidence that IL6 induced mtDNA leakage to regulate the immune escape of EC cells. Our findings may provide a novel clue for the development of therapeutic targets for EC.

The dimerization of methyl vanillate improves its effect against breast cancer cells via pro-oxidant effect

Phenolic phytochemicals are a group of organic compounds with potent antioxidant features but can also act as powerful pro-oxidants. These characteristics are effective in reducing metastatic potential in cancer cells, and this effect has been associated with reactive oxygen species (ROS). Methyl vanillate (MV) and its dimer, methyl divanillate (DMV), are potent antioxidants. In the present study, we investigated the effects of MV and DMV on breast cancer cell lines MCF-7 and MDA-MB-231 and compared the results using the non-tumor cell line HB4a. Our results indicated that the compounds performed a pro-oxidant action, increasing the generation of ROS. DMV decreased the viability cell, showing a higher apoptotic effect and inhibition of proliferation than MV on both cell lines, with significant differences between groups (p < 0.05). Some modulation of NOX4, NOX5, and DUOX were observed, but the results did not correlate with the intracellular production of ROS. The dimer showed more effectivity and pro-oxidant effect than MV, impacting cell line MCF-7 in higher extension than MDA-MB-231. In conclusion, and corroborating with reported works, the dimerization of natural phenolic compounds was associated with improved beneficial biological effects as a potential cytotoxic agent to tumor cells.

Oxidative Stress and Redox-Dependent Signaling in Prostate Cancer

Tumor emergence and progression is complicated by the dual role of reactive oxygen species (ROS). Low concentrations of ROS are essential for many intracellular metabolic processes and cell proliferation, while excessive ROS generation disrupts the mechanisms of cancer suppression, leading to the cell damage and death. A long-term imbalance in the ROS/antioxidant ratio and upregulation of the ROS generation due to the reduced efficacy of the antioxidant defense system cause chronic oxidative stress resulting in the damage of proteins, lipid, and DNA molecules and cancer development. Numerous data demonstrate that prostate cancer (the most common cancer in males) is associated with the development of oxidative stress. However, the reasons for the emergence of prostate cancer, as well as changes in the redox signaling and cellular redox homeostasis in this disease, are still poorly understood. The review examines the role of prooxidant and antioxidant enzyme systems, the imbalance in their activity leading to the oxidative stress development, changes in the key components of redox signaling, and the role of microRNAs in the modulation of redox status of cancer cells in prostate cancer.

Cell cycle-related genes associate with sensitivity to hydrogen peroxide-induced toxicity

Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) are well-described agents in physiology and pathology. Chronic inflammation causes incessant H2O2 generation associated with disease occurrences such as diabetes, autoimmunity, and cancer. In cancer, conditioning of the tumor microenvironment, e.g., hypoxia and ROS generation, has been associated with disease outcomes and therapeutic efficacy. Many reports have investigated the roles of the action of H2O2 across many cell lines and disease models. The genes predisposing tumor cell lines to H2O2-mediated demise are less deciphered, however. To this end, we performed in-house transcriptional profiling of 35 cell lines and simultaneously investigated each cell line's H2O2 inhibitory concentration (IC25) based on metabolic activity. More than 100-fold differences were observed between the most resistant and sensitive cell lines. Correlation and gene ontology pathway analysis identified a rigid association with genes intertwined in cell cycle progression and proliferation, as such functional categories dominated the top ten significant processes. The ten most substantially correlating genes (Spearman r > 0.70 or < -0.70) were validated using qPCR, showing complete congruency with microarray analysis findings. Western blotting confirmed the correlation of cell cycle-related proteins negatively correlating with H2O2 IC25. Top genes related to ROS production or antioxidant defense were only modest in correlation (Spearman r > 0.40 or < -0.40). In conclusion, our in-house transcriptomic correlation analysis revealed a set of cell cycle-associated genes associated with a priori resistance or sensitivity to H2O2-induced cellular demise with the detailed and causative roles of individual genes remaining unclear.

