Neutrophils in triple-negative breast cancer: an underestimated player with increasingly recognized importance

Identification of a biomarker to predict doxorubicin/cisplatin chemotherapy efficacy in osteosarcoma patients using primary, recurrent and metastatic specimens

BACKGROUND

Doxorubicin and cisplatin are both first-line chemotherapeutics for osteosarcoma (OS) treatment. However, the efficacy of doxorubicin/cisplatin chemotherapy varies considerably. Thus, identifying an efficient diagnostic biomarker to distinguish patients with good and poor responses to doxorubicin/cisplatin chemotherapy is of paramount importance.

METHODS

To predict the efficacy of doxorubicin/cisplatin chemotherapy, we analyzed the differentially expressed proteins in 37 resected OS samples, which were categorized into the primary group (PG), the recurrent group (RG) and the metastatic group (MG). The characteristics of the enriched differentially expressed proteins were assessed via GO and KEGG analyses. Protein‒protein interactions were identified to determine the relationships among the differentially expressed proteins. Receiver operating characteristic (ROC) curve analyses were performed to explore the clinical significance of the differentially expressed proteins. Parallel reaction monitoring (PRM) was used to validate the candidate proteins. Immunohistochemical (IHC) staining was performed to confirm the expression of cathepsin (CTSG) in patients with good and poor response to doxorubicin/cisplatin.

RESULTS

A total of 9458 proteins were identified and quantified, among which 143 and 208 exhibited significant changes (|log2FC|>1, p < 0.05) in the RG and MG compared with the PG, respectively. GO and KEGG enrichment led to the identification of neutrophil extracellular traps (NETs). ROC curve analyses revealed 74 and 86 proteins with areas under the curve greater than 0.7 in the RG and MG, respectively. PRM validation revealed the statistical significance of CTSG, which is involved in NET formation, at the protein level in both the RG and MG. IHC staining of another cohort revealed that CTSG was prominently upregulated in the poor response group after treatment with doxorubicin/cisplatin.

CONCLUSION

CTSG and its associated NETs are potential biomarkers with which the efficacy of doxorubicin/cisplatin chemotherapy could be predicted in OS patients.

CTC-neutrophil interaction: A key driver and therapeutic target of cancer metastasis

Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor and enter the bloodstream, where they can seed new metastatic lesions in distant organs. CTCs are often associated with white blood cells (WBCs), especially neutrophils, the most abundant and versatile immune cells in the blood. Neutrophils can interact with CTCs through various mechanisms, such as cell-cell adhesion, cytokine secretion, protease release, and neutrophil extracellular traps (NETs) formation. These interactions can promote the survival, proliferation, invasion, and extravasation of CTCs, as well as modulate the pre-metastatic niche and the tumor microenvironment. Therefore, inhibiting CTC-neutrophils interaction could be a potential strategy to reduce tumor metastasis and improve the prognosis of cancer patients. In this review, we summarize the current literature on CTC-neutrophils interaction' role in tumor metastasis and discuss the possible therapeutic approaches to target this interaction.

How neutrophils shape the immune response of triple-negative breast cancer: Novel therapeutic strategies targeting neutrophil extracellular traps

Triple-negative breast cancer (TNBC) is labeled as an aggressive type of breast cancer and still has limited therapeutic targets despite the advanced development of cancer therapy. Neutrophils, representing the conventional inflammatory response, significantly influence the malignant phenotype of tumors, supported by abundant evidence. As a vital function of neutrophils, NETs are the extracellular fibrous networks including the depolymerized chromatin DNA frames with several antimicrobial proteins. They are produced by activated neutrophils and are involved in host defence or immunological reactions. This review focuses more on the interactions between neutrophils and TNBC, focusing on how neutrophils modulate the immune response within the tumor milieu. Specifically, we delve into the role of NETs, which are involved in promoting tumor growth and metastasis, inhibiting anti-tumor immunity, and promoting tumor-associated thrombosis. Furthermore, we discuss recent advancements in therapeutic strategies aimed at targeting NETs to enhance the efficacy of TNBC treatment. The advances in the knowledge of the dynamics between neutrophils and TNBC may lead to the opportunity to devise new immunotherapeutic strategies targeted to fight this hostile type of breast cancer.

