Oxidative Stress in Cancer Immunotherapy: Molecular Mechanisms and Potential Applications

The effect of physical activity on markers of oxidative and antioxidant stress in cancer patients: a systematic review and meta-analysis

BACKGROUND

Prescribing physical exercise as part of the clinical treatment of cancer patients has become an important strategy in the therapeutic arsenal available in the main health centers specialized in neoplastic diseases, but there is still uncertainty regarding the role of regular physical activity in modifying oxidative stress markers and antioxidants, as high levels of oxidative stress can lead to the development of carcinogens. Therefore, we assessed the effect of physical activity versus absence of physical activity on markers of oxidative stress and antioxidants in cancer patients.

METHODS

We looked for randomized controlled trials that included adult with any type of cancer performing some physical activity and compared them to a control group of cancer patients with no physical activity. The outcomes of interest collected were markers of oxidative stress and antioxidants. Six databases were used for the search (EMBASE, The Cochrane Library (CENTRAL), US National Library of Medicine (PubMed), Physiotherapy Evidence Database (PEDro), Cumulative Index of Nursing and Allied Health (CINAHL) and SPORTDiscus via EBSCO) until January 31st, 2024.

RESULTS

In the end, 7 randomized controlled clinical trials were included, totaling 573 participants. It was possible to conduct a meta-analysis with demonstrated that physical activity potentially increases the antioxidant marker Trolox, Taoc, Gpx, (SMD = 1.23, CI: 0.13 to 2.34). However, these findings were classified as having very low to moderate GRADE evidence.

CONCLUSION

Cancer patients who participated in physical activity programs may have exhibited an increased concentration of antioxidants. Although the overall quality of the evidence in the studies was very low, these findings represent an important field of research that should be guided by studies with more participants and homogeneous methods of analysis of oxidant stress and antioxidant markers.

TRIAL REGISTRATION

PROSPERO CRD42021257815.

Zwitterionic, Stimuli-Responsive Liposomes for Curcumin Drug Delivery: Enhancing M2 Macrophage Polarization and Reducing Oxidative Stress through Enzyme-Specific and Hyperthermia-Triggered Release

A zwitterionic, stimuli-responsive liposomal system was meticulously designed for the precise and controlled delivery of curcumin, leveraging enzyme-specific and hyperthermic stimuli to enhance therapeutic outcomes. This platform is specifically engineered to release curcumin in response to phospholipase A2, an enzyme that degrades phospholipids, enabling highly targeted and site-specific drug release. Mild hyperthermia (40 °C) further enhances membrane permeability and activates thermosensitive carriers, optimizing drug delivery. Curcumin encapsulation is facilitated through a combination of zwitterionic and electrostatic interactions, significantly improving both loading capacity and encapsulation efficiency. A design of experiments (DoE) approach was employed to systematically optimize lipid-to-cholesterol ratios and formulation conditions. The liposomal system was thoroughly characterized using dynamic light scattering, zeta potential measurements, and transmission electron microscopy, ensuring stability and structural integrity. Notably, this system effectively encapsulates hydrophobic curcumin while maintaining particle size and bioactivity. In vitro studies revealed robust antioxidant and anti-ROS activities, alongside excellent biocompatibility, with no cytotoxicity observed at concentrations up to 2000 μg/mL. Furthermore, the zwitterionic liposomes enhanced M2 macrophage polarization and reduced oxidative stress. This advanced platform offers a promising, biocompatible solution for targeted curcumin delivery.

The identification of heterogeneous reactive oxygen subtypes in esophageal squamous cell carcinoma to aid patient prognosis and immunotherapy

Introduction

Esophageal cancer is increasingly recognized as a significant global malignancy. The main pathological subtype of this cancer is esophageal squamous cell carcinoma (ESCC), which displays a higher degree of malignancy and a poorer prognosis. Reactive oxygen species (ROS) play a critical role in modulating the immune response to tumors, and understanding the regulation of ROS in ESCC could lead to novel and improved therapeutic strategies for ESCC patients.

Methods

A consensus matrix derived from genes involved in the ROS pathway revealed two subtypes of ROS. These subtypes were categorized as ROS-active or ROS-suppressive based on their level of ROS activity. The heterogeneity among the different ROS subtypes was then explored from various perspectives, including gene function, immune response, genomic stability, and immunotherapy. In order to assess the prognosis and the potential benefits of immunotherapy, a ROS activity score (RAS) was developed using the identified ROS subtypes. In vitro experiments were performed to confirm the impact of core RAS genes on the proliferative activity of esophageal cancer cell lines.

