Increased Nox1 and hydrogen peroxide in prostate cancer

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.

Fluoride-Induced Mitochondrial Dysfunction and Approaches for Its Intervention

Fluoride is present everywhere in nature. The primary way that individuals are exposed to fluoride is by drinking water. It's interesting to note that while low fluoride levels are good for bone and tooth growth, prolonged fluoride exposure is bad for human health. Additionally, preclinical studies link oxidative stress, inflammation, and programmed cell death to fluoride toxicity. Moreover, mitochondria play a crucial role in the production of reactive oxygen species (ROS). On the other hand, little is known about fluoride's impact on mitophagy, biogenesis, and mitochondrial dynamics. These actions control the growth, composition, and organisation of mitochondria, and the purification of mitochondrial DNA helps to inhibit the production of reactive oxygen species and the release of cytochrome c, which enables cells to survive the effects of fluoride poisoning. In this review, we discuss the different pathways involved in mitochondrial toxicity and dysfunction induced by fluoride. For therapeutic approaches, we discussed different phytochemical and pharmacological agents which reduce the toxicity of fluoride via maintained by imbalanced cellular processes, mitochondrial dynamics, and scavenging the ROS.

Anticancer effect of superoxide dismutase on canine mammary gland tumour in vitro

BACKGROUND

Reactive oxygen species (ROS) have been shown to promote tumour growth and metastasis in human cell lines. The superoxide anion (•O2 - ) is produced during ROS formation and is involved in tumour cell signalling.

OBJECTIVES

Superoxide dismutase (SOD) has been applied to canine mammary gland tumours to investigate its antitumour effects in vitro.

METHODS

Cell proliferation, cell cycle cell migration assays, reverse transcription-quantitative polymerase chain reaction, and western blot analysis were performed to determine the effects of SOD on canine mammary tumour cell line.

RESULTS

SOD treatment resulted in anti-proliferative effects and mediated cell cycle arrest in the canine mammary gland tumour cell lines (CIPp and CIPm). It also downregulated the expression of N-cadherin and Vimentin.

CONCLUSIONS

The results confirmed that SOD inhibits tumour cell proliferation and migration, thus supporting the potential applications of SOD as a chemotherapeutic agent for canine mammary gland tumours.

Anti-oxidant potential of plants and probiotic spp. in alleviating oxidative stress induced by H2O2

Cells produce reactive oxygen species (ROS) as a metabolic by-product. ROS molecules trigger oxidative stress as a feedback response that significantly initiates biological processes such as autophagy, apoptosis, and necrosis. Furthermore, extensive research has revealed that hydrogen peroxide (H2O2) is an important ROS entity and plays a crucial role in several physiological processes, including cell differentiation, cell signalling, and apoptosis. However, excessive production of H2O2 has been shown to disrupt biomolecules and cell organelles, leading to an inflammatory response and contributing to the development of health complications such as collagen deposition, aging, liver fibrosis, sepsis, ulcerative colitis, etc. Extracts of different plant species, phytochemicals, and Lactobacillus sp (probiotic) have been reported for their anti-oxidant potential. In this view, the researchers have gained significant interest in exploring the potential plants spp., their phytochemicals, and the potential of Lactobacillus sp. strains that exhibit anti-oxidant properties and health benefits. Thus, the current review focuses on comprehending the information related to the formation of H2O2, the factors influencing it, and their pathophysiology imposed on human health. Moreover, this review also discussed the anti-oxidant potential and role of different extract of plants, Lactobacillus sp. and their fermented products in curbing H2O2‑induced oxidative stress in both in-vitro and in-vivo models via boosting the anti-oxidative activity, inhibiting of important enzyme release and downregulation of cytochrome c, cleaved caspases-3, - 8, and - 9 expression. In particular, this knowledge will assist R&D sections in biopharmaceutical and food industries in developing herbal medicine and probiotics-based or derived food products that can effectively alleviate oxidative stress issues induced by H2O2 generation.

The generation of 5-N-glycolylneuraminic acid as a consequence of high levels of reactive oxygen species

The presence of N-glycolylneuraminic acid (Neu5Gc), a non-human sialic acid in cancer patients, is currently attributed to the consumption of red meat. Excess dietary red meat has been considered a risk factor causing chronic inflammation and for the development of cancers. However, it remains unknown whether Neu5Gc can be generated via a chemical reaction rather than via a metabolic pathway in the presence of high levels of reactive oxygen species (ROS) found in the inflammatory and tumor environments. In this study, the conversion of N-acetylneuraminic acid (Neu5Ac) to Neu5Gc has been assessed in vitro under conditions mimicking the hydroxyl radical-rich humoral environment found in inflammatory and cancerous tissues. As a result, Neu5Gc has been detected via liquid chromatography-multiple reaction monitoring mass spectrometry. Furthermore, this conversion has also been found to take place in serum biomatrix containing ROS and in cancer cell cultures with induced ROS production.

Engineering the MoS2 /MXene Heterostructure for Precise and Noninvasive Diagnosis of Prostate Cancer with Clinical Specimens

High-throughput metabolic fingerprinting has been deemed one of the most promising strategies for addressing the high false positive rate of prostate cancer (PCa) diagnosis in the prostate-specific antigen (PSA) gray zone. However, the current metabolic fingerprinting remains challenging in achieving high-precision metabolite detection in complex biological samples (e.g., serum and urine). Herein, a novel self-assembly MoS₂ /MXene heterostructure nanocomposite with a tailored doping ratio of 10% is presented as a matrix for laser desorption ionization mass spectrometry analysis in clinical biosamples. Notably, owing to the two-dimensional architecture and doping effect, MoS₂ /MXene demonstrates favorable laser desorption ionization performance with low adsorption energy, which is evidenced by efficient urinary metabolic fingerprinting with an enhanced area under curve (AUC) diagnosis capability of 0.959 relative to that of serum metabolic fingerprinting (AUC = 0.902) for the diagnosis of PCa in the PSA gray zone. Thus, this MoS₂ /MXene heterostructure is anticipated to offer a novel strategy to precisely and noninvasively diagnose PCa in the PSA gray zone.

