scholarly journals Tumor-Associated Macrophages in Glioma: Friend or Foe?

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Benjamin C. Kennedy ◽  
Christopher R. Showers ◽  
David E. Anderson ◽  
Lisa Anderson ◽  
Peter Canoll ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Glioma Cell ◽  
Gene Array ◽  
Tumor Development ◽  
Tumor Promotion ◽  
Tumor Associated Macrophages ◽  
And Function ◽  
M1 Type ◽  
Alternatively Activated ◽  
Classically Activated

Tumor-associated macrophages (TAMs) contribute substantially to the tumor mass of gliomas and have been shown to play a major role in the creation of a tumor microenvironment that promotes tumor progression. Shortcomings of attempts at antiglioma immunotherapy may result from a failure to adequately address these effects. Emerging evidence supports an independent categorization of glioma TAMs as alternatively activated M2-type macrophages, in contrast to classically activated proinflammatory M1-type macrophages. These M2-type macrophages exert glioma-supportive effects through reduced anti-tumor functions, increased expression of immunosuppressive mediators, and nonimmune tumor promotion through expression of trophic and invasion-facilitating substances. Much of our work has demonstrated these features of glioma TAMs, and together with the supporting literature will be reviewed here. Additionally, the dynamics of glioma cell-TAM interaction over the course of tumor development remain poorly understood; our efforts to elucidate glioma cell-TAM dynamics are summarized. Finally, the molecular pathways which underlie M2-type TAM polarization and gene expression similarly require further investigation, and may present the most potent targets for immunotherapeutic intervention. Highlighting recent evidence implicating the transcription factor STAT3 in immunosuppressive tumorigenic glioma TAMs, we advocate for gene array-based approaches to identify yet unappreciated expression regulators and effector molecules important to M2-type glioma TAMs polarization and function within the glioma tumor microenvironment.

scholarly journals Embryonic Origin and Subclonal Evolution of Tumor-Associated Macrophages Imply Preventive Care for Cancer

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 903
Author(s):  
Xiao-Mei Zhang ◽  
De-Gao Chen ◽  
Shengwen Calvin Li ◽  
Bo Zhu ◽  
Zhong-Jun Li
Keyword(s):  
Metabolic Regulation ◽  
Transcriptional Profiling ◽  
Tumor Development ◽  
Metabolic Reprogramming ◽  
Cancer Therapies ◽  
Functional Heterogeneity ◽  
Tumor Associated Macrophages ◽  
Metabolic Remodeling ◽  
And Function ◽  
Mapping Models

Macrophages are widely distributed in tissues and function in homeostasis. During cancer development, tumor-associated macrophages (TAMs) dominatingly support disease progression and resistance to therapy by promoting tumor proliferation, angiogenesis, metastasis, and immunosuppression, thereby making TAMs a target for tumor immunotherapy. Here, we started with evidence that TAMs are highly plastic and heterogeneous in phenotype and function in response to microenvironmental cues. We pointed out that efforts to tear off the heterogeneous “camouflage” in TAMs conduce to target de facto protumoral TAMs efficiently. In particular, several fate-mapping models suggest that most tissue-resident macrophages (TRMs) are generated from embryonic progenitors, and new paradigms uncover the ontogeny of TAMs. First, TAMs from embryonic modeling of TRMs and circulating monocytes have distinct transcriptional profiling and function, suggesting that the ontogeny of TAMs is responsible for the functional heterogeneity of TAMs, in addition to microenvironmental cues. Second, metabolic remodeling helps determine the mechanism of phenotypic and functional characteristics in TAMs, including metabolic bias from macrophages’ ontogeny in macrophages’ functional plasticity under physiological and pathological conditions. Both models aim at dissecting the ontogeny-related metabolic regulation in the phenotypic and functional heterogeneity in TAMs. We argue that gleaning from the single-cell transcriptomics on subclonal TAMs’ origins may help understand the classification of TAMs’ population in subclonal evolution and their distinct roles in tumor development. We envision that TAM-subclone-specific metabolic reprogramming may round-up with future cancer therapies.

scholarly journals TFEB is a master regulator of tumor-associated macrophages in breast cancer