Results

Two distinctive subtypes of ROS were identified. The first subtype, referred to as ROS-active, exhibited elevated ROS activity, enhanced involvement in cancer-associated immune pathways, and increased infiltration of effector immune cells. The second subtype, named ROS-suppressive, demonstrated weaker ROS activity but displayed more pronounced dysregulation in the cell cycle and a denser extracellular matrix, indicating malignant characteristics. Genomic stability, particularly in terms of copy number variation (CNV) events, differed between the two ROS subtypes. By developing a RAS model, reliable risk assessment for overall survival (OS) in patients with ESCC was achieved, and the model demonstrated strong predictive capabilities in real-world immunotherapy cohorts. Moreover, the core gene LDLRAD1 within the RAS model was found to enhance proliferative activity in esophageal cancer cell lines.

Conclusion

Based on the ROS pathway, we successfully identified two distinct subtypes in ESCC: the ROS-active subtype and the ROS-suppressive subtype. These subtypes were utilized to evaluate prognosis and the sensitivity to immunotherapy.

Hybrid nano-stimulator for specific amplification of oxidative stress and precise tumour treatment

BACKGROUND

The use of reactive oxygen species (ROS) to target cancer cells has become a hot topic in tumor therapy.

PURPOSE

Although ROS has strong cytotoxicity against tumor cells, the key issue currently is how to generate a large amount of ROS within tumor cells.

METHODS

Organic/inorganic hybrid nanoreactor materials combine the advantages of organic and inorganic components and can amplify cancer treatment by increasing targeting and material self-action. The multifunctional organic / inorganic hybrid nanoreactor is helpful to overcome the shortcomings of current reactive oxygen species in cancer treatment. It can realize the combination of in situ dynamic therapy and immunotherapy strategies, and has a synergistic anti-tumor effect.

RESULTS

This paper reviews the research progress of organic/inorganic hybrid nanoreactor materials using tumor components to amplify reactive oxygen species for cancer treatment. The article reviews the tumor treatment strategies of nanohybrids from the perspectives of cancer cells, immune cells, tumor microenvironment, as well as 3D printing and electrospinning techniques, which are different from traditional nanomaterial technologies, and will arouse interest among scientists in tumor therapy and nanomedicine.

Metabolic reprograming mediated by tumor cell-intrinsic type I IFN signaling is required for CD47-SIRPα blockade efficacy

Type I interferons have been well recognized for their roles in various types of immune cells during tumor immunotherapy. However, their direct effects on tumor cells are less understood. Oxidative phosphorylation is typically latent in tumor cells. Whether oxidative phosphorylation can be targeted for immunotherapy remains unclear. Here, we find that tumor cell responsiveness to type I, but not type II interferons, is essential for CD47-SIRPα blockade immunotherapy in female mice. Mechanistically, type I interferons directly reprogram tumor cell metabolism by activating oxidative phosphorylation for ATP production in an ISG15-dependent manner. ATP extracellular release is also promoted by type I interferons due to enhanced secretory autophagy. Functionally, tumor cells with genetic deficiency in oxidative phosphorylation or autophagy are resistant to CD47-SIRPα blockade. ATP released upon CD47-SIRPα blockade is required for antitumor T cell response induction via P2X7 receptor-mediated dendritic cell activation. Based on this mechanism, combinations with inhibitors of ATP-degrading ectoenzymes, CD39 and CD73, are designed and show synergistic antitumor effects with CD47-SIRPα blockade. Together, these data reveal an important role of type I interferons on tumor cell metabolic reprograming for tumor immunotherapy and provide rational strategies harnessing this mechanism for enhanced efficacy of CD47-SIRPα blockade.

Generation of Hydrogen Peroxide in Cancer Cells: Advancing Therapeutic Approaches for Cancer Treatment

Cancer cells show altered antioxidant defense systems, dysregulated redox signaling, and increased generation of reactive oxygen species (ROS). Targeting cancer cells through ROS-mediated mechanisms has emerged as a significant therapeutic strategy due to its implications in cancer progression, survival, and resistance. Extensive research has focused on selective generation of H2O2 in cancer cells for selective cancer cell killing by employing various strategies such as metal-based prodrugs, photodynamic therapy, enzyme-based systems, nano-particle mediated approaches, chemical modulators, and combination therapies. Many of these H2O2-amplifying approaches have demonstrated promising anticancer effects and selectivity in preclinical investigations. They selectively induce cytotoxicity in cancer cells while sparing normal cells, sensitize resistant cells, and modulate the tumor microenvironment. However, challenges remain in achieving selectivity, addressing tumor heterogeneity, ensuring efficient delivery, and managing safety and toxicity. To address those issues, H2O2-generating agents have been combined with other treatments leading to optimized combination therapies. This review focuses on various chemical agents/approaches that kill cancer cells via H2O2-mediated mechanisms. Different categories of compounds that selectively generate H2O2 in cancer cells are summarized, their underlying mechanisms and function are elucidated, preclinical and clinical studies as well as recent advancements are discussed, and their prospects as targeted therapeutic agents and their therapeutic utility in combination with other treatments are explored. By understanding the potential of these compounds, researchers can pave the way for the development of effective and personalized cancer treatments.

