Jagged1 modulated tumor-associated macrophage differentiation predicts poor prognosis in patients with invasive micropapillary carcinoma of the breast

Notch ligands are biomarkers of anti-TNF response in RA patients

Notch and its ligands play a critical role in rheumatoid arthritis (RA) pathogenesis. Hence, studies were conducted to delineate the functional significance of the Notch pathway in RA synovial tissue (ST) cells and the influence of RA therapies on their expression. Morphological studies reveal that JAG1, DLL4, and Notch1 are highly enriched in RA ST lining and sublining CD68+CD14+ MΦs. JAG1 and DLL4 transcription is jointly upregulated in RA MΦs reprogrammed by TLR4/5 ligation and TNF, whereas Syntenin-1 exposure expands JAG1, DLL4, and Notch1 expression levels in these cells. Single-cell RNA-seq data exhibit that JAG1 and Notch3 are overexpressed on all fibroblast-like synoviocyte (FLS) subpopulations, in parallel, JAG2, DLL1, and Notch1 expression levels are modest on RA FLS and are predominately potentiated by TLR4 ligation. Intriguingly, JAG1, DLL1/4, and Notch1/3 are presented on RA endothelial cells, and their expression is mutually reconfigured by TLR4/5 ligation in the endothelium. Synovial JAG1/JAG2/DLL1 or Notch1/3 transcriptomes were unchanged in patients who received disease-modifying anti-rheumatic drugs (DMARDs) or IL-6R Ab therapy regardless of disease activity score. Uniquely, RA MΦs and endothelial cells rewired by IL-6 displayed DLL4 transcriptional upregulation, and IL-6R antibody treatment disrupted RA ST DLL4 transcription in good responders compared to non-responders or moderate responders. Nevertheless, the JAG1/JAG2/DLL1/DLL4 transcriptome was diminished in anti-TNF good responders with myeloid pathotype and was unaltered in the fibroid pathotype except for DLL4. Taken together, our findings suggest that RA myeloid Notch ligands can serve as markers for anti-TNF responsiveness and trans-activate Notch receptors expressed on RA FLS and/or endothelial cells.

Molecular Pathology of Micropapillary Carcinomas: Is Characteristic Morphology Related to Molecular Mechanisms?

Micropapillary carcinoma is an entity defined histologically in many organs. It is associated with lymph node metastasis and poor prognosis. The main mechanism for its histopathologic appearance is reverse polarization. Although the studies on this subject are limited, carcinomas with micropapillary morphology observed in different organs are examined by immunohistochemical and molecular methods. Differences are shown in these tumors compared with conventional carcinomas regarding the rate of somatic mutations, mRNA and miRNA expressions, and protein expression levels. TP53 , PIK3CA , TERT , KRAS , EGFR , MYC , FGFR1 , BRAF , AKT1 , HER2/ERBB2 , CCND1 , and APC mutations, which genes frequently detected in solid tumors, have also been detected in invasive micropapillary carcinoma (IMPC) in various organs. 6q chromosome loss, DNAH9 , FOXO3 , SEC. 63 , and FMN2 gene mutations associated with cell polarity or cell structure and skeleton have also been detected in IMPCs. Among the proteins that affect cell polarity, RAC1, placoglobin, as well as CLDNs, LIN7A, ZEB1, CLDN1, DLG1, CDH1 (E-cadherin), OCLN, AFDN/AF6, ZEB1, SNAI2, ITGA1 (integrin alpha 1), ITGB1 (integrin beta 1), RHOA, Jagged-1 (JAG1) mRNAs differentially express between IMPC and conventional carcinomas. Prediction of prognosis and targeted therapy may benefit from the understanding of molecular mechanisms of micropapillary morphology. This review describes the molecular pathologic mechanisms underlying the micropapillary changes of cancers in various organs in a cell polarity-related dimension.

Breast Cancer Survival Outcomes and Tumor-Associated Macrophage Markers: A Systematic Review and Meta-Analysis

INTRODUCTION

Tumor-associated macrophages (TAMs) in breast cancer are associated with a poor prognosis. Early studies of TAMs were largely limited to the pan-macrophage marker CD68, however, more recently, an increasing number of studies have used CD163, a marker expressed by alternatively activated M2 macrophages and TAM subsets. We hypothesized that CD163-positive (CD163+) TAMs would be a better predictor of survival outcomes in breast cancer compared to CD68+  TAMs.

