High dose Vitamin C inhibits PD-L1 by ROS-pSTAT3 signal pathway and enhances T cell function in TNBC

Oxidative complexity: The role of ROS in the tumor environment and therapeutic implications

Reactive oxygen species (ROS) constitutes a group of reactive molecules that play a critical role in biological processes. Varying ROS levels have been frequently observed in cancer cells and the tumor microenvironment (TME). The role of ROS displays significant complexity in cancer development and therapy. Elevated ROS levels can induce metabolic reprogramming and promote the proliferation, invasion, and metastasis of cancer cells, resulting in cancer progression. However, excessive ROS accumulation leads to the occurrence of apoptosis, pyroptosis, necroptosis, and ferroptosis in cancer cells, which restrains tumor development. In the TME, ROS frequently promotes angiogenesis and remodels the extracellular matrix (ECM) by enhancing the differentiation of cancer-associated fibroblasts (CAFs), thereby supporting tumor growth. Concurrently, high ROS levels favour immunosuppressive cells, including M2-polarized macrophages, and regulatory T cells (Tregs), while impairing the antitumor capabilities of T cells. In the aspect of cancer therapy, it is overly simplistic to merely combine chemoradiotherapy with antioxidants as a therapeutic strategy. Instead, highlighting targeted therapies that modulate ROS is essential, given their inherent complexity. Fortunately, a variety of innovative treatments have emerged, including nanodrug delivery systems (NDDS), proteolysis-targeting chimeras (PROTAC), and adoptive cell therapy (ADT), which not only exhibit synergistic effects with immune checkpoint therapy (ICT), but also enhance the antitumor capabilities of the TME. In this paper, we elucidate the mechanism of ROS production, enumerate the role of ROS in cancer development and the TME, and discuss advancements in ROS-targeted cancer therapeutics.

Unveiling vitamin C: A new hope in the treatment of diffuse large B‑cell lymphoma (Review)

Lymphoma is a malignancy of the immune system, which originates from lymphatic tissues and lymph nodes. Diffuse large B‑cell lymphoma (DLBCL) is a common type of non‑Hodgkin lymphoma, occurring in 30‑40% of all cases, which has persistent clinical challenges. The treatment of DLBCL is challenging due to its diverse genetic and biological characteristics and complex clinical physiology. Despite advancements in overall prognosis, 20‑25% of patients continue to experience relapse and 10‑15% of patients experience refractory disease. Vitamin C is a water‑soluble vitamin with antioxidant properties and notable pharmacological activity, with potential applications in cancer therapy. Pharmacological doses of vitamin C (1‑4 g/kg) can induce apoptosis in malignant cells by inhibiting and/or reversing gene mutations that are associated with hematological malignancies. For example, 10‑25% of patients with myeloid malignancies have tet methylcytosine dioxygenase 2 (TET2) gene mutations and vitamin C can regulate blood stem cell frequency and leukemia production by enhancing TET2 function. Consequently, pharmacological doses of vitamin C can inhibit the development and progression of hematological malignancies. Therefore, the present review aimed to investigate the role of vitamin C in the pathophysiology and treatment of DLBCL, whilst highlighting the potential challenges and future perspectives.

Synergistic Activation of LEPR and ADRB2 Induced by Leptin Enhances Reactive Oxygen Specie Generation in Triple-Negative Breast Cancer Cells

PURPOSE

Leptin interacts not only with leptin receptor (LEPR) but also engages with other receptors. While the pro-oncogenic effects of the adrenergic receptor β2 (ADRB2) are well-established, the role of leptin in activating ADRB2 in triple-negative breast cancer (TNBC) remains unclear.

MATERIALS AND METHODS

The pro-carcinogenic effects of LEPR were investigated using murine TNBC cell lines, 4T1 and EMT6, and a tumor-bearing mouse model. Expression levels of LEPR, NADPH oxidase 4 (NOX4), and ADRB2 in TNBC cells and tumor tissues were analyzed via western blot and quantitative real-time polymerase chain reaction. Changes in reactive oxygen species (ROS) levels were assessed using flow cytometry and MitoSox staining, while immunofluorescence double-staining confirmed the co-localization of LEPR and ADRB2.