2020 ◽  
Vol 8 (1) ◽  
pp. e000543 ◽  
Author(s):  
Yong Li ◽  
Johnie Hodge ◽  
Qing Liu ◽  
Junfeng Wang ◽  
Yuzhen Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Tumor Growth ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Breast Tumor ◽  
Tumor Development ◽  
Tumor Associated Macrophages ◽  
And Function ◽  
The Impact

BackgroundTumor-associated macrophages (TAMs) play key roles in the development of many malignant solid tumors including breast cancer. They are educated in the tumor microenvironment (TME) to promote tumor growth, metastasis, and therapy resistance. However, the phenotype of TAMs is elusive and how to regulate them for therapeutic purpose remains unclear; therefore, TAM-targeting therapies have not yet achieved clinical success. The purposes of this study were to examine the role of transcription factor EB (TFEB) in regulating TAM gene expression and function and to determine if TFEB activation can halt breast tumor development.MethodsMicroarrays were used to analyze the gene expression profile of macrophages (MΦs) in the context of breast cancer and to examine the impact of TFEB overexpression. Cell culture studies were performed to define the mechanisms by which TFEB affects MΦ gene expression and function. Mouse studies were carried out to investigate the impact of MΦ TFEB deficiency or activation on breast tumor growth. Human cancer genome data were analyzed to reveal the prognostic value of TFEB and its regulated genes.ResultsTAM-mimic MΦs display a unique gene expression profile, including significant reduction in TFEB expression. TFEB overexpression favorably modulates TAM gene expression through multiple signaling pathways. Specifically, TFEB upregulates suppressor of cytokine signaling 3 (SOCS3) and peroxisome proliferator-activated receptor γ (PPARγ) expression and autophagy/lysosome activities, inhibits NLRP3 (NLR Family Pyrin Domain Containing 3) inflammasome and hypoxia-inducible factor (HIF)-1α mediated hypoxia response, and thereby suppresses an array of effector molecules in TAMs including arginase 1, interleukin (IL)-10, IL-1β, IL-6 and prostaglandin E2. MΦ-specific TFEB deficiency promotes, while activation of TFEB using the natural disaccharide trehalose halts, breast tumor development by modulating TAMs. Analysis of human patient genome database reveals that expression levels of TFEB, SOCS3 and PPARγ are positive prognostic markers, while HIF-1α is a negative prognostic marker of breast cancer.ConclusionsOur study identifies TFEB as a master regulator of TAMs in breast cancer. TFEB controls TAM gene expression and function through multiple autophagy/lysosome-dependent and independent pathways. Therefore, pharmacological activation of TFEB would be a promising therapeutic approach to improve the efficacy of existing treatment including immune therapies for breast cancer by favorably modulating TAM function and the TME.

scholarly journals Macrophages in Tumor Microenvironments and the Progression of Tumors

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ning-Bo Hao ◽  
Mu-Han Lü ◽  
Ya-Han Fan ◽  
Ya-Ling Cao ◽  
Zhi-Ren Zhang ◽  
...  
Keyword(s):  
Adaptive Immune Response ◽  
M2 Macrophages ◽  
Tumor Associated Macrophages ◽  
M1 Macrophages ◽  
Tumor Microenvironments ◽  
Adaptive Immune ◽  
Immunosuppressive Microenvironment ◽  
Inflammatory Molecules ◽  
Alternatively Activated ◽  
Classically Activated

Macrophages are widely distributed innate immune cells that play indispensable roles in the innate and adaptive immune response to pathogens and in-tissue homeostasis. Macrophages can be activated by a variety of stimuli and polarized to functionally different phenotypes. Two distinct subsets of macrophages have been proposed, including classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages express a series of proinflammatory cytokines, chemokines, and effector molecules, such as IL-12, IL-23, TNF-α, iNOS and MHCI/II. In contrast, M2 macrophages express a wide array of anti-inflammatory molecules, such as IL-10, TGF-β, and arginase1. In most tumors, the infiltrated macrophages are considered to be of the M2 phenotype, which provides an immunosuppressive microenvironment for tumor growth. Furthermore, tumor-associated macrophages secrete many cytokines, chemokines, and proteases, which promote tumor angiogenesis, growth, metastasis, and immunosuppression. Recently, it was also found that tumor-associated macrophages interact with cancer stem cells. This interaction leads to tumorigenesis, metastasis, and drug resistance. So mediating macrophage to resist tumors is considered to be potential therapy.