METHODS

We performed a systematic literature search of trials (from 1900 to August 2020) reporting overall survival (OS) or progression-free survival (PFS), breast cancer-specific survival (BCSS), TAM phenotype, and density. Thirty-two studies with 8446 patients were included. Meta-analyses were carried out on hazard ratios (HRs) for survival outcomes of breast cancer patients with a high density of TAMs (CD68+ and/or CD163+) compared to a low density of TAMs.

RESULTS

A high density of TAMs (CD68+ and/or CD163+) was associated with decreased OS (HR 1.69, 95% CI 1.37-2.07) and reduced PFS (HR 1.64; 95% CI 1.35-1.99). Subgrouping by CD marker type showed a lower OS for high density of CD163+ TAMs (HR 2.24; 95% CI 1.71-2.92) compared to a high density of CD68+  TAMs (HR 1.5; 95% CI 1.12-2). A high density of TAMs (CD68+  and/or CD163+) in triple-negative breast cancer (TNBC) cases was associated with lower OS (HR 2.81, 95% CI 1.35-5.84).

CONCLUSION

Compared to CD68+  TAMs, a high density of CD163+ TAMs that express a similar phenotype to M2 macrophages are a better predictor of poor survival outcomes in breast cancer.

Tumor-derived Jagged1 promotes cancer progression through immune evasion

Immune checkpoint inhibitor (ICI) therapy is generating remarkable responses in individuals with cancer, but only a small portion of individuals with breast cancer respond well. Here we report that tumor-derived Jagged1 is a key regulator of the tumor immune microenvironment. Jagged1 promotes tumorigenesis in multiple spontaneous mammary tumor models. Through Jagged1-induced Notch activation, tumor cells increase expression and secretion of multiple cytokines to help recruit macrophages into the tumor microenvironment. Educated macrophages crosstalk with tumor-infiltrating T cells to inhibit T cell proliferation and tumoricidal activity. In individuals with triple-negative breast cancer, a high expression level of Jagged1 correlates with increased macrophage infiltration and decreased T cell activity. Co-administration of an ICI PD-1 antibody with a Notch inhibitor significantly inhibits tumor growth in breast cancer models. Our findings establish a distinct signaling cascade by which Jagged1 promotes adaptive immune evasion of tumor cells and provide several possible therapeutic targets.

Role of Notch pathway in effect of mono-2-ethylhexyl phthalate on the proliferation and cell cycle of SH-SY5Y cell

Neuroblastoma (NB) is an estrogen-dependent tumor. Mono-2-ethylhexyl phthalate (MEHP) has an estrogen-like effect. However, the effects of MEHP on the progression of NB are not well illustrated. This study was to clarify the effect of Notch pathway on proliferation and cell cycle of SH-SY5Y cell induced by MEHP. The viability of SH-SY5Y and BE2C cells were detected by CCK8; cell cycle and apoptosis were detected by flow cytometry; the protein expression levels of Notch pathway and cell cycle related proteins were detected by Western-blot. Results show that MEHP exposure can promote cell proliferation and altered the cell cycle. MEHP exposure can up-regulate the expression of C-MYC, Cyclin D1, Bcl-2 and affected the Notch pathway. In conclusion, MEHP exposure can promote NB cell proliferation and affect the cell cycle and apoptosis. Notch pathway plays a critical role in accelerating the cell cycle and inhibiting the apoptosis of SH-SY5Y cells caused by MEHP.

Enhancing Fatty Acid Catabolism of Macrophages Within Aberrant Breast Cancer Tumor Microenvironment Can Re-establish Antitumor Function

Triple-negative breast cancer (TNBC) remains an intractable challenge owing to its aggressive nature and lack of any known therapeutic targets. Macrophages play a crucial role in cancer promotion and poor prognosis within the tumor microenvironment (TME). The phagocytosis checkpoint in macrophages has broader implications for current cancer immunotherapeutic strategies. Here, we demonstrate the modulation in the antitumor activity of macrophages within the aberrant metabolic microenvironment of TNBC by metabolic intervention. The co-culture of macrophages with TNBC cell lines led to a decrease in both their phagocytic function and expression of interleukin (IL)-1β and inducible nitric oxide synthase (iNOS). The transcription of glycolysis and fatty acid (FA) catabolism-related factors was inhibited within the dysregulated tumor metabolic microenvironment. Enhancement of FA catabolism by treatment with the peroxisome proliferator-activated receptor-alpha (PPAR-α) agonist, fenofibrate (FF), could re-establish macrophages to gain their antineoplastic activity by activating the signal transducer and activator of transcription 1 (STAT1) signaling pathway and increasing ATP production by FA oxidation. The combination of fenofibrate and anti-CD47 therapy significantly inhibited tumor growth in a 4T1 tumor-bearing mouse model. In conclusion, the enhancement of FA catabolism of macrophages could re-establish them to resume antitumor activity in the TME. Anti-CD47 therapy combined with fenofibrate may serve as a novel and potential immunotherapeutic approach for the treatment of TNBC.