RESULTS

LEPR activation promoted NOX4-derived ROS and mitochondrial ROS production, facilitating TNBC cell proliferation and migration, effects which were mitigated by the LEPR inhibitor Allo-aca. Co-expression of LEPR and ADRB2 was observed on cell membranes, and bioinformatics data revealed a positive correlation between the two receptors. Leptin activated both LEPR and ADRB2, enhancing intracellular ROS generation and promoting tumor progression, which was effectively countered by a specific ADRB2 inhibitor ICI118551. In vivo, leptin injection accelerated tumor growth and lung metastases without affecting appetite, while treatments with Allo-aca or ICI118551 mitigated these effects.

CONCLUSION

This study demonstrates that leptin stimulates the growth and metastasis of TNBC through the activation of both LEPR and ADRB2, resulting in increased ROS production. These findings highlight LEPR and ADRB2 as potential biomarkers and therapeutic targets in TNBC.

High-dose Vitamin C inhibits PD-L1 expression by activating AMPK in colorectal cancer

Vitamin C (VitC) has elicited considerable interest regarding its potential role in cancer therapy; however, its effects on tumor immunity remain unclear. In colorectal cancer (CRC), although anti-PD-1/PD-L1 therapies demonstrate promise, their efficacy is still constrained. Our prior research demonstrated that VitC can inhibit tumor growth by suppressing the Warburg effect. This study aims to explore the effects of high-dose VitC on PD-L1 expression in CRC, focusing on its underlying mechanisms and potential for enhancing immunotherapy. We found that VitC inhibits aerobic glycolysis in HCT116 cells while also downregulating PD-L1 expression. Further investigations indicated that this process is mediated by VitC's activation of AMPK, which downregulates HK2 and NF-κB, ultimately resulting in reduced PD-L1 expression and increased T cell infiltration. Notably, we observed that VitC and the PD-L1 monoclonal antibody atezolizumab exhibit comparable tumor-inhibiting abilities, and their combined use further enhances this efficacy. In conclusion, our results demonstrate that high-dose VitC activates AMPK, downregulates PD-L1 expression, mitigates immune evasion, and suppresses tumor growth. This provides a promising strategy for optimizing immunotherapy in CRC.

Tumor Microenvironment Dynamics of Triple-Negative Breast Cancer Under Radiation Therapy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of estrogen receptors (ER), progesterone receptors (PR), and HER2 expression. While TNBC is relatively less common, accounting for only 10-15% of initial breast cancer diagnosis, due to its aggressive nature, it carries a worse prognosis in comparison to its hormone receptor-positive counterparts. Despite significant advancements in the screening, diagnosis, and treatment of breast cancer, TNBC remains an important public health burden. Following treatment with chemotherapy, surgery, and radiation, over 40% of TNBC patients experience relapse within 3 years and achieve the least benefit from post-mastectomy radiation. The tumor microenvironment environment (TME) is pivotal in TNBC initiation, progression, immune evasion, treatment resistance, and tumor prognosis. TME is a complex network that consists of immune cells, non-immune cells, and soluble factors located in the region adjacent to the tumor that modulates the therapeutic response differentially between hormone receptor-positive breast cancer and TNBC. While the mechanisms underlying the radiation resistance of TNBC remain unclear, the immunosuppressive TME of TNBC has been implicated in chemotherapeutic resistance. Radiation therapy (RT) is known to alter the TME; however, immune changes elicited by radiation are poorly characterized to date, and whether these immune changes contribute to radiation resistance remains unknown. This review delves into the distinct characteristics of the TNBC TME, explores how RT influences TME dynamics, and examines mechanisms underlying tumor radiosensitization, radioresistance, and immune responses.