Insight into redox regulation of apoptosis in cancer cells with multiparametric live-cell microscopy

Cellular redox status and the level of reactive oxygen species (ROS) are important regulators of apoptotic potential, playing a crucial role in the growth of cancer cell and their resistance to apoptosis. However, the relationships between the redox status and ROS production during apoptosis remain poorly explored. In this study, we present an investigation on the correlations between the production of ROS, the redox ratio FAD/NAD(P)H, the proportions of the reduced nicotinamide cofactors NADH and NADPH, and caspase-3 activity in cancer cells at the level of individual cells. Two-photon excitation fluorescence lifetime imaging microscopy (FLIM) was applied to monitor simultaneously apoptosis using the genetically encoded sensor of caspase-3, mKate2-DEVD-iRFP, and the autofluorescence of redox cofactors in colorectal cancer cells upon stimulation of apoptosis with staurosporine, cisplatin or hydrogen peroxide. We found that, irrespective of the apoptotic stimulus used, ROS accumulation correlated well with both the elevated pool of mitochondrial, enzyme-bound NADH and caspase-3 activation. Meanwhile, a shift in the contribution of bound NADH could develop independently of the apoptosis, and this was observed in the case of cisplatin. An increase in the proportion of bound NADPH was detected only in staurosporine-treated cells, this likely being associated with a high level of ROS production and their resulting detoxification. The results of the study favor the discovery of new therapeutic strategies based on manipulation of the cellular redox balance, which could help improve the anti-tumor activity of drugs and overcome apoptotic resistance.

NADPH Oxidase 4 (NOX4) in Cancer: Linking Redox Signals to Oncogenic Metabolic Adaptation

Cancer cells can survive and maintain their high proliferation rate in spite of their hypoxic environment by deploying a variety of adaptative mechanisms, one of them being the reorientation of cellular metabolism. A key aspect of this metabolic rewiring is the promotion of the synthesis of antioxidant molecules in order to counter-balance the hypoxia-related elevation of reactive oxygen species (ROS) production and thus combat the onset of cellular oxidative stress. However, opposite to their negative role in the inception of oxidative stress, ROS are also key modulatory components of physiological cellular metabolism. One of the major physiological cellular ROS sources is the NADPH oxidase enzymes (NOX-es). Indeed, NOX-es produce ROS in a tightly regulated manner and control a variety of cellular processes. By contrast, pathologically elevated and unbridled NOX-derived ROS production is linked to diverse cancerogenic processes. In this respect, NOX4, one of the members of the NOX family enzymes, is of particular interest. In fact, NOX4 is closely linked to hypoxia-related signaling and is a regulator of diverse metabolic processes. Furthermore, NOX4 expression and function are altered in a variety of malignancies. The aim of this review is to provide a synopsis of our current knowledge concerning NOX4-related processes in the oncogenic metabolic adaptation of cancer cells.