The combination of calreticulin-targeting L-ASNase and anti-PD-L1 antibody modulates the tumor immune microenvironment to synergistically enhance the antitumor efficacy of radiotherapy

Radiotherapy (RT) triggers immunogenic cell death (ICD). L-ASNase, which catalyzes the conversion of asparagine (Asn), thereby depleting it, is used in the treatment of blood cancers. In previous work, we showed that CRT3LP and CRT4LP, PASylated L-ASNases conjugated to the calreticulin (CRT)-specific monobodies CRT3 and CRT4, increase the efficacy of ICD-inducing chemotherapy. Here, we assessed their efficacy in tumor-bearing mice treated with RT. Methods: Monobody binding was evaluated by in silico molecular docking analysis. The expression and cellular localization of ecto-CRT were assessed by confocal imaging and flow cytometry. The antitumor effect and the roles of CRT3LP and CRT4LP in irradiation (IR)-induced ICD in tumors were analyzed by ELISA, immunohistochemistry, and immune analysis methods. Results: Molecular docking analysis showed that CRT3 and CRT4 monobodies were stably bound to CRT. Exposure to 10 Gy IR decreased the viability of CT-26 and MC-38 tumor cells in a time-dependent manner until 72 h, and increased the expression of the ICD marker ecto-CRT (CRT exposed on the cell surface) and the immune checkpoint marker PD-L1 until 48 h. IR enhanced the cytotoxicity of CRT3LP and CRT4LP in CT-26 and MC-38 tumor cells, and increased reactive oxygen species (ROS) levels. In mice bearing CT-26 and MC-38 subcutaneous tumors treated with 6 Gy IR, Rluc8-conjugated CRT-specific monobodies (CRT3-Rluc8 and CRT4-Rluc8) specifically targeted tumor tissues, and CRT3LP and CRT4LP increased total ROS levels in tumor tissues, thereby enhancing the antitumor efficacy of RT. Tumor tissues from these mice showed increased mature dendritic, CD4+ T, and CD8+ T cells and pro-inflammatory cytokines (IFNγ and TNFα) and decreased regulatory T cells, and the expression of tumor cell proliferation markers (Ki67 and CD31) was downregulated. These data indicate that the combination of IR and CRT-targeting L-ASNases activated and reprogramed the immune system of the tumor microenvironment. Consistent with these data, an immune checkpoint inhibitor (anti-PD-L1 antibody) markedly increased the therapeutic efficacy of combined IR and CRT-targeting L-ASNases. Conclusion: CRT-specific L-ASNases are useful as additive drug candidates in tumors treated with RT, and combination treatment with anti-PD-L1 antibody increases their therapeutic efficacy.

Dynamic immuno-nanomedicines in oncology

Anti-cancer therapeutics have achieved significant advances due to the emergence of immunotherapies that rely on the identification of tumors by the patients' immune system and subsequent tumor eradication. However, tumor cells often escape immunity, leading to poor responsiveness and easy tolerance to immunotherapy. Thus, the potentiated anti-tumor immunity in patients resistant to immunotherapies remains a challenge. Reactive oxygen species-based dynamic nanotherapeutics are not new in the anti-tumor field, but their potential as immunomodulators has only been demonstrated in recent years. Dynamic nanotherapeutics can distinctly enhance anti-tumor immune response, which derives the concept of the dynamic immuno-nanomedicines (DINMs). This review describes the pivotal role of DINMs in cancer immunotherapy and provides an overview of the clinical realities of DINMs. The preclinical development of emerging DINMs is also outlined. Moreover, strategies to synergize the antitumor immunity by DINMs in combination with other immunologic agents are summarized. Last but not least, the challenges and opportunities related to DINMs-mediated immune responses are also discussed.

Integrating machine learning algorithms to systematically assess reactive oxygen species levels to aid prognosis and novel treatments for triple -negative breast cancer patients

Introduction

Breast cancer has become one of the top health concerns for women, and triple-negative breast cancer (TNBC) leads to treatment resistance and poor prognosis due to its high degree of heterogeneity and malignancy. Reactive oxygen species (ROS) have been found to play a dual role in tumors, and modulating ROS levels may provide new insights into prognosis and tumor treatment.