Psoralidin inhibits osteosarcoma growth and metastasis by downregulating ITGB1 expression via the FAK and PI3K/Akt signaling pathways

BACKGROUND

Psoralea corylifolia is a medicinal leguminous plant that has long been used to treat various diseases. Psoralidin (PSO) is the main extract compound of P. corylifolia and exhibits antibacterial, antitumor, anti-inflammatory, antioxidant, and other pharmacological activities. PSO has demonstrated inhibitory effects in several cancers; however, its inhibitory effect on osteosarcoma has not been reported. This study aimed to evaluate the inhibitory effect of PSO on osteosarcoma and elucidate the underlying molecular mechanisms.

METHODS

Crystal violet, cell counting kit-8 (CCK8), and 5-Ethynyl-2'-deoxyuridine (EdU) staining assays were used to assess the inhibitory effect of PSO on the proliferation of 143B and MG63 osteosarcoma cells. Wound healing and Transwell assays were conducted to evaluate the effects of PSO on osteosarcoma cell migration and invasion. The cell cycle and apoptosis were analyzed using flow cytometry. To determine the possible molecular mechanisms, RNA-sequencing was performed and protein expression was analyzed by western blotting. The inhibitory effect of PSO on osteosarcoma in vivo was analyzed using a mouse model of orthotopic osteosarcoma and immunohistochemistry.

RESULTS

PSO inhibited osteosarcoma cell proliferation in a concentration-dependent manner, inhibited cell migration and invasion, and induced cell-cycle arrest and apoptosis. Mechanistically, PSO treatment significantly inhibited the focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways by downregulating ITGB1 expression in both MG63 and 143B cells. Furthermore, we demonstrated that PSO restrained osteosarcoma growth in vivo.

CONCLUSION

PSO may suppress osteosarcoma via the FAK and PI3K/Akt signaling pathways by downregulating ITGB1 expression.

The role of hypoxia on prostate cancer progression and metastasis

Prostate cancer is the second most common cancer diagnosed in men and the fifth-leading cause of cancer death in men worldwide. Like any solid tumor, the hypoxic microenvironment of prostatic cancer drives hypoxia-inducible factors (HIFs) to mediate cell adaptions to hypoxic conditions. HIFs direct different signaling pathways such as PI3K/Akt/mTOR, NOX, and Wnt/β-Catenin to tumor progression depending on the degree of hypoxia. HIFs regulate cytoskeleton protein expression, promoting epithelial-mesenchymal transition (EMT), which occurs when cancer cells lose cell-to-cell adhesions and start invasion and metastasis. Through activating pathways, the hypoxic microenvironment maintains the self-renewal, potency, and anti-apoptotic function of prostate cancer cells and induces tumor metastasis and transformation. These pathways could serve as a potential target for prostate cancer therapy. HIFs increase the expression of androgen receptors on cancer cells maintaining the growth and survival of prostate cancer and the development of its castration resistance. In this review, we elaborate on the role of hypoxia in prostatic cancer pathogenesis and different hypoxia-induced mechanisms.

Photodynamic therapy: Innovative approaches for antibacterial and anticancer treatments

Photodynamic therapy is an alternative treatment mainly for cancer but also for bacterial infections. This treatment dates back to 1900 when a German medical school graduate Oscar Raab found a photodynamic effect while doing research for his doctoral dissertation with Professor Hermann von Tappeiner. Unexpectedly, Raab revealed that the toxicity of acridine on paramecium depends on the intensity of light in his laboratory. Photodynamic therapy is therefore based on the administration of a photosensitizer with subsequent light irradiation within the absorption maxima of this substance followed by reactive oxygen species formation and finally cell death. Although this treatment is not a novelty, there is an endeavor for various modifications to the therapy. For example, selectivity and efficiency of the photosensitizer, as well as irradiation with various types of light sources are still being modified to improve final results of the photodynamic therapy. The main aim of this review is to summarize anticancer and antibacterial modifications, namely various compounds, approaches, and techniques, to enhance the effectiveness of photodynamic therapy.

A Mitochondrion-Targeting Protein (B2) Primes ROS/Nrf2-Mediated Stress Signals, Triggering Apoptosis and Necroptosis in Lung Cancer

The betanodavirus B2 protein targets mitochondria and triggers mitochondrion-mediated cell death signaling in lung cancer cells; however, its molecular mechanism remains unknown. In this study, we observed that B2 triggers hydrogen peroxide/Nrf2-involved stress signals in the dynamic regulation of non-small lung cancer cell (NSCLC)-programmed cell death. Here, the B2 protein works as a necrotic inducer that triggers lung cancer death via p53 upregulation and RIP3 expression, suggesting a new perspective on lung cancer therapy. We employed the B2 protein to target A549 lung cancer cells and solid tumors in NOD/SCID mice. Tumors were collected and processed for the hematoxylin and eosin staining of tissue and cell sections, and their sera were used for blood biochemistry analysis. We observed that B2 killed an A549 cell-induced solid tumor in NOD/SCID mice; however, the mutant ΔB2 did not. In NOD/SCID mice, B2 (but not ΔB2) induced both p53/Bax-mediated apoptosis and RIPK3-mediated necroptosis. Finally, immunochemistry analysis showed hydrogen peroxide /p38/Nrf2 stress strongly inhibited the production of tumor markers CD133, Thy1, and napsin, which correlate with migration and invasion in cancer cells. This B2-triggered, ROS/Nrf2-mediated stress signal triggered multiple signals via pathways that killed A549 lung cancer tumor cells in vivo. Our results provide novel insight into lung cancer management and drug therapy.

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.