Redox-Related Proteins in Melanoma Progression

Melanoma is the most aggressive type of skin cancer. Despite the available therapies, the minimum residual disease is still refractory. Reactive oxygen and nitrogen species (ROS and RNS) play a dual role in melanoma, where redox imbalance is involved from initiation to metastasis and resistance. Redox proteins modulate the disease by controlling ROS/RNS levels in immune response, proliferation, invasion, and relapse. Chemotherapeutics such as BRAF and MEK inhibitors promote oxidative stress, but high ROS/RNS amounts with a robust antioxidant system allow cells to be adaptive and cooperate to non-toxic levels. These proteins could act as biomarkers and possible targets. By understanding the complex mechanisms involved in adaptation and searching for new targets to make cells more susceptible to treatment, the disease might be overcome. Therefore, exploring the role of redox-sensitive proteins and the modulation of redox homeostasis may provide clues to new therapies. This study analyzes information obtained from a public cohort of melanoma patients about the expression of redox-generating and detoxifying proteins in melanoma during the disease stages, genetic alterations, and overall patient survival status. According to our analysis, 66% of the isoforms presented differential expression on melanoma progression: NOS2, SOD1, NOX4, PRX3, PXDN and GPX1 are increased during melanoma progression, while CAT, GPX3, TXNIP, and PRX2 are decreased. Besides, the stage of the disease could influence the result as well. The levels of PRX1, PRX5 and PRX6 can be increased or decreased depending on the stage. We showed that all analyzed isoforms presented some genetic alteration on the gene, most of them (78%) for increased mRNA expression. Interestingly, 34% of all melanoma patients showed genetic alterations on TRX1, most for decreased mRNA expression. Additionally, 15% of the isoforms showed a significant reduction in overall patient survival status for an altered group (PRX3, PRX5, TR2, and GR) and the unaltered group (NOX4). Although no such specific antioxidant therapy is approved for melanoma yet, inhibitors or mimetics of these redox-sensitive proteins have achieved very promising results. We foresee that forthcoming investigations on the modulation of these proteins will bring significant advances for cancer therapy.

The expression and survival significance of sodium glucose transporters in pancreatic cancer

Background

Sodium glucose transporters (SGLTs) play vital roles in glucose uptake in many solid cancers, including pancreatic cancer (PC). However, their expression profile in pancreatic cancer and correlation with prognosis are not clear. Thus, we aimed to analyse the expression profile and prognostic significance of SGLT-1 and SGLT-2 in PC.

Methods

Eighty-eight patients with pancreatic ductal adenocarcinoma (PDAC) undergoing surgery in Huashan Hospital, Fudan University, from July 2017 to June 2020 were enrolled in the study. Specimens for immunohistochemistry were obtained through surgical resection. Bioinformatics analysis was performed based on the Gene Expression Omnibus (GEO), Oncomine and The Cancer Genome Atlas (TCGA) databases. The statistics were calculated using IBM SPSS Statistics, version 20 and R 4.1.1. P values lower than 0.05 were considered to indicate statistical significance.

Results

SGLT-1 but not SGLT-2 was significantly overexpressed in PDAC. Survival analysis showed that the median overall survival (OS) and progression-free survival (PFS) of patients with high SGLT-1 expression were significantly longer than that of patients with low SGLT-1 expression. Cox regression indicated that high SGLT-1 expression was an independent predictor for a better prognosis, while residual tumour status (R1 and R2) was an independent risk factor for a poor prognosis. Finally, PDZK1-interacting protein 1 (PDZK1IP1), a protein participating in the generation of reactive oxygen species, was overexpressed in PDAC and its expression was significantly correlated with SGLT-1.

Conclusions

SGLT-1 but not SGLT-2 was overexpressed in PDAC, and the overexpression of SGLT-1 could be a predictor of a better prognosis. Residual tumour status (R1 and R2) was a risk factor for poor prognosis and disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09060-4.

Common cancer treatments targeting DNA double strand breaks affect long-term memory and relate to immediate early gene expression in a sex-dependent manner

DNA double strand breaks (DSBs) have been highly studied in the context of cancers, as DSBs can lead to apoptosis or tumorigenesis. Several pharmaceuticals are widely used to target DSBs during cancer therapy. Amifostine (WR-2721) and etoposide are two commonly used drugs: amifostine reduces DSBs, whereas etoposide increases DSBs. Recently, a novel role for DSBs in immediate early gene expression, learning, and memory has been suggested. Neither amifostine nor etoposide have been assessed for their effects on learning and memory without confounding factors. Moreover, sex-dependent effects of these drugs have not been reported. We administered amifostine or etoposide to 3-4-month-old male and female C57Bl/6J mice before or after training in fear conditioning and assessed learning, memory, and immediate early genes. We observed sex-dependent baseline and drug-induced differences, with females expressing higher cFos and FosB levels than males. These were affected by both amifostine and etoposide. Post-training injections of amifostine affected long-term contextual fear memory; etoposide affected contextual and cued fear memory. These data support the hypothesis that DSBs contribute to learning and memory, and that these could play a part in cognitive side effects during common treatment regimens. The sex-dependent effects also highlight an important factor when considering treatment plans.