Engineered Cell Membrane-Coated Nanoparticles: New Strategies in Glioma Targeted Therapy and Immune Modulation

Gliomas, the most prevalent primary brain tumors, pose considerable challenges due to their heterogeneity, intricate tumor microenvironment (TME), and blood-brain barrier (BBB), which restrict the effectiveness of traditional treatments like surgery and chemotherapy. This review provides an overview of engineered cell membrane technologies in glioma therapy, with a specific emphasis on targeted drug delivery and modulation of the immune microenvironment. This study investigates the progress in engineered cell membranes, encompassing physical, chemical, and genetic alterations, to improve drug delivery across the BBB and effectively target gliomas. The examination focuses on the interaction of engineered cell membrane-coated nanoparticles (ECM-NPs) with the TME in gliomas, emphasizing their potential to modulate glioma cell behavior and TME to enhance therapeutic efficacy. The review further explores the involvement of ECM-NPs in immunomodulation techniques, highlighting their impact on immune reactions. While facing obstacles related to membrane stability and manufacturing scalability, the review outlines forthcoming research directions focused on enhancing membrane performance. This review underscores the promise of ECM-NPs in surpassing conventional therapeutic constraints, proposing novel approaches for efficacious glioma treatment.

Breast Cancer Immune Landscape: Interplay Between Systemic and Local Immunity

Breast cancer (BC) is one of the most common malignancies in women worldwide. Numerous studies in immuno-oncology and successful trials of immunotherapy have demonstrated the causal role of the immune system in cancer pathogenesis. The interaction between the tumor and the immune system is known to have a dual nature. Despite cytotoxic lymphocyte activity against transformed cells, a tumor can escape immune surveillance and leverage chronic inflammation to maintain its own development. Research on antitumor immunity primarily focuses on the role of the tumor microenvironment, whereas the systemic immune response beyond the tumor site is described less thoroughly. Here, a comprehensive review of the formation of the immune profile in breast cancer patients is offered. The interplay between systemic and local immune reactions as self-sustaining mechanism of tumor progression is described and the functional activity of the main cell populations related to innate and adaptive immunity is discussed. Additionally, the interaction between different functional levels of the immune system and their contribution to the development of the pro- or anti-tumor immune response in BC is highlighted. The presented data can potentially inform the development of new immunotherapy strategies in the treatment of patients with BC.

Mechanisms underlying neutrophils adhesion to triple-negative breast cancer cells via CD11b-ICAM1 in promoting breast cancer progression

BACKGROUND

Triple-negative breast cancer (TNBC) is recognized as the most aggressive and immunologically infiltrated subtype of breast cancer. A high circulating neutrophil-to-lymphocyte ratio (NLR) is strongly linked to a poor prognosis among patients with breast cancer, emphasizing the critical role of neutrophils. Although the involvement of neutrophils in tumor metastasis is well documented, their interactions with primary tumors and tumor cells are not yet fully understood.

METHODS

Clinical data were analyzed to investigate the role of neutrophils in breast cancer. In vivo mouse model and in vitro co-culture system were used for mechanism researches. Blocking experiments were further performed to identify therapeutic agents against TNBC.

RESULTS

TNBC cells secreted GM-CSF to sustain the survival of mature neutrophils and upregulated CD11b expression. Through CD11b, neutrophils specifically binded to ICAM1 on TNBC cells, facilitating adhesion. Transcriptomic sequencing combined with human and murine functional experiments revealed that neutrophils, through direct CD11b-ICAM1 interactions, activated the MAPK signaling pathway in TNBC cells, thereby enhancing tumor cell invasion and migration. Atorvastatin effectively inhibited ICAM1 expression in tumor cells, and tumor cells with ICAM1 knockout or treated with atorvastatin were unresponsive to neutrophil activation. The MAPK pathway and MMP9 expression were significantly inhibited in the tumor tissues of TNBC patients treated with atorvastatin.