Exosomes from prostate cancer cell lines: Isolation optimisation and characterisation

Exosomes are considered to be a rich source of biomarkers, hence in this article we examine the best procedure for their isolation. We examine several isolation procedures, exosome storage conditions and other conditions affecting exosome production by prostate cell lines. We selected four different commercially available kits based on different principles to achieve exosome isolation, the best being magnetic-based. In addition, we found storage at - 20 °C to be good for storing isolated exosomes and that exosomes were produced from the cancerous prostate cell line 22Rv1 in much greater amounts than the non-cancerous prostate cell line RWPE1. We also found differences in the response of both cell lines in the production of exosomes as a result of stress, i.e. exposure to hydrogen peroxide and starvation. The effect of Triton X-100 on exosome lysis was examined using two different surfactant concentrations by analysis of the exosome count and change in the exosome size. The final part of the article details the advantages of the use of a 2D biochip prepared in-house over a commercially available 3D biochip for monitoring the interaction of exosomes via its surface receptors (CD63) with an immobilised ligand (anti-CD63 antibodies) using surface plasmon resonance. The final experiment shows the potential of lectin fluorescent microarrays for the analysis of glycans present in lysed exosomes.

Characterization of Immune-Based Molecular Subtypes and Prognostic Model in Prostate Adenocarcinoma

Prostate adenocarcinoma (PRAD), also named prostate cancer, the most common visceral malignancy, is diagnosed in male individuals. Herein, in order to obtain immune-based subtypes, we performed an integrative analysis to characterize molecular subtypes based on immune-related genes, and further discuss the potential features and differences between identified subtypes. Simultaneously, we also construct an immune-based risk model to assess cancer prognosis. Our findings showed that the two subtypes, C1 and C2, could be characterized, and the two subtypes showed different characteristics that could clearly describe the heterogeneity of immune microenvironments. The C2 subtype presented a better survival rate than that in the C1 subtype. Further, we constructed an immune-based prognostic model based on four screened abnormally expressed genes, and they were selected as predictors of the robust prognostic model (AUC = 0.968). Our studies provide reference for characterization of molecular subtypes and immunotherapeutic agents against prostate cancer, and the developed robust and useful immune-based prognostic model can contribute to cancer prognosis and provide reference for the individualized treatment plan and health resource utilization. These findings further promote the development and application of precision medicine in prostate cancer.

Pathological Roles of Reactive Oxygen Species in Male Reproduction

Reactive oxygen species (ROS) are free radicals that have at least one unpaired electron and play specific roles in the human body. An imbalance of ROS and antioxidant levels gives rise to a condition called oxidative stress. High levels of ROS in the male reproductive tract can interfere with its normal functioning and can even pose as toxic to the sperm, inhibiting sperm functioning (including motility) and metabolism. Oxidative stress resulting from ROS and lipid peroxidation is one of the major causes of male infertility including infertility in varicocele patients. These may cause DNA and peroxidative damage and apoptosis. Production of ROS in excess also leads to erectile dysfunction (ED). In recent years, studies have also linked oxidative stress with the development, progress, and therapy response of prostate cancer patients. The present study summarizes the pathological roles of ROS in male reproductive problems such as infertility, ED, and prostate cancer and also provide an insight into the probable mechanism through which ROS exert their pathological impact.

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.

Psoralidin, a natural compound from Psoralea corylifolia, induces oxidative damage mediated apoptosis in colon cancer cells

Psoralidin (PSO) is a natural coumarin isolated from the seeds of Psoralea corylifolia Linn. Previous studies have reported that PSO exerts numerous pharmacological bioactivities including antitumor. The present study aimed to investigate its anticancer effect using colon cancer cells. Cultured HT-29 and HCT-116 colon cancer cells were treated with different concentrations of PSO, and the cell viability, the intracellular reactive oxygen species (ROS), the protein expression, and the apoptosis were determined by MTT assay, DCFH₂ -DA fluorescence probe, Western blotting, and Annexin V/7-AAD staining, respectively. The activities of caspase 3/7 were determined by a commercial kit. Our study found that PSO effectively induces apoptotic cell death mediated by caspase 3/7 in HT-29 and HCT-116 colon cancer cells. PSO treatment rapidly boosts the ROS generation, which is responsible for the PSO-triggered DNA damage, mitochondria membrane potential decrease and caspase 3/7 activation, and c-Jun N-terminal kinase 1/2 activation. Collectively, these results showed that PSO triggered oxidative damage mediated apoptosis in colon cancer cells.

Recent Development of Prodrugs of Gemcitabine

Gemcitabine is a nucleoside analog that has been used widely as an anticancer drug for the treatment of a variety of conditions, including ovarian, bladder, non-small-cell lung, pancreatic, and breast cancer. However, enzymatic deamination, fast systemic clearance, and the emergence of chemoresistance have limited its efficacy. Different prodrug strategies have been explored in recent years, seeking to obtain better pharmacokinetic properties, efficacy, and safety. Different drug delivery strategies have also been employed, seeking to transform gemcitabine into a targeted medicine. This review will provide an overview of the recent developments in gemcitabine prodrugs and their effectiveness in treating cancerous tumors.

CYLD destabilizes NoxO1 protein by promoting ubiquitination and regulates prostate cancer progression

The NADPH oxidase (Nox) family of enzymes is solely dedicated in the generation of reactive oxygen species (ROS). ROS generated by Nox are involved in multiple signaling cascades and a myriad of pathophysiological conditions including cancer. As such, ROS seem to have both detrimental and beneficial roles in a number of cellular functions, including cell signaling, growth, apoptosis and proliferation. Regulatory mechanisms are required to control the activity of Nox enzymes in order to maintain ROS balance within the cell. Here, we performed genome-wide screening for deubiquitinating enzymes (DUBs) regulating Nox organizer 1 (NoxO1) protein expression using a CRISPR/Cas9-mediated DUB-knockout library. We identified cylindromatosis (CYLD) as a binding partner regulating NoxO1 protein expression. We demonstrated that the overexpression of CYLD promotes ubiquitination of NoxO1 protein and reduces the NoxO1 protein half-life. The destabilization of NoxO1 protein by CYLD suppressed excessive ROS generation. Additionally, CRISPR/Cas9-mediated knockout of CYLD in PC-3 cells promoted cell proliferation, migration, colony formation and invasion in vitro. In xenografted mice, injection of CYLD-depleted cells consistently led to tumor development with increased weight and volume. Taken together, these results indicate that CYLD acts as a destabilizer of NoxO1 protein and could be a potential tumor suppressor target for cancer therapeutics.