Association of Oxidative Stress with Neurological Disorders

BACKGORUND

Oxidative stress is one of the main contributing factors involved in cerebral biochemical impairment. The higher susceptibility of the central nervous system to reactive oxygen species mediated damage could be attributed to several factors. For example, neurons use a greater quantity of oxygen, many parts of the brain have higher concentraton of iron, and neuronal mitochondria produce huge content of hydrogen peroxide. In addition, neuronal membranes have polyunsaturated fatty acids, which are predominantly vulnerable to oxidative stress (OS). OS is the imbalance between reactive oxygen species generation and cellular antioxidant potential. This may lead to various pathological conditions and diseases, especially neurodegenerative diseases such as, Parkinson's, Alzheimer's, and Huntington's diseases.

OBJECTIVES

In this study, we explored the involvement of OS in neurodegenerative diseases.

METHODS

We used different search terms like "oxidative stress and neurological disorders" "free radicals and neurodegenerative disorders" "oxidative stress, free radicals, and neurological disorders" and "association of oxidative stress with the name of disorders taken from the list of neurological disorders. We tried to summarize the source, biological effects, and physiologic functions of ROS.

RESULTS

Finally, it was noted that more than 190 neurological disorders are associated with oxidative stress.

CONCLUSION

More elaborated studies in the future will certainly help in understanding the exact mechanism involved in neurological diseases and provide insight into revelation of therapeutic targets.

Capsaicin inhibits cell proliferation by enhancing oxidative stress and apoptosis through SIRT1/NOX4 signaling pathways in HepG2 and HL-7702 cells

Capsaicin could suppress the proliferation of cancer cells and inhibit many biochemical pathways associated with tumorigenesis and metastasis. This study investigates the effects of capsaicin in both hepatocellular carcinoma (HepG2) and normal hepatocytes (HL-7702) via the SIRT1/NOX4 signaling pathway. After determination of cytotoxic concentrations of capsaicin on HL-7702 and HepG2 cells, we measured total oxidant status (TOS), reduced glutathione (GSH), 8-hydroxydeoxyguanosine (8-OHdG), cytochrome c (CYC), caspase3 (CASP3), Bcl-2, Bax, sirtuin1 (SIRT1), and NADPH oxidases4 (NOX4) levels. Besides this, we analyzed the messenger RNA and protein levels of SIRT1 and NOX4. We found that capsaicin increased TOS, 8-OHdG, CASP3, CYC, Bax, and NOX4 levels, and decreased Bcl-2, GSH, and SIRT1 in a concentration-dependent manner in HepG2 cells. However, especially low capsaicin concentration (128.75 µM) enhanced GSH and SIRT levels and reduced TOS, CASP3, CYC, 8-OHdG, and NOX4 levels in HL-7702 cells (p < 0.05). Interestingly, 128.75 and 172.8 µM capsaicin treatment increased SIRT1 expression levels in HL-7702 cells, resulting in an increase in GSH levels and a decrease in TOS, CYC, CAPS3, and 8-OHdG levels through NOX4 inhibition. Furthermore, we demonstrated a significant decrease in SIRT1 protein levels and an increase in NOX4 protein levels and caspase-3/-7 activities in both HL-7702 and HepG2 cells treated with 261.5 µM capsaicin. Additionally, morphological changes in HL-7702 and HepG2 cells treated with capsaicin correlated with the enhancement in oxidative burden, DNA damage, and apoptosis. Our results show that capsaicin effectively might cause higher oxidative, apoptotic, and DNA damage in HepG2 cells than in HL-7702 cells through the SIRT1/NOX4 signaling pathway.