High-dose ascorbic acid synergizes with anti-PD1 therapy in non-small cell lung cancer in vitro and in vivo models

Introduction

Immune checkpoint inhibitors(ICIs) targeting programmed cell death protein 1 (PD1) confer significant survival benefits to patients with non-small cell lung cancer (NSCLC). However, there remains a substantial unmet need to identify therapeutic approaches to overcome resistance and provide benefits to these patients. High-dose ascorbic acid (AA) acts synergistically with many standard anticancer treatments. However, little is known about the effect of high-dose AA on improving the efficacy of anti-PD1 inhibitors in NSCLC. This study aimed to elucidate the effects of high-dose AA on anti-PD1 immunotherapy in NSCLC.

Methods

The combined effects of high-dose AA and anti-PD1 were investigated using a coculture model of H460 cells and CD8+ T cells and an LLC1 lung cancer syngeneic mouse model. To investigate the molecular mechanism, tumor tissues from mice were analyzed by comprehensive proteomic profiling using nano-LC-ESI-MS/MS.

Results

Pretreatment with a high dose of AA led to enhanced the sensitivity to the cytotoxicity of CD8+ T cells derived from healthy donor for H460 cells. Additionally, the combination of anti-PD1 and high-dose AA significantly increased CD8+ T cell cytotoxicity in H460 cells. The combination of anti-PD1 and high-dose AA showed dramatic antitumor effects in a syngeneic mouse model of lung cancer by significantly reducing tumor growth and increasing CD8+ T cell-dependent cytotoxicity and macrophage activity. Comprehensive protein analysis confirmed that high-dose AA in anti-PD1-treated tumor tissues enhanced the antitumor effects by regulating various immune-related mechanisms, including the B cell and T cell receptor signaling pathways, Fc gamma R-mediated phagocytosis, and natural killer (NK) cell-mediated cytotoxicity.

Discussion

Our results suggest that high-dose AA may be a promising adjuvant to potentiate the efficacy of anti-PD1 immunotherapy.

Role of Oxidative Stress in the Occurrence, Development, and Treatment of Breast Cancer

Breast cancer is one of the most prevalent cancers worldwide. Recent studies have increasingly emphasized the role of oxidative stress in the initiation and progression of breast cancer. This article reviews how oxidative stress imbalance influences the occurrence and advancement of breast cancer, elucidating the intricate mechanisms through which reactive oxygen species (ROS) operate in this context and their potential therapeutic applications. By highlighting these critical insights, this review aims to enhance our understanding of oxidative stress as a potential target for innovative therapeutic strategies in the management of breast cancer.

PD-1 blockade synergizes with ascorbic acid to restore the activation and anti-viral immune functions of CD8+ T cells in a mouse model of BVDV infection

Bovine viral diarrhea virus (BVDV) can cause typical peripheral lymphopenia and inhibit CD8+ T-cell activation and proliferation. Programmed death-1 (PD-1) blockade has been shown to increase CD8+ T-cell activation during cytopathic (CP) BVDV infection but not non-cytopathic (NCP) BVDV. Notably, ascorbic acid (AA) restores lymphocyte count and activation during SARS-CoV-2 and influenza virus infections and has a synergistic effect with PD-1 blockade to improve antitumor CD8+ T-cell activity. Nevertheless, it remains unclear whether AA exerts an immunomodulatory effect on the activation and proliferation of CD8+ T cells during BVDV infection, especially NCP BVDV infection, or whether PD-1 blockade and AA exert a synergistic effect in regulating CD8+ T cell antiviral activities. In this study, we found that BVDV infection significantly decreased AA levels in serum and CD8+ T cells in a BALB/c mouse model. Interestingly, AA supplementation dramatically downregulated PD-1 expression, restored the activation and proliferation of CD8+ T cells, inhibited viral replication, ameliorated BVDV-induced histological lesions, and upregulated the expression of CD25 and p-ERK. More importantly, we also found a synergistic effect of PD-1 blockade with AA in restoring the activation and proliferation of CD8+ T cells during CP BVDV infection. However, during NCP BVDV infection, a synergistic effect of PD-1 blockade and AA led to the inhibition of viral replication and the promotion of IFN-γ production. Our findings provided new insights into the immunopathological mechanisms of BVDV and the potential value of anti-viral strategies based on AA treatment alone or in combination with PD-1 blockade.