Linc00514 promotes breast cancer metastasis and M2 polarization of tumor-associated macrophages via Jagged1-mediated notch signaling pathway

BACKGROUND

Tumor-associated macrophages (TAMs) and tumor cells are important components of the tumor microenvironment. M2 polarization of TAMs, which is a major actor in breast cancer malignancy and metastasis, can be induced by breast cancer cells. However, the potential mechanisms of the interaction between breast cancer cells and TAMs remain unclear.

METHODS

The candidate breast cancer-associated long non-coding RNAs (lncRNAs) were analyzed using the GEO database. Functional assays, including MTT assay, Transwell assay, and EdU labeling detection, were performed to investigate the oncogenic role of linc00514 in breast cancer progression. The co-culture and ELISA assays were used to assess the role of linc00514 in macrophage recruitment and M2 polarization. RNA immunoprecipitation, RNA pull-down, and luciferase reporter assays were applied to determine the mechanism of linc00514 in breast cancer metastasis. Mouse xenograft models, mouse pulmonary metastatic models, and mouse primary tumor models were used to assess the role of linc00514 in M2 macrophage polarization and breast cancer tumorigenicity.

RESULTS

Linc00514 was highly expressed in clinical breast cancer tissues and breast cancer cell lines. Overexpression of linc00514 promoted the proliferation and invasion of breast cancer cells and increased xenograft tumor volumes and pulmonary metastatic nodules. Overexpression of linc00514 also increased the percentage of macrophages expressing M2 markers CD206 and CD163. Mechanistically, linc00514 promoted Jagged1 expression in a transcriptional manner by increasing the phosphorylation of a transcription factor STAT3. Subsequently, Jagged1-mediated Notch signaling pathway promoted IL-4 and IL-6 secretions in breast cancer cells and ultimately inducing M2 polarization of macrophages.

CONCLUSION

Linc00514 plays an important role in regulating breast cancer tumorigenicity and M2 macrophage polarization via Jagged1-mediated Notch signaling pathway.

Notch-Inflammation Networks in Regulation of Breast Cancer Progression

Members of the Notch family and chronic inflammation were each separately demonstrated to have prominent malignancy-supporting roles in breast cancer. Recent investigations indicate that bi-directional interactions that exist between these two pathways promote the malignancy phenotype of breast tumor cells and of their tumor microenvironment. In this review article, we demonstrate the importance of Notch-inflammation interplays in malignancy by describing three key networks that act in breast cancer and their impacts on functions that contribute to disease progression: (1) Cross-talks of the Notch pathway with myeloid cells that are important players in cancer-related inflammation, focusing mainly on macrophages; (2) Cross-talks of the Notch pathway with pro-inflammatory factors, exemplified mainly by Notch interactions with interleukin 6 and its downstream pathways (STAT3); (3) Cross-talks of the Notch pathway with typical inflammatory transcription factors, primarily NF-κB. These three networks enhance tumor-promoting functions in different breast tumor subtypes and act in reciprocal manners, whereby Notch family members activate inflammatory elements and vice versa. These characteristics illustrate the fundamental roles played by Notch-inflammation interactions in elevating breast cancer progression and propose that joint targeting of both pathways together may provide more effective and less toxic treatment approaches in this disease.

Notch Signaling Pathway and Endocrine Resistance in Breast Cancer

Nearly 70% of breast cancers express the estrogen receptor (ER) and are hormone-dependent for cell proliferation and survival. Anti-estrogen therapies with aromatase inhibitors (AIs), selective estrogen receptor modulators (SERMs) or selective estrogen receptor down regulators (SERDs) are the standard endocrine therapy approach for ER positive breast cancer patients. However, about 30% of patients receiving endocrine therapy will progress during the therapy or become endocrine resistance eventually. The intrinsic or acquired endocrine resistance has become a major obstacle for endocrine therapy. The mechanism of endocrine resistance is very complicated and recently emerging evidence indicates dysregulation of Notch signaling pathway contributes to endocrine resistance in breast cancer patients. The potential mechanisms include regulation of ER, promotion of cancer stem cell (CSC) phenotype and mesenchymal cell ratio, alteration of the local tumor microenvironment and cell cycle. This review will summarize the latest progress on the investigation of Notch signaling pathway in breast cancer endocrine resistance.