Hypocrellin B-based activatable photosensitizers for specific photodynamic effects against high H2O2-expressing cancer cells

A novel tumor-related biomarker, a H₂O₂-activatable photosensitizer 4 based on the 1,3-dicarbonyl enol moieties of hypocrellin B (3), was designed and synthesized. The photosensitizer 4 showed a blue-shifted absorption band compared with 3, and showed negligible photosensitizing ability without H₂O₂. However, the release of 3 from 4 by the reaction with H₂O₂ regenerated the photosensitizing ability. Furthermore, 4 exhibited selective and effective photo-cytotoxicity against high H₂O₂-expressing cancer cells upon photo-irradiation with 660 nm light, which is inside the phototherapeutic window.

Extraction and Nano-Sized Delivery Systems for Phlorotannins to Improve Its Bioavailability and Bioactivity

This review aims to provide an informative summary of studies on extraction and nanoencapsulation of phlorotannins to improve their bioavailability and bioactivity. The origin, structure, and different types of phlorotannins were briefly discussed, and the extraction/purification/characterization methods for phlorotannins were reviewed, with a focus on techniques to improve the bioactivities and bioavailability of phlorotannins via nano-sized delivery systems. Phlorotannins are promising natural polyphenol compounds that have displayed high bioactivities in several areas: anticancer, anti-inflammation, anti-HIV, antidiabetic, and antioxidant. This review aims to provide a useful reference for researchers working on developing better utilization strategies for phlorotannins as pharmaceuticals, therapeuticals, and functional food supplements.

Reactive oxygen species: Role in carcinogenesis, cancer cell signaling and tumor progression

Cancer is one of the major causes of death in the world and its global burden is expected to continue increasing. In several types of cancers, reactive oxygen species (ROS) have been extensively linked to carcinogenesis and cancer progression. However, studies have reported conflicting evidence regarding the role of ROS in cancer, mostly dependent on the cancer type or the step of the tumorigenic process. We review recent studies describing diverse aspects of the interplay of ROS with cancer in the different stages of cancer progression, with a special focus on their role in carcinogenesis, their importance for cancer cell signaling and their relationship to the most prevalent cancer risk factors.

Recent Advances in Hydrogen Peroxide Responsive Organoborons for Biological and Biomedical Applications

Hydrogen peroxide is the most stable reactive oxygen species generated endogenously, participating in numerous physiological processes and abnormal pathological conditions. Mounting evidence suggests that a higher level of H₂ O₂ exists in various disease conditions. Thus, H₂ O₂ functions as an ideal target for site-specific bioimaging and therapeutic targeting. The unique reactivity of organoborons with H₂ O₂ provides a method for developing chemoselective molecules for biological and biomedical applications. This review highlights the design and application of boron-derived molecules for H₂ O₂ detection, and the utility of boron moieties toward masking reactive compounds leading to the development of metal prochelators and prodrugs for selectively delivering an active species at the target sites with elevated H₂ O₂ levels. Additionally, the emergence of H₂ O₂ -responsive theranostic agents consisting of both therapeutic and diagnostic moieties in one integrated system are discussed. The purpose of this review is to provide a better understanding of the role of boron-derived molecules toward biological and pharmacological applications.

Development and Verification of a Prostate Cancer Prognostic Signature Based on an Immunogenomic Landscape Analysis

Purpose

Prostate cancer (PCa) has a high incidence among older men. Until now, there are no immunological markers available to predict PCa patients’ survival. Therefore, it is necessary to explore the immunological characteristics of PCa.

Methods

First, we retrieved RNA-seq and clinical data of 499 PCa and 52 normal prostate tissue samples from the Cancer Genome Atlas (TCGA). We identified 193 differentially expressed immune-related genes (IRGs) between PCa and normal prostate tissues. Functional enrichment analyses showed that the immune system can participate in PCa initiation. Then, we constructed a correlation network between transcription factors (TFs) and IRGs. We performed univariate and multivariate Cox regression analyses and identified five key prognostic IRGs (S100A2, NOX1, IGHV7-81, AMH, and AGTR1). Finally, a predictive nomogram was established and verified by the C-index.

Results

We successfully constructed and validated an immune-related PCa prediction model. The signature could independently predict PCa patients’ survival. Results showed that high-immune-risk patients were correlated with advanced stage. We also validated the S100A2 expression in vitro using PCa and normal prostate tissues. We found that higher S100A2 expressions were related to lower biochemical recurrences. Additionally, higher AMH expressions were related to higher Gleason score, lymph node metastasis and positive rate, and tumor stages, and higher ATGR1 expressions were related to lower PSA value.

Conclusion

Overall, we detected five IRGs (S100A2, NOX1, IGHV7-81, AMH, and AGTR1) that can be used as independent PCa prognostic factors.

Novel Prostate Cancer Biomarkers: Aetiology, Clinical Performance and Sensing Applications

The review initially provides a short introduction to prostate cancer (PCa) incidence, mortality, and diagnostics. Next, the need for novel biomarkers for PCa diagnostics is briefly discussed. The core of the review provides details about PCa aetiology, alternative biomarkers available for PCa diagnostics besides prostate specific antigen and their biosensing. In particular, low molecular mass biomolecules (ions and metabolites) and high molecular mass biomolecules (proteins, RNA, DNA, glycoproteins, enzymes) are discussed, along with clinical performance parameters.

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.