Vitamins, Coenzyme Q10, and Antioxidant Strategies to Improve Oocyte Quality in Women with Gynecological Cancers: A Comprehensive Review

BACKGROUND

Gynecological cancers, including ovarian, cervical, and endometrial cancers, significantly affect both survival and reproductive health in women. Cancer treatments such as chemotherapy and radiotherapy can impair ovarian function, reducing oocyte quality and fertility potential.

OBJECTIVE

This review aims to evaluate how vitamins and antioxidants can enhance fertility and fertility preservation outcomes for women diagnosed with gynecological cancers, particularly in the context of assisted reproductive technologies (ART). Standard treatments for these cancers, including hysterectomy, bilateral salpingo-oophorectomy, radiation, and chemotherapy, often compromise ovarian function and oocyte quality. This review focuses on the potential role of these interventions in improving oocyte quality, thereby supporting successful fertility preservation and ART outcomes.

METHODS

A comprehensive narrative review of the current literature was conducted, examining the effects of vitamins A, C, D3, E, and Coenzyme Q10 on oocyte quality, particularly in the context of oxidative stress and inflammation induced by cancer and its treatments.

RESULTS

The evidence suggests that certain vitamins and antioxidants may mitigate oxidative damage and enhance oocyte quality. Vitamin A supports cumulus-oocyte complex integrity, while vitamins C and E act as potent antioxidants, reducing oxidative stress in ovarian tissues. Vitamin D3 enhances ovarian reserve markers and modulates inflammatory cytokines. Coenzyme Q10 improves mitochondrial function and reduces DNA damage, increasing oocyte viability and fertilization potential.

CONCLUSIONS

The incorporation of specific vitamins and antioxidants into fertility preservation strategies may enhance oocyte quality in women with gynecological cancers. Although the preliminary findings are promising, further research is needed to determine optimal dosages and establish standardized protocols for clinical use.

Effect of perioperative single dose intravenous vitamin C on pain after total hip arthroplasty

INTRODUCTION

Vitamin c can relieve the pain after other diseases, but there are no studies on whether vitamin C can relieve the pain after hip replacement. The purpose of this paper is to study whether vitamin C can relieve the pain after total hip replacement.

PURPOSE

In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients receiving THA at our hospital were randomly assigned to vitamin c or control groups. During the operation, the vitamin C group will receive intravenous injection of 3 g vitamin C, and the control group will receive 3 g placebo. If the patient has postoperative pain, 10 ml subcutaneous injection of morphine will be required as a rescue analgesic. The primary outcome was the amount of postoperative injection of morphine as a rescue analgesic and expression of inflammatory factors, and the secondary outcome was postoperative pain and hip recovery as assessed by visual analog scale (VAS).

RESULTS

The dosage of subcutaneous injection of morphine was significantly reduced in vitamin C group. VAS pain scores at rest and exercise were lower in the vitamin C group 24 h after surgery, and hip motion was better 24 h after surgery, but there was no significant difference between the two groups 24 h after surgery.Nonetheless, the overall changes in morphine usage and VAS scores did not surpass the established minimal clinically important differences (10 mg for morphine consumption; 1.5 at rest and 1.8 during movement for VAS scores).

CONCLUSION

Adding intravenous vitamin c to multimodal analgesia significantly improved morphine consumption, VAS pain score, and functional recovery. However, it is recommended that single intravenous administration of vitamin C during the perioperative period may achieve better pain relief for patients after THA.