Homologous Recombination Repair Deficiency and the Immune Response in Breast Cancer: A Literature Review

The success of cancer immunotherapy with immune checkpoint blockade (ICB) has demonstrated the importance of targeting a preexisting immune response in a broad spectrum of tumors. This is particularly novel and relevant for less immunogenic tumors, such as breast cancer (BC), where the efficacy of ICB was more evident in the triple-negative (TNBC) subtype, in earlier stages, and in association with chemotherapy. Tumors harboring homologous recombination DNA repair (HRR) deficiency (HRD) are supposed to have a higher number of mutations, hence a higher tumor mutational burden, which could potentially make them more sensitive to immunotherapy. However, the mechanisms involved in ICB sensitivity and patient selection are still yet to be defined in BC: whether the innate system could play a role and how the adaptive immunity could be linked with HRR pathways are the two key points of debate that we will discuss in this article. The aim of this review was to close the loop between what was found in clinical trial results so far, go back to laboratory theory and preclinical results and point out what needs to be clarified from now on.

Tumor-associated macrophages in breast cancer: Innocent bystander or important player?

Tumor-associated macrophages (TAMs) are important tumor-promoting cells in the breast tumor microenvironment. Preclinically TAMs stimulate breast tumor progression, including tumor cell growth, invasion and metastasis. TAMs also induce resistance to multiple types of treatment in breast cancer models. The underlying mechanisms include: induction and maintenance of tumor-promoting phenotype in TAMs, inhibition of CD8+ T cell function, degradation of extracellular matrix, stimulation of angiogenesis and inhibition of phagocytosis. Several studies reported that high TAM infiltration of breast tumors is correlated with a worse patient prognosis. Based on these findings, macrophage-targeted treatment strategies have been developed and are currently being evaluated in clinical breast cancer trials. These strategies include: inhibition of macrophage recruitment, repolarization of TAMs to an antitumor phenotype, and enhancement of macrophage-mediated tumor cell killing or phagocytosis. This review summarizes the functional aspects of TAMs and the rationale and current evidence for TAMs as a therapeutic target in breast cancer.

Notch Signaling in Myeloid Cells as a Regulator of Tumor Immune Responses

Cancer immunotherapy, which stimulates or augments host immune responses to treat malignancies, is the latest development in the rapidly advancing field of cancer immunology. The basic principles of immunotherapies are either to enhance the functions of specific components of the immune system or to neutralize immune-suppressive signals produced by cancer cells or tumor microenvironment cells. When successful, these approaches translate into long-term survival for patients. However, durable responses are only seen in a subset of patients and so far, only in some cancer types. As for other cancer treatments, resistance to immunotherapy can also develop. Numerous research groups are trying to understand why immunotherapy is effective in some patients but not others and to develop strategies to enhance the effectiveness of immunotherapy. The Notch signaling pathway is involved in many aspects of tumor biology, from angiogenesis to cancer stem cell maintenance to tumor immunity. The role of Notch in the development and modulation of the immune response is complex, involving an intricate crosstalk between antigen-presenting cells, T-cell subpopulations, cancer cells, and other components of the tumor microenvironment. Elegant studies have shown that Notch is a central mediator of tumor-induced T-cell anergy and that activation of Notch1 in CD8 T-cells enhances cancer immunotherapy. Tumor-infiltrating myeloid cells, including myeloid-derived suppressor cells, altered dendritic cells, and tumor-associated macrophages along with regulatory T cells, are major obstacles to the development of successful cancer immunotherapies. In this article, we focus on the roles of Notch signaling in modulating tumor-infiltrating myeloid cells and discuss implications for therapeutic strategies that modulate Notch signaling to enhance cancer immunotherapy.

Targeting myeloid cells in the tumor sustaining microenvironment

Myeloid cells are the most abundant cells in the tumor microenvironment (TME). The tumor recruits and modulates endogenous myeloid cells to tumor-associated macrophages (TAM), dendritic cells (DC), myeloid-derived suppressor cells (MDSC) and neutrophils (TAN), to sustain an immunosuppressive environment. Pathologically overexpressed mediators produced by cancer cells like granulocyte-macrophage colony-stimulating- and vascular endothelial growth factor induce myelopoiesis in the bone marrow. Excess of myeloid cells in the blood, periphery and tumor has been associated with tumor burden. In cancer, myeloid cells are kept at an immature state of differentiation to be diverted to an immunosuppressive phenotype. Here, we review human myeloid cells in the TME and the mechanisms for sustaining the hallmarks of cancer. Simultaneously, we provide an introduction into current and novel therapeutic approaches to redirect myeloid cells from a cancer promoting to a rather inflammatory, cancer inhibiting phenotype. In addition, the role of platelets for tumor promotion is discussed.