Chemodynamic therapy agents Cu(II) complexes of quinoline derivatives induced ER stress and mitochondria-mediated apoptosis in SK-OV-3 cells

Three Cu(II) complexes of quinoline derivatives as cancer chemodynamic therapy agents were synthesized and characterized. These complexes were heavily taken up by cells and reacted with cellular glutathione (GSH) to reduce Cu²⁺ to Fenton-like Cu⁺, which catalyzed endogenous H₂O₂ to produce the highly toxic hydroxyl radicals (•OH) to kill cancer cells. Cu1 and Cu2 initiated CAT activity declines, mitochondrial membrane potential and ATP concentration decrease, mitochondrial Ca²⁺ overload and ER stress response, leading to cell cycle arrest in sub-G1 and cancer cell caspase-dependent apoptosis. On account of the high GSH and H₂O₂ specific properties of the tumor microenvironment, Cu1 and Cu2 exhibited higher in vitro anticancer activity and lower toxicity to normal cells. Cu1 and Cu2 efficiently inhibited tumor growth in the SK-OV-3 xenograft mouse model without obvious systemic toxicity.

Oxidative Stress in Cancer Cell Metabolism

Reactive oxygen species (ROS) are important in regulating normal cellular processes whereas deregulated ROS leads to the development of a diseased state in humans including cancers. Several studies have been found to be marked with increased ROS production which activates pro-tumorigenic signaling, enhances cell survival and proliferation and drives DNA damage and genetic instability. However, higher ROS levels have been found to promote anti-tumorigenic signaling by initiating oxidative stress-induced tumor cell death. Tumor cells develop a mechanism where they adjust to the high ROS by expressing elevated levels of antioxidant proteins to detoxify them while maintaining pro-tumorigenic signaling and resistance to apoptosis. Therefore, ROS manipulation can be a potential target for cancer therapies as cancer cells present an altered redox balance in comparison to their normal counterparts. In this review, we aim to provide an overview of the generation and sources of ROS within tumor cells, ROS-associated signaling pathways, their regulation by antioxidant defense systems, as well as the effect of elevated ROS production in tumor progression. It will provide an insight into how pro- and anti-tumorigenic ROS signaling pathways could be manipulated during the treatment of cancer.

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

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

Tumor Microenvironment-"AND" Near-Infrared Light-Activated Coordination Polymer Nanoprodrug for On-Demand CO-Sensitized Synergistic Cancer Therapy

Carbon monoxide (CO) as an emerging treatment holds great promise for inducing the apoptosis of cancer cells. Here coordination assembled strategy is first reported for synthesis of Cu(II)-flavone coordination polymer (NCu-FleCP) CO nanoprodrug that is stable in normal physiological conditions, and yet readily reduces to small size prodrug complex and releases CO on demand under glutathione (GSH) and near infrared (NIR) light. Specifically, after uptaking by cancer cells, local GSH attacked coordination bond within NCu-FleCP, resulting in the release of Cu(I) and free Fle. The CC bond of Fle is cleavage under NIR light to release CO for gas therapy, and Cu(I) reacts with local H₂ O₂ through Fenton like reaction to generate hydroxyl radicals (^• OH) for chemodynamic therapy. Detailed in vitro and in vivo experiments demonstrate that the CO prodrug system in generating a sufficient quantity of CO and ^• OH offers remarkable destructive effects against cancer cells without causing toxicity to surrounding normal tissues. The study provides a solid foundation to develop smart coordination polymer CO prodrugs with on-demand CO release, enhanced permeability and retention effect, and biodegradability for multimodal synergistic therapy.

Expanding the Limits of Photodynamic Therapy: The Design of Organelles and Hypoxia-Targeting Nanomaterials for Enhanced Photokilling of Cancer

Photodynamic therapy (PDT) is a minimally invasive clinical protocol that combines a nontoxic photosensitizer (PS), appropriate visible light, and molecular oxygen for cancer treatment. This triad generates reactive oxygen species (ROS) in situ, leading to different cell death pathways and limiting the arrival of nutrients by irreversible destruction of the tumor vascular system. Despite the number of formulations and applications available, the advancement of therapy is hindered by some characteristics such as the hypoxic condition of solid tumors and the limited energy density (light fluence) that reaches the target. As a result, the use of PDT as a definitive monotherapy for cancer is generally restricted to pretumor lesions or neoplastic tissue of approximately 1 cm in size. To expand this limitation, researchers have synthesized functional nanoparticles (NPs) capable of carrying classical photosensitizers with self-supplying oxygen as well as targeting specific organelles such as mitochondria and lysosomes. This has improved outcomes in vitro and in vivo. This review highlights the basis of PDT, many of the most commonly used strategies of functionalization of smart NPs, and their potential to break the current limits of the classical protocol of PDT against cancer. The application and future perspectives of the multifunctional nanoparticles in PDT are also discussed in some detail.

Reduction of oxidative stress and ornithine decarboxylase expression in a human prostate cancer cell line PC-3 by a combined treatment with α-tocopherol and naringenin

Differentiation of a human aggressive PC-3 cancer cell line was obtained, in a previous investigation, by the synergic effect of α-tocopherol (α-TOC) and naringenin (NG). This combined treatment induced apoptosis and subsequent reduction of the PC-3 cell proliferation and invasion, by a pro-differentiating action. Since one of the peculiar characteristics of NG and α-TOC is their strong antioxidant activity, this study aimed to investigate their potential effect on the activity of the main enzymes involved in the antioxidant mechanism in prostate cancer cells. NG and α-TOC administered singularly or combined in the PC-3 cell line, affected the activity of several enzymes biomarkers of the cellular antioxidant activity, as well as the concentration of total glutathione (GSH + GSSG) and thiobarbituric acid reactive substances (TBARS). The combined treatment increased the TBARS levels and superoxide dismutase (SOD) activity, while decreased the glutathione S-transferase (GST), glutathione reductase (GR), and glyoxalase I (GI) activities. The results obtained indicate that a combined treatment with these natural compounds mitigated the oxidative stress in the human PC-3 cell line. In addition, a significant reduction of both ornithine decarboxylase (ODC) expression and intracellular levels of polyamines, both well-known positive regulators of cell proliferation, accompanied the reduction of oxidative stress observed in the combined α-TOC and NG treatment. Considering the established role of polyamines in cell differentiation, the synergism with NG makes α-TOC a potential drug for further study on the differentiation therapy in prostate cancer patients.