QSOX1 facilitates dormant esophageal cancer stem cells to evade immune elimination via PD-L1 upregulation and CD8 T cell exclusion

Dormant cancer stem cells (DCSCs) exhibit characteristics of chemotherapy resistance and immune escape, and they are a crucial source of tumor recurrence and metastasis. However, the underlying mechanisms remain unrevealed. We demonstrate that enriched Gzmk+ CD8+ T cells within the niche of esophageal DCSCs restrict the outgrowth of tumor mass. Nonetheless, DCSCs can escape immune elimination by enhancing PD-L1 signaling, thereby maintaining immune equilibrium. Quiescent fibroblast-derived quiescin sulfhydryl oxidase 1 (QSOX1) promotes the expression of PD-L1 and its own expression in DCSCs by elevating the level of reactive oxygen species. Additionally, high QSOX1 in the dormant tumor niche contributes to the exclusion of CD8+ T cells. Conversely, blocking QSOX1 with Ebselen in combination with anti-PD-1 and chemotherapy can effectively eradicate residual DCSCs by reducing PD-L1 expression and promoting CD8+ T cell infiltration. Clinically, high expression of QSOX1 predicts a poor response to anti-PD-1 treatment in patients with esophageal cancer. Thus, our findings reveal a mechanism whereby QSOX1 promotes PD-L1 upregulation and T cell exclusion, facilitating the immune escape of DCSCs, and QSOX1 inhibition, combined with immunotherapy and chemotherapy, represents a promising therapeutic approach for eliminating DCSCs and preventing recurrence.

Empowering γδ T-cell functionality with vitamin C

Vitamin C (ascorbic acid) is a potent antioxidant and a cofactor for various enzymes including histone demethylases and methylcytosine dioxygenases. Vitamin C also exerts direct cytotoxicity toward selected tumor cells including colorectal carcinoma. Moreover, vitamin C has been shown to impact immune cell differentiation at various levels including maturation and/or functionality of T cells and their progenitors, dendritic cells, B cells, and NK cells. γδ T cells have recently attracted great interest as effector cells for cell-based cancer immunotherapy, due to their HLA-independent recognition of a large variety of tumor cells. While γδ T cells can thus be also applied as an allogeneic off-the-shelf product, it is obvious that the effector function of γδ T cells needs to be optimized to ensure the best possible clinical efficacy. Here we review the immunomodulatory mechanisms of vitamin C with a special focus on how vitamin C enhances the effector function of γδ T cells. We also discuss future directions of how vitamin C can be used in the clinical setting to boost the efficacy of adoptive cell therapies.

Research progress on the role of reactive oxygen species in the initiation, development and treatment of breast cancer

According to international cancer data, breast cancer (BC) is the leading type of cancer in women. Although significant progress has been made in treating BC, metastasis and drug resistance continue to be the primary causes of mortality for many patients. Reactive oxygen species (ROS) play a dual role in vivo: normal levels can maintain the body's normal physiological function; however, high levels of ROS below the toxicity threshold can lead to mtDNA damage, activation of proto-oncogenes, and inhibition of tumor suppressor genes, which are important causes of BC. Differences in the production and regulation of ROS in different BC subtypes have important implications for the development and treatment of BC. ROS can also serve as an important intracellular signal transduction factor by affecting the antioxidant system, activating MAPK and PI3K/AKT, and other signal pathways to regulate cell cycle and change the relationship between cells and the activity of metalloproteinases, which significantly impacts the metastasis of BC. Hypoxia in the BC microenvironment increases ROS production levels, thereby inducing the expression of hypoxia inducible factor-1α (HIF-1α) and forming "ROS- HIF-1α-ROS" cycle that exacerbates BC development. Many anti-BC therapies generate sufficient toxic ROS to promote cancer cell apoptosis, but because the basal level of ROS in BC cells exceeds that of normal cells, this leads to up-regulation of the antioxidant system, drug efflux, and apoptosis inhibition, rendering BC cells resistant to the drug. ROS crosstalks with tumor vessels and stromal cells in the microenvironment, increasing invasiveness and drug resistance in BC.