scholarly journals Differential Polarization of Tumor-Associated Macrophages/Microglia Drives the Aggressiveness of Gliomas

2021 ◽  
Author(s):  
Nai-Wei Yao ◽  
Hsiu-Ting Lin ◽  
Ya-Lin Lin ◽  
Khamushavalli Geeviman ◽  
Fang Liao ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Wistar Rats ◽  
Tumor Development ◽  
C6 Glioma ◽  
Sprague Dawley ◽  
Tumor Associated Macrophages ◽  
Sd Rats ◽  
Glioma Growth

Abstract Background: Glioblastoma is the most aggressive subtype of brain tumors. The major component of tumor microenvironment in glioblastoma is tumor-associated macrophages (TAMs), which are associated with enhanced malignancy of glioblastoma. The polarization of macrophages to the pro-inflammatory M1 or anti-inflammatory M2 subtypes governed by the context of tumor microenvironment may dictate the aggressiveness and outcome of glioblastoma. Given that the immune responses to tumors vary distinctively among individuals due to intrinsic, environmental and genetic factors and that TAMs display a high level of diversity and plasticity, we aimed to examine the effects of differential polarization of TAMs on the glioblastoma development by implanting C6 glioma into brains of Sprague–Dawley (SD) and Wistar rats; these two rats have different genetic background and host microenvironment during tumor development. Methods: Sprague–Dawley (SD) and Wistar rats were implanted with C6 glioma in the brain. The measurement of tumor volumes, tumor morphology and tumor growth in C6 glioma implanted brains were measured by multi-parametric magnetic resonance imaging (MRI). Immunofluorescence staining was performed to analyze tumor angiogenesis and M1 and M2 TAMs in C6 gliomas. Results: By multi-parametric MRI measurement, C6 gliomas developed in the SD rats were characterized with enlarged tumors, accompanied with shorter animal survival. In comparison to the gliomas in Wistar rats, the accelerated tumor growth in SD rats was associated with greater extent of angiogenesis accompanied with higher levels of VEGF/VEGFR2. In support, C6 gliomas in SD rats were filtrated with TAMs characterized with a higher M2/M1 ratio, in contrast to the TAMs of a high M1/M2 ratio in Wistar rats. Attempts were made to shift the M2/M1 balance. Administration of the cytokine IFN-γ that induces M1 TAMs to SD rats greatly suppressed glioma formation, accompanied with a remarkable increase of M1 TAMs. Administration of the cytokines IL-4 plus IL-10 that induces M2 TAMs significantly promoted glioma growth in the Wistar rats, associated with an increase in the M2 TAMs. Conclusions: These results demonstrate an important role of TAMs in glioma pathogenesis and the crucial role of microenvironment in dictating the polarization of TAMs, suggesting that targeting or repolarization of TAMs may serve as an effective intervention for gliomas.

scholarly journals Macrophage Reprogramming and Cancer Therapeutics: Role of iNOS-Derived NO

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3194
Author(s):  
Khosrow Kashfi ◽  
Jasmine Kannikal ◽  
Niharika Nath
Keyword(s):  
Nitric Oxide ◽  
Tumor Microenvironment ◽  
Cancer Therapeutics ◽  
Tumor Promotion ◽  
Cell Types ◽  
Regulatory Pathways ◽  
Inflammatory Phenotype ◽  
Immunosuppressive Tumor Microenvironment ◽  
M1 Type

Nitric oxide and its production by iNOS is an established mechanism critical to tumor promotion or suppression. Macrophages have important roles in immunity, development, and progression of cancer and have a controversial role in pro- and antitumoral effects. The tumor microenvironment consists of tumor-associated macrophages (TAM), among other cell types that influence the fate of the growing tumor. Depending on the microenvironment and various cues, macrophages polarize into a continuum represented by the M1-like pro-inflammatory phenotype or the anti-inflammatory M2-like phenotype; these two are predominant, while there are subsets and intermediates. Manipulating their plasticity through programming or reprogramming of M2-like to M1-like phenotypes presents the opportunity to maximize tumoricidal defenses. The dual role of iNOS-derived NO also influences TAM activity by repolarization to tumoricidal M1-type phenotype. Regulatory pathways and immunomodulation achieve this through miRNA that may inhibit the immunosuppressive tumor microenvironment. This review summarizes the classical physiology of macrophages and polarization, iNOS activities, and evidence towards TAM reprogramming with current information in glioblastoma and melanoma models, and the immunomodulatory and therapeutic options using iNOS or NO-dependent strategies.