Methods

This study attempted to establish a robust and valid ROS signature (ROSig) to aid in assessing ROS levels. The driver ROS prognostic indicators were searched based on univariate Cox regression. A well-established pipeline integrating 9 machine learning algorithms was used to generate the ROSig. Subsequently, the heterogeneity of different ROSig levels was resolved in terms of cellular communication crosstalk, biological pathways, immune microenvironment, genomic variation, and response to chemotherapy and immunotherapy. In addition, the effect of the core ROS regulator HSF1 on TNBC cell proliferation was detected by cell counting kit-8 and transwell assays.

Results

A total of 24 prognostic ROS indicators were detected. A combination of the Coxboost+ Survival Support Vector Machine (survival-SVM) algorithm was chosen to generate ROSig. ROSig proved to be the superior risk predictor for TNBC. Cellular assays show that knockdown of HSF1 can reduce the proliferation and invasion of TNBC cells. The individual risk stratification based on ROSig showed good predictive accuracy. High ROSig was identified to be associated with higher cell replication activity, stronger tumor heterogeneity, and an immunosuppressive microenvironment. In contrast, low ROSig indicated a more abundant cellular matrix and more active immune signaling. Low ROSig has a higher tumor mutation load and copy number load. Finally, we found that low ROSig patients were more sensitive to doxorubicin and immunotherapy.

Conclusion

In this study, we developed a robust and effective ROSig model that can be used as a reliable indicator for prognosis and treatment decisions in TNBC patients. This ROSig also allows a simple assessment of TNBC heterogeneity in terms of biological function, immune microenvironment, and genomic variation.

Targeting the Interplay of Independent Cellular Pathways and Immunity: A Challenge in Cancer Immunotherapy

Immunotherapy is a cancer treatment that exploits the capacity of the body's immune system to prevent, control, and remove cancer. Immunotherapy has revolutionized cancer treatment and significantly improved patient outcomes for several tumor types. However, most patients have not benefited from such therapies yet. Within the field of cancer immunotherapy, an expansion of the combination strategy that targets independent cellular pathways that can work synergistically is predicted. Here, we review some consequences of tumor cell death and increased immune system engagement in the modulation of oxidative stress and ubiquitin ligase pathways. We also indicate combinations of cancer immunotherapies and immunomodulatory targets. Additionally, we discuss imaging techniques, which are crucial for monitoring tumor responses during treatment and the immunotherapy side effects. Finally, the major outstanding questions are also presented, and directions for future research are described.

Recent Advances in Cellular Signaling Interplay between Redox Metabolism and Autophagy Modulation in Cancer: An Overview of Molecular Mechanisms and Therapeutic Interventions

Autophagy is a fundamental homeostatic process in which certain cellular components are ingested by double-membrane autophagosomes and then degraded to create energy or to maintain cellular homeostasis and survival. It is typically observed in nutrient-deprived cells as a survival mechanism. However, it has also been identified as a crucial process in maintaining cellular homeostasis and disease progression. Normal cellular metabolism produces reactive oxygen (ROS) and nitrogen species at low levels. However, increased production causes oxidative stress, which can lead to diabetes, cardiovascular diseases, neurological disorders, and cancer. It was recently shown that maintaining redox equilibrium via autophagy is critical for cellular responses to oxidative stress. However, little is understood about the molecular cancer processes that connect to the control of autophagy. In cancer cells, oncogenic mutations, carcinogens, and metabolic reprogramming cause increased ROS generation and oxidative stress. Recent studies have suggested that increased ROS generation activates survival pathways that promote cancer development and metastasis. Moreover, the relationship between metabolic programming and ROS in cancer cells is involved in redox homeostasis and the malignant phenotype. Currently, while the signaling events governing autophagy and how redox homeostasis affects signaling cascades are well understood, very little is known about molecular events related to autophagy. In this review, we focus on current knowledge about autophagy modulation and the role of redox metabolism to further the knowledge of oxidative stress and disease progression in cancer regulation. Therefore, this review focuses on understanding how oxidation/reduction events fine-tune autophagy to help understand how oxidative stress and autophagy govern cancer, either as processes leading to cell death or as survival strategies for maintaining redox homeostasis in cancer.