CONCLUSIONS

Targeting CD11b-ICAM1 with atorvastatin represented a potential clinical approach to reduce the malignant characteristics of TNBC.

A β-Carboline Derivate PAD4 Inhibitor Reshapes Neutrophil Phenotype and Improves the Tumor Immune Microenvironment against Triple-Negative Breast Cancer

Triple-negative breast cancer is a highly aggressive and heterogeneous breast cancer subtype characterized by early metastasis, poor prognosis, and high recurrence. Targeting histone citrullination-mediated chromatin dysregulation to induce epigenetic alterations shows great promise in TNBC therapy. We report the synthesis, optimization, and evaluation of a novel series of β-carboline-derived peptidyl arginine deiminase 4 inhibitors that exhibited potent inhibition of TNBC cell proliferation. The most outstanding PAD4 inhibitor, compound 28, hindered the PAD4-H3cit-NET signaling pathway and inhibited the growth of solid tumors and pulmonary metastatic nodules in the 4T1 in situ mouse model. Furthermore, 28 improved the tumor immune microenvironment by reshaping neutrophil phenotype, upregulating the proportions of dendritic cells and M1 macrophages, and reducing the amount of myeloid-derived suppressor cells. In conclusion, our work offered 28 as an efficacious PAD4 inhibitor that exerts a combination of conventional chemotherapy and immune-boosting effects, which represents a potential therapy strategy for TNBC.

Tumor-Intrinsic Enhancer of Zeste Homolog 2 Controls Immune Cell Infiltration, Tumor Growth, and Lung Metastasis in a Triple-Negative Breast Cancer Model

Triple-negative breast cancer (TNBC) is an aggressive and highly metastatic type of tumor. TNBC is often enriched in tumor-infiltrating neutrophils (TINs), which support cancer growth in part by counteracting tumor-infiltrating lymphocytes (TILs). Prior studies identified the enhancer of zeste homolog 2 (EZH2) as a pro-tumor methyltransferase in primary and metastatic TNBCs. We hypothesized that EZH2 inhibition in TNBC cells per se would exert antitumor activity by altering the tumor immune microenvironment. To test this hypothesis, we used CRISPR to generate EZH2 gene knockout (KO) and overexpressing (OE) lines from parent (wild-type-WT) 4T1 cells, an established murine TNBC model, resulting in EZH2 protein KO and OE, respectively. In vitro, EZH2 KO and OE cells showed early, transient changes in replicative capacity and invasiveness, and marked changes in surface marker profile and cytokine/chemokine secretion compared to WT cells. In vivo, EZH2 KO cells showed significantly reduced primary tumor growth and a 10-fold decrease in lung metastasis compared to WT cells, while EZH2 OE cells were unchanged. Compared to WT tumors, TIN:TIL ratios were greatly reduced in EZH2 KO tumors but unchanged in EZH2 OE tumors. Thus, EZH2 is key to 4T1 aggressiveness as its tumor-intrinsic knockout alters their in vitro secretome and in vivo primary tumor growth, TIN/TIL poise, and metastasis.

Neutrophil Extracellular Traps in Breast Cancer: Roles in Metastasis and Beyond

Despite advances in the treatment of breast cancer, the disease continues to exhibit high global morbidity and mortality. The importance of neutrophils in cancer development has been increasingly recognized. Neutrophil extracellular traps (NETs) are web-like structures released into the extracellular space by activated neutrophils, serving as a potential antimicrobial mechanism for capturing and eliminating microorganisms. The roles played by NETs in cancer development have been a subject of intense research in the last decade. In breast cancer, current evidence suggests that NETs are involved in various stages of cancer development, particularly during metastasis. In this review, we try to provide an updated overview of the roles played by NETs in breast cancer metastasis. These include: 1) facilitating systemic dissemination of cancer cells; 2) promoting cancer-associated inflammation; 3) facilitating cancer-associated thrombosis; 4) facilitating pre-metastatic niche formation; and 5) awakening dormant cancer cells. The translational implications of NETs in breast cancer treatment are also discussed. Understanding the relationship between NETs and breast cancer metastasis is expected to provide important insights for developing new therapeutic strategies for breast cancer patients.