Effects of Iodonium Analogs on Nadph Oxidase 1 in Human Colon Cancer Cells

Recent studies suggest that of the molecules postulated to function as inhibitors of the NADPH oxidase family of enzymes iodonium analogs known to broadly interfere with flavin dehydrogenase function demonstrate mechanistic validity as NADPH oxidase poisons. In recent work, we have produced a series of novel iodonium compounds as putative inhibitors of these oxidases. To evaluate the potential utility of two novel molecules with favorable chemical properties, NSC 740104 and NSC 751140, we compared effects of these compounds to the two standard inhibitors of this class, diphenyleneiodonium and di-2-thienyliodonium, with respect to antiproliferative, cell cycle, and gene expression effects in human colon cancer cells that require the function of NADPH oxidase 1. Both new agents blocked NADPH oxidase-related reactive oxygen production, inhibited tumor cell proliferation, produced a G1/S block in cell cycle progression, and inhibited NADPH oxidase 1 expression at the mRNA and protein levels at low nM concentrations in a fashion similar to or better than the parent molecules. These studies suggest that NSC 740104 and NSC 751140 should be developed further as mechanistic tools to better understand the role of NADPH oxidase inhibition as an approach to the development of novel therapeutic agents for colon cancer.

Redox Regulation and Oxidative Stress in Mammalian Oocytes and Embryos Developed In Vivo and In Vitro

Oocytes and preimplantation embryos require careful regulation of the redox environment for optimal development both in vivo and in vitro. Reactive oxygen species (ROS) are generated throughout development as a result of cellular metabolism and enzyme reactions. ROS production can result in (i) oxidative eustress, where ROS are helpful signalling molecules with beneficial physiological functions and where the redox state of the cell is maintained within homeostatic range by a closely coupled system of antioxidants and antioxidant enzymes, or (ii) oxidative distress, where excess ROS are deleterious and impair normal cellular function. in vitro culture of embryos exacerbates ROS production due to a range of issues including culture-medium composition and laboratory culture conditions. This increase in ROS can be detrimental not only to assisted reproductive success rates but can also result in epigenetic and genetic changes in the embryo, resulting in transgenerational effects. This review examines the effects of oxidative stress in the oocyte and preimplantation embryo in both the in vivo and in vitro environment, identifies mechanisms responsible for oxidative stress in the oocyte/embryo in culture and approaches to reduce these problems, and briefly examines the potential impacts on future generations.

Rac-dependent feedforward autoactivation of NOX2 leads to oxidative burst

NADPH oxidase 2 (NOX2) produces the superoxide anion radical (O₂⁻), which has functions in both cell signaling and immune defense. NOX2 is a multimeric-protein complex consisting of several protein subunits including the GTPase Rac. NOX2 uniquely facilitates an oxidative burst, which is described by initially slow O₂⁻ production, which increases over time. The NOX2 oxidative burst is considered critical to immune defense because it enables expedited O₂⁻ production in response to infections. However, the mechanism of the initiation and progression of this oxidative burst and its implications for regulation of NOX2 have not been clarified. In this study, we show that the NOX2 oxidative burst is a result of autoactivation of NOX2 coupled with the redox function of Rac. NOX2 autoactivation begins when active Rac triggers NOX2 activation and the subsequent production of O₂⁻, which in turn activates redox-sensitive Rac. This activated Rac further activates NOX2, amplifying the feedforward cycle and resulting in a NOX2-mediated oxidative burst. Using mutagenesis-based kinetic and cell analyses, we show that enzymatic activation of Rac is exclusively responsible for production of the active Rac trigger that initiates NOX2 autoactivation, whereas redox-mediated Rac activation is the main driving force of NOX2 autoactivation and contributes to generation of ∼98% of the active NOX2 in cells. The results of this study provide insight into the regulation of NOX2 function, which could be used to develop therapeutics to control immune responses associated with dysregulated NOX2 oxidative bursts.