Polyphenolic Boronates Inhibit Tumor Cell Proliferation: Potential Mitigators of Oxidants in the Tumor Microenvironment

Boronate-based compounds have been used in brain cancer therapy, either as prodrugs or in combination with other modalities. Boronates containing pro-luminescent and fluorescent probes have been used in mouse models of cancer. In this study, we synthesized and developed polyphenolic boronates and mitochondria-targeted polyphenolic phytochemicals (e.g., magnolol [MGN] and honokiol [HNK]) and tested their antiproliferative effects in brain cancer cells. Results show that mitochondria-targeted (Mito) polyphenolic boronates (Mito-MGN-B and Mito-HNK-B) were slightly more potent than Mito-MGN and Mito-HNK in inhibiting proliferation of the U87MG cell line. Similar proliferation results also were observed in other cancer cell lines, such as MiaPaCa-2, A549 and UACC-62. Independent in vitro experiments indicated that reactive nitrogen species (e.g., peroxynitrite) and reactive oxygen species (e.g., hydrogen peroxide) stoichiometrically react with polyphenolic boronates and Mito-polphenolic boronates, forming polyphenols and Mito-polyphenols as major products. Previous reports suggest that both Mito-MGN and Mito-HNK activate cytotoxic T cells and inhibit immunosuppressive immune cells. We propose that Mito-polyphenolic boronate-based prodrugs may be used to inhibit tumor proliferation and mitigate oxidant formation in the tumor microenvironment, thereby generating Mito-polyphenols in situ, as well as showing activity in the tumor microenvironment.

Oxidative stress indicators during the course of acute graft versus host disease

Aim: This prospective study aimed to observe the changes in oxidative stress indicators, including total anti-oxidant status (TAS), total oxidant status (TOS), paraoxanase-1 (PON1), total thiol (TT), native thiol (NT), disulphide (DS) and nitric oxide (NO) levels from sequential blood samples obtained during a de-novo episode of acute graft versus host disease (aGvHD) and evaluate their association with disease severity and the risk of steroid resistant disease. Material and Method: Sequential patients who underwent an allogeneic stem cell transplantation (ASCT) in our unit and subsequently developed a de-novo episode of aGvHD between January 2022 and May 2022 were included in case they gave informed consent. All patients were started high dose (2 mg/kg/day) methylprednisolone as institutional standard first-line treatment of aGvHD as soon as the clinical diagnosis is evident. All episodes were confirmed simultaneously with gastrointestinal (GI) endoscopy and/or skin biopsies. TAS, TOS, PON1, TT, NT, DS and NO were studied from blood samples collected on days 0, +3 and +7 of steroid treatment. Demographic characteristics, diagnoses, donor type, GvHD prophylaxis, stage and grade of aGvHD, performance status (PS), the presence of cytomegalovirus (CMV) reactivation and response to steroid therapy were also noted. Results: A total of 15 cases was included. The median age was 49 (23-77). Males constituted 60.0% (n=9). The most frequent diagnosis and donor type were acute leukemia (53.3%, n=8) and matched related donor (46.7%, n=7), respectively. High grade aGvHD with Glucksberg grading and International Bone Marrow Transplant Registry severity index (IBMTR-SI) included 53,3% (n=8) and 86.7% (n=10) of cases, respectively. Non-responders (20.0%, n=3) significantly had advanced stage GI involvement, higher grade of aGvHD with Glucksberg grading and IBMTR-SI, and lower PS (p=0.005, p=0.04, p=0.006, and p=0.02, respectively). The changes in TAS, TOS, PON1, TT, NT, DS and NO levels on days 0, +3 and +7 of steroid treatment were not significant. Median PON1 levels on days 0, +3 and +7 of steroid treatment were significantly lower among non-responders (p

Chicken skin-derived collagen peptides chelated zinc promotes zinc absorption and represses tumor growth and invasion in vivo by suppressing autophagy

To improve the utilization value of chicken by-products, we utilized the method of step-by-step hydrolysis with bromelain and flavourzyme to prepare low molecular weight chicken skin collagen peptides (CCP) (<5 kDa) and characterized the amino acids composition of the CCP. Then, we prepared novel CCP-chelated zinc (CCP–Zn) by chelating the CCP with ZnSO₄. We found that the bioavailability of CCP–Zn is higher than ZnSO₄. Besides, CCP, ZnSO₄, or CCP–Zn effectively repressed the tumor growth, invasion, and migration in a Drosophila malignant tumor model. Moreover, the anti-tumor activity of CCP–Zn is higher than CCP or ZnSO₄. Furthermore, the functional mechanism studies indicated that CCP, ZnSO₄, or CCP–Zn inhibits tumor progression by reducing the autonomous and non-autonomous autophagy in tumor cells and the microenvironment. Therefore, this research provides in vivo evidence for utilizing chicken skin in the development of zinc supplements and cancer treatment in the future.