Nanomedicine-based cancer immunotherapies developed by reprogramming tumor-associated macrophages

Nanoscale ◽  
2021 ◽  
Author(s):  
Xiaoying Li ◽  
Xiaoming Guo ◽  
Jiabao Ling ◽  
Zheng Tang ◽  
Guanning Huang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Growth Factors ◽  
Tumor Microenvironment ◽  
Blood Vessels ◽  
Immune Cells ◽  
Tumor Development ◽  
Inflammatory Factors ◽  
Tumor Associated Macrophages ◽  
Complex Ecosystem ◽  
Cancer Immunotherapies

Tumor microenvironment is a complex ecosystem composed of tumor extracellular matrix, fibroblasts, blood vessels, and immune cells, promoting tumor development by secreting various growth factors, hydrolase, and inflammatory factors.

Targeting the Tumor Microenvironment by Intervention in Interleukin-1 Biology

2017 ◽  
Vol 23 (32) ◽  
pp. 4893-4905 ◽  
Author(s):  
Elena Voronov ◽  
Ron N. Apte
Keyword(s):  
Tumor Microenvironment ◽  
Cancer Patients ◽  
Tumor Immunity ◽  
Biological Activities ◽  
Interleukin 1 ◽  
Tumor Development ◽  
Tumor Treatment ◽  
Tumor Invasiveness ◽  
First Line Therapy ◽  
Inflammatory Component

The importance of anti-tumor immunity in the outcome of cancer is now unequivocally established and recent achivements in the field have stimulated the development of new immunotherapeutical approaches. In invasive tumors, widespread inflammation promotes invasiveness and concomitantly also inhibits anti-tumor immune responses. We suggest that efficient tumor treatment should target both the malignant cells and the tumor microenvironment. Interleukin-1 (IL-1) is a pro-inflammatory as well as an immunostimulatory cytokine that is abundant in the tumor microenvironment. Manipulation of IL-1 can thus serve as an immunotherapeutical approach to reduce inflammation/immunosuppression and thus enhance anti-tumor immunity. The two major IL-1 agonistic molecules are IL-1α and IL-1β, which bind to the same IL-1 signaling receptor and induce the same array of biological activities. The IL-1 receptor antagonist (IL-Ra) is a physiological inhibitor of IL-1 that binds to its receptor without transmition of activation signals and thus serves as a decoy target. We have demonstrated that IL-1α and IL-1β are different in terms of the producing cells and their compartmentalization and the amount. IL-1α is mainly expressed intracellularly, in the cytosol, in the nucleus or exposed on the cell membrane, however, it is rarely secreted. IL-1β is active only as a secreted molecule that is mainly produced by activated myeloid cells. We have shown different functions of IL-1α and IL-1β in the malignant process. Thus, in its membrane- associated form, IL-1α is mainly immunostimulatory, while IL-1β that is secreted into the tumor microenvironment is mainly pro-inflammatory and promotes tumorigenesis, tumor invasiveness and immunosuppression. These distinct functions of the IL-1 agonistic molecules are mainly manifested in early stages of tumor development and the patterns of their expression dictate the direction of the malignant process. Here, we suggest that IL-1 modulation can serve as an effective mean to tilt the balance between inflammation and immunity in tumor sites, towards the latter. Different agents that neutralize IL-1, mainly the IL-Ra and specific antibodies, exist. They are safe and FDA-approved. The IL-1Ra has been widely and successfully used in patients with Rheumatoid arthritis, autoinflammatory diseases and various other diseases that have an inflammatory component. Here, we provide the rationale and experimental evidence for the use of anti-IL-1 agents in cancer patients, following first line therapy to debulk the major tumor's mass. The considerations and constraints of using anti-IL-1 treatments in cancer are also discussed. We hope that this review will stimulate studies that will fasten the application of IL-1 neutralization at the bedside of cancer patients.

scholarly journals Consumption of Select Dietary Emulsifiers Exacerbates the Development of Spontaneous Intestinal Adenoma