Sustained IKKβ phosphorylation and NF-κB activation by superoxide-induced peroxynitrite-mediated nitrotyrosine modification of B56γ3 and PP2A inactivation

Apart from its physiological role in inflammation and immunity, the nuclear factor-kappa B (NF-κB) protein complex has been implicated in tumorigenesis and its progression. Here, we provide evidence that a pro-oxidant milieu is an upstream effector of oncogenic NF-κB signaling. Through pharmacological or genetic inhibition of SOD1, we show that elevated intracellular superoxide (O₂•^-) mediates sustained IKK phosphorylation, and induces downstream degradation of IκBα, leading to the nuclear localization and transcriptional activation of NF-κB. Mechanistically, we show that such sustained NF-κB signaling is a function of protein phosphatase 2A (PP2A) inactivation brought about by the nitrative modification of its substrate-binding sub-unit B56γ. Importantly, the pro-oxidant driven NF-κB activation enhances the migratory and invasive potential of cancer cells. In summary, our work highlights the critical involvement of O₂•^--dependent peroxynitrite production in inhibiting PP2A-mediated dephosphorylation of IKK, thereby facilitating cancers to acquire an invasive phenotype. Given that NF-κB is a key player of chronic inflammation and carcinogenesis, our work unravels a novel synergistic node involving O₂•^--driven redox milieu and deregulated PP2A as a potential therapeutic target.

NOX2-Derived Reactive Oxygen Species in Cancer

The formation of reactive oxygen species (ROS) by the myeloid cell NADPH oxidase NOX2 is critical for the destruction of engulfed microorganisms. However, recent studies imply that ROS, formed by NOX2⁺ myeloid cells in the malignant microenvironment, exert multiple actions of relevance to the growth and spread of neoplastic cells. By generating ROS, tumor-infiltrating myeloid cells and NOX2⁺ leukemic myeloid cells may thus (i) compromise the function and viability of adjacent cytotoxic lymphocytes, including natural killer (NK) cells and T cells, (ii) oxidize DNA to trigger cancer-promoting somatic mutations, and (iii) affect the redox balance in cancer cells to control their proliferation and survival. Here, we discuss the impact of NOX2-derived ROS for tumorigenesis, tumor progression, regulation of antitumor immunity, and metastasis. We propose that NOX2 may be a targetable immune checkpoint in cancer.

2-Naphthol Moiety of Neocarzinostatin Chromophore as a Novel Protein-Photodegrading Agent and Its Application as a H2 O2 -Activatable Photosensitizer

A 2-naphthol derivative 2 corresponding to the aromatic ring moiety of neocarzinostatin chromophore was found to degrade proteins under photo-irradiation with long-wavelength UV light without any additives under neutral conditions. Structure-activity relationship studies of the derivative revealed that methylation of the hydroxyl group at the C2 position of 2 significantly suppressed its photodegradation ability. Furthermore, a purpose-designed synthetic tumor-related biomarker, a H₂ O₂ -activatable photosensitizer 8 possessing a H₂ O₂ -responsive arylboronic ester moiety conjugated to the hydroxyl group at the C2 position of 2, showed significantly lower photodegradation ability compared to 2. However, release of the 2 from 8 by reaction with H₂ O₂ regenerated the photodegradation ability. Compound 8 exhibited selective photo-cytotoxicity against high H₂ O₂ -expressing cancer cells upon irradiation with long-wavelength UV light.

Differential regulation of mitochondrial complex I and oxidative stress based on metastatic potential of colorectal cancer cells

Mitochondria serve a vital role in cellular homeostasis as they regulate cell proliferation and death pathways, which are attributed to mitochondrial bioenergetics, free radicals and metabolism. Alterations in mitochondrial functions have been reported in various diseases, including cancer. Colorectal cancer (CRC) is one of the most common metastatic cancer types with high mortality rates. Although mitochondrial oxidative stress has been associated with CRC, its specific mechanism and contribution to metastatic progression remain poorly understood. Therefore, the aims of the present study were to investigate the role of mitochondria in CRC cells with low and high metastatic potential and to evaluate the contribution of mitochondrial respiratory chain (RC) complexes in oncogenic signaling pathways. The present results demonstrated that cell lines with low metastatic potential were resistant to mitochondrial complex I (C-I)-mediated oxidative stress, and had C-I inhibition with impaired mitochondrial functions. These adaptations enabled cells to cope with higher oxidative stress. Conversely, cells with high metastatic potential demonstrated functional C-I with improved mitochondrial function due to coordinated upregulation of mitochondrial biogenesis and metabolic reprogramming. Pharmacological inhibition of C-I in high metastatic cells resulted in increased sensitivity to cell death and decreased metastatic signaling. The present findings identified the differential regulation of mitochondrial functions in CRC cells, based on CRC metastatic potential. Specifically, it was suggested that a functional C-I is required for high metastatic features of cancer cells, and the role of C-I could be further examined as a potential target in the development of novel therapies for diagnosing high metastatic cancer types.

Roles of Reactive Oxygen Species in Biological Behaviors of Prostate Cancer

Prostate cancer (PCa), known as a heterogenous disease, has a high incidence and mortality rate around the world and seriously threatens public health. As an inevitable by-product of cellular metabolism, reactive oxygen species (ROS) exhibit beneficial effects by regulating signaling cascades and homeostasis. More and more evidence highlights that PCa is closely associated with age, and high levels of ROS are driven through activation of several signaling pathways with age, which facilitate the initiation, development, and progression of PCa. Nevertheless, excessive amounts of ROS result in harmful effects, such as genotoxicity and cell death. On the other hand, PCa cells adaptively upregulate antioxidant genes to detoxify from ROS, suggesting that a subtle balance of intracellular ROS levels is required for cancer cell functions. The current review discusses the generation and biological roles of ROS in PCa and provides new strategies based on the regulation of ROS for the treatment of PCa.