Induced electric fields inhibit breast cancer growth and metastasis by modulating the immune tumor microenvironment

Despite tremendous advances in oncology, metastatic triple-negative breast cancer remains difficult to treat and manage with established therapies. Here, we show in mice with orthotopic triple-negative breast tumors that alternating (100 kHz), and low intensity (<1 mV/cm) induced electric fields (iEFs) significantly reduced primary tumor growth and distant lung metastases. Non-contact iEF treatment can be delivered safely and non-invasively in vivo via a hollow, rectangular solenoid coil. We discovered that iEF treatment enhances anti-tumor immune responses at both the primary breast and secondary lung sites. In addition, iEF reduces immunosuppressive TME by reducing effector CD8+ T cell exhaustion and the infiltration of immunosuppressive immune cells. Furthermore, iEF treatment reduced lung metastasis by increasing CD8+ T cells and reducing immunosuppressive Gr1+ neutrophils in the lung microenvironment. We also observed that iEFs reduced the metastatic potential of cancer cells by inhibiting epithelial-to-mesenchymal transition. By introducing a non-invasive and non-toxic electrotherapeutic for inhibiting metastatic outgrowth and enhancing anti-tumor immune response in vivo, treatment with iEF technology could add to a paradigm-shifting strategy for cancer therapy.

Integrative spatial omics reveals distinct tumor-promoting multicellular niches and immunosuppressive mechanisms in African American and European American patients with TNBC

Racial disparities in triple-negative breast cancer (TNBC) outcomes have been reported. However, the biological mechanisms underlying these disparities remain unclear. We integrated imaging mass cytometry and spatial transcriptomics, to characterize the tumor microenvironment (TME) of African American (AA) and European American (EA) patients with TNBC. The TME in AA patients was characterized by interactions between endothelial cells, macrophages, and mesenchymal-like cells, which were associated with poor patient survival. In contrast, the EA TNBC-associated niche is enriched in T-cells and neutrophils suggestive of an exhaustion and suppression of otherwise active T cell responses. Ligand-receptor and pathway analyses of race-associated niches found AA TNBC to be immune cold and hence immunotherapy resistant tumors, and EA TNBC as inflamed tumors that evolved a distinctive immunosuppressive mechanism. Our study revealed the presence of racially distinct tumor-promoting and immunosuppressive microenvironments in AA and EA patients with TNBC, which may explain the poor clinical outcomes.

Construction and multicohort validation of a colon cancer prognostic risk score system based on big data of neutrophil-associated differentially expressed genes

Objective: To investigate the role of neutrophils in colon cancer progression. Methods: Genetic data from 1,273 patients with colon cancer were procured from public databases and categorized based on genes linked to neutrophils through an unsupervised clustering approach. Through univariate Cox regression analysis, differentially expressed genes (DEGs) influencing overall survival (OS) were identified, forming the basis for establishing a prognostic risk score (PRS) system specific to colon cancer. Additionally, the correlation between PRS and patient prognosis, immune cell infiltration, and intratumoral gene mutations were analyzed. Validation of PRS as an indicator for "pan-tumor" immunotherapy was conducted using four distinct immunotherapy cohorts. Results: The research identified two distinct subtypes of colon cancer, namely Cluster A and B, with patients in Cluster B demonstrating remarkably superior prognoses over those in Cluster A. A total of 17 genes affecting OS were screened based on 109 DEGs between the two cluster for constructing the PRS system. Notably, individuals classified under the high-PRS group (PRShigh) exhibited poorer prognoses, significantly linked with immune cell infiltration, an immunosuppressive tumor microenvironment, and increased genomic mutations. Remarkably, analysis of immunotherapy cohorts indicated that patients with PRShigh exhibited enhanced clinical responses, a higher rate of progression-free events, and improved overall survival post-immunotherapy. The PRS system, developed based on tumor typing utilizing neutrophil-associated genes, exhibited a strong correlation with prognostic elements in colon cancer and emerged as a vital predictor of "pan-tumor" immunotherapy efficacy. Conclusions: PRS serves as a prognostic model for patients with colon cancer and holds the potential to act as a "pan-tumor" universal marker for assessing immunotherapy efficacy across different tumor types. The study findings lay a foundation for novel antitumor strategies centered on neutrophil-focused approaches.