Oxidative Stress Links Aging-Associated Cardiovascular Diseases and Prostatic Diseases

The incidence of chronic aging-associated diseases, especially cardiovascular and prostatic diseases, is increasing with the aging of society. Evidence indicates that cardiovascular diseases usually coexist with prostatic diseases or increase its risk, while the pathological mechanisms of these diseases are unknown. Oxidative stress plays an important role in the development of both cardiovascular and prostatic diseases. The levels of oxidative stress biomarkers are higher in patients with cardiovascular diseases, and these also contribute to the development of prostatic diseases, suggesting cardiovascular diseases may increase the risk of prostatic diseases via oxidative stress. This review summarizes the role of oxidative stress in cardiovascular and prostatic diseases and also focuses on the main shared pathways underlying these diseases, in order to provide potential prevention and treatment targets.

Chidamide-Induced Accumulation of Reactive Oxygen Species Increases Lenalidomide Sensitivity Against Multiple Myeloma Cells

Background

Lenalidomide, an immunomodulatory drug (IMiD), is an effective therapy for the treatment of multiple myeloma (MM). However, prolonged treatment may be accompanied by toxicity, second primary malignancies, and drug resistance. There is an inherent vulnerability in MM cells that high rates of immunoglobulin synthesis resulting in the high level of reactive oxygen species (ROS). This provides a therapeutic potential for MM.

Materials and Methods

The intracellular ROS levels, H₂O₂ production and glutathione (GSH) levels were measured using detection kit. Cell viability was evaluated using cell-counting kit-8 (CCK-8) and soft agar colony formation assay. Apoptosis was determined in whole living cells using flow cytometry. Chidamide and its anti-myeloma efficacy in combination with lenalidomide were characterized in MM cell lines in vitro and in a mouse xenograft model. Moreover, Western blotting, immunofluorescence and immunohistochemical studies were performed.

Results

ROS levels increased in a time- and dose-dependent manner with chidamide treatment. Moreover, the GSH levels were decreased and the mRNA level of SLC7A11 downregulated after chidamide treatment. The co-treatment with chidamide and lenalidomide increased apoptosis and proliferation inhibition, with combination index (CI) in the synergistic range (0.2–0.5) using the Chou–Talalay method. The cooperative anti-myeloma efficacy was confirmed in the murine model, and immunohistochemical studies also supported this potentiation. Chidamide enhanced the effect of lenalidomide-induced degradation of IKZF1 and IKZF3 by elevating H₂O₂. In addition, co-treatment with chidamide and lenalidomide increased biomarkers of caspase and DNA damage.

Conclusion

Elevated ROS production may constitute a potential biochemical basis for anti-myeloma effects of chidamide plus lenalidomide. The results of this study confirm the synergistic effect of chidamide and lenalidomide against MM and provide a promising therapeutic strategy for MM.

Transforming Growth Factor-β and Oxidative Stress in Cancer: A Crosstalk in Driving Tumor Transformation

Simple Summary

Metabolic changes in tumor microenvironment play a critical role in cancer, related to the accumulated alterations in signaling pathways that control cellular metabolism. Cancer metabolic deregulation is related to specific events such as the control of oxidative stress, and in particular the redox imbalance with aberrant oxidant production and/or a deregulation of the efficacy of the antioxidant systems. In cancer cells, different cytokines are involved in the development and/or progression of cancer; among these cytokines, the transforming growth factor β (TGF-β) is central to tumorigenesis and cancer progression. In tumor cells, it has been demonstrated that there is a close correlation between oxidative stress and TGF-β; this crosstalk strongly contributes to tumorigenesis, both in tumor development and in mediating its invasiveness. This review is addressed to better understanding this crosstalk between TGF-β and oxidative stress in cancer cell metabolism, in an attempt to improve the pharmacological and therapeutic approach against cancer.