2021 ◽  
Vol 22 (5) ◽  
pp. 2602
Author(s):  
Emilie Viennois ◽  
Benoit Chassaing
Keyword(s):  
Intestinal Inflammation ◽  
Tumor Development ◽  
Low Grade ◽  
Gastrointestinal Cancers ◽  
Cancer Initiation ◽  
And Function ◽  
The Impact ◽  
Chronic Intestinal Inflammation ◽  
Low Grade Inflammation ◽  
Intestinal Adenoma

Inflammation is a well-characterized critical driver of gastrointestinal cancers. Previous findings have shown that intestinal low-grade inflammation can be promoted by the consumption of select dietary emulsifiers, ubiquitous component of processed foods which alter the composition and function of the gut microbiota. Using a model of colitis-associated cancer, we previously reported that consumption of the dietary emulsifiers carboxymethylcellulose or polysorbate-80 exacerbated colonic tumor development. Here, we investigate the impact of dietary emulsifiers consumption on cancer initiation and progression in a genetical model of intestinal adenomas. In APCmin mice, we observed that dietary emulsifiers consumption enhanced small-intestine tumor development in a way that appeared to be independent of chronic intestinal inflammation but rather associated with emulsifiers’ impact on the proliferative status of the intestinal epithelium as well as on intestinal microbiota composition in both male and female mice. Overall, our findings further support the hypothesis that emulsifier consumption may be a new modifiable risk factor for colorectal cancer (CRC) and that alterations in host–microbiota interactions can favor gastrointestinal carcinogenesis in individuals with a genetical predisposition to such disorders.

scholarly journals Tumor-associated macrophages: potential therapeutic strategies and future prospects in cancer

2021 ◽  
Vol 9 (1) ◽  
pp. e001341
Author(s):  
Chunxiao Li ◽  
Xiaofei Xu ◽  
Shuhua Wei ◽  
Ping Jiang ◽  
Lixiang Xue ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Poor Prognosis ◽  
Tumor Immunotherapy ◽  
Therapeutic Strategies ◽  
Preclinical Studies ◽  
Future Prospects ◽  
Tumor Associated Macrophages

Macrophages are the most important phagocytes in vivo. However, the tumor microenvironment can affect the function and polarization of macrophages and form tumor-associated macrophages (TAMs). Usually, the abundance of TAMs in tumors is closely associated with poor prognosis. Preclinical studies have identified important pathways regulating the infiltration and polarization of TAMs during tumor progression. Furthermore, potential therapeutic strategies targeting TAMs in tumors have been studied, including inhibition of macrophage recruitment to tumors, functional repolarization of TAMs toward an antitumor phenotype, and other therapeutic strategies that elicit macrophage-mediated extracellular phagocytosis and intracellular destruction of cancer cells. Therefore, with the increasing impact of tumor immunotherapy, new antitumor strategies to target TAMs are now being discussed.

scholarly journals Distinct uptake, amplification, and release of SARS-CoV-2 by M1 and M2 alveolar macrophages

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiadi Lv ◽  
Zhenfeng Wang ◽  
Yajin Qu ◽  
Hua Zhu ◽  
Qiangqiang Zhu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Mouse Model ◽  
Alveolar Macrophages ◽  
Transgenic Mouse Model ◽  
Lysosomal Ph ◽  
Viral Spread ◽  
Lysosomal System ◽  
Endosomal Ph ◽  
Alternatively Activated ◽  
Classically Activated

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the alveoli, where abundant alveolar macrophages (AMs) reside. How AMs respond to SARS-CoV-2 invasion remains elusive. Here, we show that classically activated M1 AMs facilitate viral spread; however, alternatively activated M2 AMs limit the spread. M1 AMs utilize cellular softness to efficiently take up SARS-CoV-2. Subsequently, the invaded viruses take over the endo-lysosomal system to escape. M1 AMs have a lower endosomal pH, favoring membrane fusion and allowing the entry of viral RNA from the endosomes into the cytoplasm, where the virus achieves replication and is packaged to be released. In contrast, M2 AMs have a higher endosomal pH but a lower lysosomal pH, thus delivering the virus to lysosomes for degradation. In hACE2 transgenic mouse model, M1 AMs are found to facilitate SARS-CoV-2 infection of the lungs. These findings provide insights into the complex roles of AMs during SARS-CoV-2 infection, along with potential therapeutic targets.

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