The Future of Anticancer Drugs: A Cytotoxicity Assessment Study of CdSe/ZnS Quantum Dots

Quantum dots (QDs), including CdSe/ZnS, are nanoparticles emitting various wavelengths of fluorescent light depending on their size. Fluorescence allows them to be exploited for in vivo sensing/imaging of cancer cells. Nevertheless, thorough assessments of the effects of these commonly used QDs on cell stability are essentially required prior to their full applications. To investigate the effects of Cd QDs on the growth of human cervical cancer cells (HeLa), we utilized a growth assay, a reactive oxygen species (ROS) assay, an apoptosis assay, and RNA-seq. The growth assay results showed significant proliferation inhibition of HeLa cells by CdSe/ZnS. We revealed that smaller green CdSe/ZnS exerts more toxic effects than slightly larger yellow CdSe/ZnS. There were no significant increases of ROSs under the treatment of Cd QDs, which is consistent with the notion that low concentration of Cd QDs does not cause significant production of ROSs. In addition, we found that Cd QDs induced late apoptosis. RNA-Seq-based transcriptome analysis revealed that the exposure to green Cd QDs significantly upregulated antiapoptotic, antiproliferative, and antitumorigenic functions. The transcriptome profile also noted the downregulation of pro-proliferation, mitochondrial respiratory chain, detoxification, and receptor-mediated endocytosis. Taken together, our findings provide evidence that green CdSe/ZnS can be an alternative anticancer drug. In addition, our transcriptome analysis provides new insights into alteration of physiological state induced by CdSe/ZnS QDs in HeLa cancer cells.

A pyrene-based ratiometric fluorescent probe with a large Stokes shift for selective detection of hydrogen peroxide in living cells

Hydrogen peroxide (H₂O₂) plays a significant role in regulating a variety of biological processes. Dysregulation of H₂O₂ can lead to various diseases. Although numerous fluorescent imaging probes for H₂O₂ have been reported, the development of H₂O₂ ratiometric fluorescent probe with large Stokes shift remains rather limited. Such probes have shown distinct advantages, such as minimized interference from environment and improved signal-to noise ratio. In this work, we reported a new pyrene-based compound Py-VPB as H₂O₂ fluorescent probe in vitro. The probe demonstrated ratiometric detection behavior, large Stokes shift and large emission shift. In addition, the probe showed high sensitivity and selectivity towards H₂O₂ in vitro. Based on these excellent properties, we successfully applied Py-VPB to the visualization of exogenous and endogenous H₂O₂ in living cells. Cell imaging study also showed that our probe was localized in the mitochondria. We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H₂O₂ in living systems.

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The first pyrene-based fluorescent probe for H₂O₂ detection with ratiometric readout was presented.

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The probe has shown prominent properties in detecting H₂O₂, such as high sensitivity & selectivity and large Stokes shift.

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The probe was successfully applied to visualizing exogenous and endogenous H₂O₂ in living cells.

NADPH Oxidase 5 upregulation is associated with lymphoma aggressiveness

OBJECTIVES

Lymphomas are a heterogeneous set of malignant neoplasias of lymphoid B and NK/T mature and immature cells at various stages of differentiation. Genetic and molecular biology tools are used to appropriately classify the type and prognosis of the lymphomas, which have implications in therapeutic effectiveness. Among them, the nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) oxidase (NOX5) enzymes have been explored. This study analyzed the expression of NADPH oxidase 5 in lymphoma tissue according to the degree of tumor aggressiveness.

METHODS

Slides from 64 patients with lymphoma who had paraffin-embedded tissue available were reviewed by two independent, experienced pathologists. They classified tumors according to the WHO classification (2017). NOX5 expression in tissues was assessed by immunohistochemical staining using a tissue microarray. The assay was interpreted using a scoring system of 0, 1, 2, and 3, for cytoplasmic staining of NOX5 corresponding to negative, weak, intermediate, and strong staining, respectively. We compared the expression of NOX5 in patients with aggressive versus non-aggressive lymphomas.

RESULTS

NOX5 expression was positive in 100% (27/27) of aggressive lymphomas and in 19% (7/37) of non-aggressive ones. The seven patients with positive expression of NOX5 presented intermediate staining (2); strong staining (3) was observed only in tissues of aggressive lymphomas, and negative and weak staining (0 and 1) were observed only in non-aggressive lymphomas.

CONCLUSIONS

Aggressive lymphomas overexpress NOX5 protein. The higher NOX5 expression in aggressive lymphomas can suggest an involvement of this enzyme on the acquisition of an aggressive phenotype in lymphoid neoplasia.

NADPH oxidase 1 is highly expressed in human large and small bowel cancers

To facilitate functional investigation of the role of NADPH oxidase 1 (NOX1) and associated reactive oxygen species in cancer cell signaling, we report herein the development and characterization of a novel mouse monoclonal antibody that specifically recognizes the C-terminal region of the NOX1 protein. The antibody was validated in stable NOX1 overexpression and knockout systems, and demonstrates wide applicability for Western blot analysis, confocal microscopy, flow cytometry, and immunohistochemistry. We employed our NOX1 antibody to characterize NOX1 expression in a panel of 30 human colorectal cancer cell lines, and correlated protein expression with NOX1 mRNA expression and superoxide production in a subset of these cells. Although a significant correlation between oncogenic RAS status and NOX1 mRNA levels could not be demonstrated in colon cancer cell lines, RAS mutational status did correlate with NOX1 expression in human colon cancer surgical specimens. Immunohistochemical analysis of a comprehensive set of tissue microarrays comprising over 1,200 formalin-fixed, paraffin-embedded tissue cores from human epithelial tumors and inflammatory disease confirmed that NOX1 is overexpressed in human colon and small intestinal adenocarcinomas, as well as adenomatous polyps, compared to adjacent, uninvolved intestinal mucosae. In contradistinction to prior studies, we did not find evidence of NOX1 overexpression at the protein level in tumors versus histologically normal tissues in prostate, lung, ovarian, or breast carcinomas. This study constitutes the most comprehensive histopathological characterization of NOX1 to date in cellular models of colon cancer and in normal and malignant human tissues using a thoroughly evaluated monoclonal antibody. It also further establishes NOX1 as a clinically relevant therapeutic target in colorectal and small intestinal cancer.