Identification and validation of neutrophils-related subtypes and prognosis model in triple negative breast cancer

BACKGROUND

Neutrophils are considered to be crucial players in the initiation and progression of cancer. However, the complex relationship between neutrophils and cancer prognosis remains elusive, mainly due to the significant plasticity and diversity exhibited by these immune cells.

METHODS

As part of our thorough investigation, we examined 38 Neutrophils-Related Genes (NRGs) and the associated copy number variations (CNV), somatic mutations, and gene expression patterns in relation to triple negative breast cancer (TNBC). The interactions between these genes, their biological roles, and their possible prognostic significance were then examined. With the NRGs as our basis, we applied Lasso and Cox regression analyses to create a predictive model for overall survival (OS). Furthermore, TNBC tissue and a public database were used to assess changes in MYO1D expression (MYO1D is characterized as a member of the myosin-I family, a group of motor proteins based on actin), its connection to neutrophil infiltration, and the clinical importance of MYO1D in TNBC.

RESULTS

Four neutrophil-related genes were included in the development of a prognostic model based on neutrophils. The model was further shown to be an independent predicted factor for overall survival by multivariate Cox regression analysis. According to this study, neutrophil subtype B as well as gene subtype B, were associated with activated cancer immunity and poor prognosis of TNBC patients. Furthermore, considering that poor OS was linked to increased MYO1D expression, MYO1D was increased in TNBC tissues and associated with neutrophil infiltration. In vitro experiments also confirmed that MYO1D facilitates breast cancer invasion and metastasis.

CONCLUSION

Based on the degree of gene expression linked to neutrophils, a unique prognostic model was created. MYO1D could be a potential prognostic biomarker in TNBC patients and also a prospective target for therapy.

Potential involvement of neutrophils on exercise effects in breast cancer malignancy

PURPOSE

This review aimed to comprehensively explore and elucidate multifaceted neutrophils in breast cancer, particularly in the context of physical activity. Neutrophils play a critical role in the tumor microenvironment and systemic immune response, despite their short half-life and terminal differentiation. Through a thorough review of research related to changes in immunity in breast cancer during exercise, this review aims to provide comprehensive insights into immunological changes, especially focusing on neutrophils. Recognizing that much of the existing research has predominantly focused on T cells and nature killer (NK) cells, our review seeks to shift the spotlight toward understanding how exercise affects neutrophils, a less-explored but critical immune response component in breast cancer.

METHODS

This study involved an extensive review of the literature (from 2000 to 2023) using the PubMed, Science Direct, and Google Scholar databases. The keywords chosen for the searches were "immune cells and exercise," "exercise and breast cancer," "tumor microenvironment and neutrophils," and "neutrophils and exercise and breast cancers."

RESULTS

Neutrophils in the tumor microenvironment can exhibit distinct phenotypes and functions. These differences have yielded conflicting results regarding tumor progression. Exercise plays a positive role in breast cancer and alters the immune system. Physical activity can quantitatively and functionally regulate neutrophils under various conditions such as metabolic disruption or senescence.

CONCLUSION

This short communication outlines exercise-induced neutrophil diversification and its role in breast cancer progression, both within and systemically within the tumor microenvironment. Exercise may provide benefits through the potential neutrophil involvement in breast cancer.