Abstract

Cancer metabolism involves different changes at a cellular level, and altered metabolic pathways have been demonstrated to be heavily involved in tumorigenesis and invasiveness. A crucial role for oxidative stress in cancer initiation and progression has been demonstrated; redox imbalance, due to aberrant reactive oxygen species (ROS) production or deregulated efficacy of antioxidant systems (superoxide dismutase, catalase, GSH), contributes to tumor initiation and progression of several types of cancer. ROS may modulate cancer cell metabolism by acting as secondary messengers in the signaling pathways (NF-kB, HIF-1α) involved in cellular proliferation and metastasis. It is known that ROS mediate many of the effects of transforming growth factor β (TGF-β), a key cytokine central in tumorigenesis and cancer progression, which in turn can modulate ROS production and the related antioxidant system activity. Thus, ROS synergize with TGF-β in cancer cell metabolism by increasing the redox imbalance in cancer cells and by inducing the epithelial mesenchymal transition (EMT), a crucial event associated with tumor invasiveness and metastases. Taken as a whole, this review is addressed to better understanding this crosstalk between TGF-β and oxidative stress in cancer cell metabolism, in the attempt to improve the pharmacological and therapeutic approach against cancer.

A Ferroptosis-Related lncRNAs Signature Predicts Prognosis and Immune Microenvironment for Breast Cancer

Background: Ferroptosis, a regulated cell death which is driven by the iron-dependent peroxidation of lipids, plays an important role in cancer. However, studies about ferroptosis-related Long non-coding RNAs (lncRNAs) in breast cancer (BC) are limited. Besides, the prognostic role of ferroptosis-related lncRNAs and their relationship to immune microenvironment in breast cancer remain unclear. This study aimed to explore the potential prognostic value of ferroptosis-related lncRNAs and their relationship to immune microenvironment in breast cancer.

Methods: RNA-sequencing data of female breast cancer patients were downloaded from TCGA database. 937 patients were randomly separated into training or validation cohort in 2:1 ratio. Ferroptosis-related lncRNAs were screened by Pearson correlation analysis with 239 reported ferroptosis-related genes. A ferroptosis-related lncRNAs signature was constructed with univariate and multivariate Cox regression analyses in the training cohort, and its prognostic value was further tested in the validation cohort.

Results: An 8-ferroptosis-related-lncRNAs signature was developed by multivariate Cox regression analysis to divide patients into two risk groups. Patients in the high-risk group had worse prognosis than patients in the low-risk group. Multivariate Cox regression analysis showed the risk score was an independent prognostic indicator. Receiver operating characteristic curve (ROC) analysis proved the predictive accuracy of the signature. The area under time-dependent ROC curve (AUC) reached 0.853 at 1 year, 0.802 at 2 years, 0.740 at 5 years in the training cohort and 0.791 at 1 year, 0.778 at 2 years, 0.722 at 5 years in the validation cohort. Further analysis demonstrated that immune-related pathways were significantly enriched in the high-risk group. Analysis of the immune cell infiltration landscape showed that breast cancer in the high-risk group tended be immunologically “cold”.

Conclusion: We identified a novel ferroptosis-related lncRNA signature which could precisely predict the prognosis of breast cancer patients. Ferroptosis-related lncRNAs may have a potential role in the process of anti-tumor immunity and serve as therapeutic targets for breast cancer.

Sulforaphane Impact on Reactive Oxygen Species (ROS) in Bladder Carcinoma

Sulforaphane (SFN) is a natural glucosinolate found in cruciferous vegetables that acts as a chemopreventive agent, but its mechanism of action is not clear. Due to antioxidative mechanisms being thought central in preventing cancer progression, SFN could play a role in oxidative processes. Since redox imbalance with increased levels of reactive oxygen species (ROS) is involved in the initiation and progression of bladder cancer, this mechanism might be involved when chemoresistance occurs. This review summarizes current understanding regarding the influence of SFN on ROS and ROS-related pathways and appraises a possible role of SFN in bladder cancer treatment.