A Tailored Multifunctional Anticancer Nanodelivery System for Ruthenium-Based Photosensitizers: Tumor Microenvironment Adaption and Remodeling

Ruthenium complexes are promising photosensitizers (PSs), but their clinical applications have many limitations. Here, a multifunctional nano-platform PDA-Pt-CD@RuFc formed by platinum-decorated and cyclodextrin (CD)-modified polydopamine (PDA) nanoparticles (NPs) loaded with a ferrocene-appended ruthenium complex (RuFc) is reported. The NPs can successfully deliver RuFc to the tumor sites. The release of RuFc from the NPs can be triggered by low pH, photothermal heating, and H2O2. The combined photodynamic and photothermal therapy (PDT-PTT) mediated by PDA-Pt-CD@RuFc NPs can overcome the hypoxic environment of tumors from several aspects. First, the platinum NPs can catalyze H2O2 to produce O2. Second, vasodilation caused by photothermal heating can sustain the oxygen supplement. Third, PDT exerted by RuFc can also occur through the non-oxygen-dependent Fenton reaction. Due to the presence of PDA, platinum NPs, and RuFc, the nanosystem can be used in multimodal imaging including photothermal, photoacoustic, and computed tomography imaging. The NPs can be excited by the near-infrared two-photon light source. Moreover, the combined treatment can improve the tumor microenvironments to obtain an optimized combined therapeutic effect. In summary, this study presents a tumor-microenvironment-adaptive strategy to optimize the potential of ruthenium complexes as PSs from multiple aspects.

A Strategy of Killing Three Birds with One Stone for Cancer Therapy through Regulating the Tumor Microenvironment by H2O2-Responsive Gene Delivery System

Constructing an efficient in vivo gene delivery system has always been extremely challenging. Herein, a highly efficient H₂O₂-responsive in vivo polycationic gene delivery system is developed for the first time. The efficient vector PLL-RT (i.e., polylysine grafted with p-tosyl-l-arginine) is used to mediate plasmid DNA (pDNA) delivery, and H₂O₂-responsive thioketal dipropanedioic acid-modified dextran (TDPAD) is used as a shielding system for effectively coating vector/pDNA polyplexes. The constructed gene delivery system exhibits a prolonged circulatory half-life in vivo and accelerates the accumulation of vector/DNA polyplexes in tumor tissue by the enhanced permeability and retention (EPR) effect. Moreover, this gene delivery system exhibits highly efficient and synergistic antitumor effects through a strategy of killing three birds with one stone. First, upon the arrival of TDPAD/PLL-RT/pDNA [abbreviated as T(PD)] at the tumor site by the EPR effect, TDPAD reacts with excess H₂O₂ in tumor tissue, contributing to the detachment of TDPAD, and PLL-RT then mediates the enhanced endocytosis of pDNA encoding shVEGF and significantly downregulates the expression of vascular endothelial growth factor (VEGF) in tumor tissue, exhibiting an outstanding antitumor effect. Second, the H₂O₂ consumption by TDPAD significantly decreases the H₂O₂ level in tumor tissue, which synergistically suppresses tumor growth. Third, small-molecule product mercaptopropionic acid, generated by the reaction of TDPAD with H₂O₂, can induce cancer cell apoptosis and exert pronounced antitumor efficacy. This polycationic gene delivery system shows negligible toxicity in vitro and in vivo. This strategy provides an ideal platform for constructing an efficient in vivo gene delivery system and has bright prospects for cancer therapy.

JQ1-Loaded Polydopamine Nanoplatform Inhibits c-MYC/Programmed Cell Death Ligand 1 to Enhance Photothermal Therapy for Triple-Negative Breast Cancer

Programmed cell death ligand 1 (PD-L1) blockade has achieved great success in cancer immunotherapy; however, the response of triple-negative breast cancer (TNBC) to PD-L1 antibodies is limited. To address this challenge, we use the bromodomain and extra-terminal inhibitor JQ1 to down-regulate the expression of PD-L1 and thus elicit the immune response to TNBC instead of using antibodies to block PD-L1. JQ1 also inhibits the growth of TNBC as a targeted therapeutic agent by inhibiting the BRD4-c-MYC axis. The polydopamine nanoparticles (PDMNs) are introduced as a biodegradable and adaptable platform to load JQ1 and induce photothermal therapy (PTT) as another synergistic therapeutic modality. Because the JQ1-loaded PDMNs (PDMN-JQ1) are self-degradable and release JQ1 continuously, this synergistic treatment can lead to remarkable activation of cytotoxic T lymphocytes and induce a strong immune-memory effect to protect mice from tumor re-challenge. Taken together, our study demonstrates a compact and simple nanoplatform for triple therapy, including targeted therapy, PTT, and immunotherapy, for TNBC treatment.

Role of Reactive Oxygen Species in Cancer Progression: Molecular Mechanisms and Recent Advancements

Reactive oxygen species (ROS) play a pivotal role in biological processes and continuous ROS production in normal cells is controlled by the appropriate regulation between the silver lining of low and high ROS concentration mediated effects. Interestingly, ROS also dynamically influences the tumor microenvironment and is known to initiate cancer angiogenesis, metastasis, and survival at different concentrations. At moderate concentration, ROS activates the cancer cell survival signaling cascade involving mitogen-activated protein kinase/extracellular signal-regulated protein kinases 1/2 (MAPK/ERK1/2), p38, c-Jun N-terminal kinase (JNK), and phosphoinositide-3-kinase/ protein kinase B (PI3K/Akt), which in turn activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), matrix metalloproteinases (MMPs), and vascular endothelial growth factor (VEGF). At high concentrations, ROS can cause cancer cell apoptosis. Hence, it critically depends upon the ROS levels, to either augment tumorigenesis or lead to apoptosis. The major issue is targeting the dual actions of ROS effectively with respect to the concentration bias, which needs to be monitored carefully to impede tumor angiogenesis and metastasis for ROS to serve as potential therapeutic targets exogenously/endogenously. Overall, additional research is required to comprehend the potential of ROS as an effective anti-tumor modality and therapeutic target for treating malignancies.