scholarly journals The role of the tumor microbe microenvironment in the tumor immune microenvironment: bystander, activator, or inhibitor?

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jiayao Ma ◽  
Lingjuan Huang ◽  
Die Hu ◽  
Shan Zeng ◽  
Ying Han ◽  
...  
Keyword(s):  
Immune Cells ◽  
Tumor Antigens ◽  
Checkpoint Inhibitors ◽  
Immune Microenvironment ◽  
Tumor Immune Microenvironment ◽  
Underlying Mechanisms ◽  
First Time ◽  
Activator Inhibitor ◽  
Stimulation Of

AbstractThe efficacy of cancer immunotherapy largely depends on the tumor microenvironment, especially the tumor immune microenvironment. Emerging studies have claimed that microbes reside within tumor cells and immune cells, suggesting that these microbes can impact the state of the tumor immune microenvironment. For the first time, this review delineates the landscape of intra-tumoral microbes and their products, herein defined as the tumor microbe microenvironment. The role of the tumor microbe microenvironment in the tumor immune microenvironment is multifaceted: either as an immune activator, inhibitor, or bystander. The underlying mechanisms include: (I) the presentation of microbial antigens by cancer cells and immune cells, (II) microbial antigens mimicry shared with tumor antigens, (III) microbe-induced immunogenic cell death, (IV) microbial adjuvanticity mediated by pattern recognition receptors, (V) microbe-derived metabolites, and (VI) microbial stimulation of inhibitory checkpoints. The review further suggests the use of potential modulation strategies of the tumor microbe microenvironment to enhance the efficacy and reduce the adverse effects of checkpoint inhibitors. Lastly, the review highlights some critical questions awaiting to be answered in this field and provides possible solutions. Overall, the tumor microbe microenvironment modulates the tumor immune microenvironment, making it a potential target for improving immunotherapy. It is a novel field facing major challenges and deserves further exploration.

scholarly journals Tumor Immune Microenvironment and Its Related miRNAs in Tumor Progression

2021 ◽  
Vol 12 ◽  
Author(s):  
Yingying Xing ◽  
Guojing Ruan ◽  
Haiwei Ni ◽  
Hai Qin ◽  
Simiao Chen ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Progression ◽  
Tumor Cells ◽  
Immune Cells ◽  
Suppressor Cells ◽  
Immune Microenvironment ◽  
Non Coding Rna ◽  
Tumor Immune Microenvironment ◽  
Downstream Gene Expression

MiRNA is a type of small non-coding RNA, by regulating downstream gene expression that affects the progression of multiple diseases, especially cancer. MiRNA can participate in the biological processes of tumor, including proliferation, invasion and escape, and exhibit tumor enhancement or inhibition. The tumor immune microenvironment contains numerous immune cells. These cells include lymphocytes with tumor suppressor effects such as CD8+ T cells and natural killer cells, as well as some tumor-promoting cells with immunosuppressive functions, such as regulatory T cells and myeloid-derived suppressor cells. MiRNA can affect the tumor immune microenvironment by regulating the function of immune cells, which in turn modulates the progression of tumor cells. Investigating the role of miRNA in regulating the tumor immune microenvironment will help elucidate the specific mechanisms of interaction between immune cells and tumor cells, and may facilitate the use of miRNA as a predictor of immune disorders in tumor progression. This review summarizes the multifarious roles of miRNA in tumor progression through regulation of the tumor immune microenvironment, and provides guidance for the development of miRNA drugs to treat tumors and for the use of miRNA as an auxiliary means in tumor immunotherapy.

scholarly journals Tumor-Associated Macrophages: Critical Players in Drug Resistance of Breast Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Maoyu Xiao ◽  
Jun He ◽  
Liyang Yin ◽  
Xiguan Chen ◽  
Xuyu Zu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Therapeutic Strategies ◽  
Tumor Associated Macrophages ◽  
Immune Microenvironment ◽  
Tumor Immune Microenvironment ◽  
Potential Possibility ◽  
Underlying Mechanisms ◽  
Novel Therapeutic Strategies

Drug resistance is one of the most critical challenges in breast cancer (BC) treatment. The occurrence and development of drug resistance are closely related to the tumor immune microenvironment (TIME). Tumor-associated macrophages (TAMs), the most important immune cells in TIME, are essential for drug resistance in BC treatment. In this article, we summarize the effects of TAMs on the resistance of various drugs in endocrine therapy, chemotherapy, targeted therapy, and immunotherapy, and their underlying mechanisms. Based on the current overview of the key role of TAMs in drug resistance, we discuss the potential possibility for targeting TAMs to reduce drug resistance in BC treatment, By inhibiting the recruitment of TAMs, depleting the number of TAMs, regulating the polarization of TAMs and enhancing the phagocytosis of TAMs. Evidences in our review support it is important to develop novel therapeutic strategies to target TAMs in BC to overcome the treatment of resistance.

scholarly journals Role of Epigenetic Regulation in Plasticity of Tumor Immune Microenvironment

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunkai Yang ◽  
Yan Wang
Keyword(s):  
Immune Cells ◽  
Noncoding Rna ◽  
Immune Escape ◽  
Genetic Regulation ◽  
Epigenetic Alterations ◽  
Immune Microenvironment ◽  
Post Translational Modifications ◽  
Human Genes ◽  
Tumor Immune Microenvironment

The tumor immune microenvironment (TIME), an immunosuppressive niche, plays a pivotal role in contributing to the development, progression, and immune escape of various types of cancer. Compelling evidence highlights the feasibility of cancer therapy targeting the plasticity of TIME as a strategy to retrain the immunosuppressive immune cells, including innate immune cells and T cells. Epigenetic alterations, such as DNA methylation, histone post-translational modifications, and noncoding RNA-mediated regulation, regulate the expression of many human genes and have been reported to be accurate in the reprogramming of TIME according to vast majority of published results. Recently, mounting evidence has shown that the gut microbiome can also influence the colorectal cancer and even extraintestinal tumors via metabolites or microbiota-derived molecules. A tumor is a kind of heterogeneous disease with specificity in time and space, which is not only dependent on genetic regulation, but also regulated by epigenetics. This review summarizes the reprogramming of immune cells by epigenetic modifications in TIME and surveys the recent progress in epigenetic-based cancer clinical therapeutic approaches. We also discuss the ongoing studies and future areas of research that benefits to cancer eradication.

scholarly journals Pivotal Role of STAT3 in Shaping Glioblastoma Immune Microenvironment

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1398 ◽  
Author(s):  
Christina Piperi ◽  
Kostas A. Papavassiliou ◽  
Athanasios G. Papavassiliou
Keyword(s):  
Immune Cells ◽  
Therapy Resistance ◽  
Pivotal Role ◽  
Immune Microenvironment ◽  
Dismal Prognosis ◽  
Selective Targeting ◽  
Tumor Immune Microenvironment ◽  
Inflammatory Phenotypes ◽  
Transcription 3

Glioblastoma belongs to the most malignant intracranial tumors characterized by indispensable growth and aggressiveness that highly associates with dismal prognosis and therapy resistance. Tumor heterogeneity that often challenges therapeutic schemes is largely attributed to the complex interaction of neoplastic cells with tumor microenvironment (TME). Soluble immunoregulatory molecules secreted by glioma cells attract astrocytes, circulating stem cells and a range of immune cells to TME, inducing a local production of cytokines, chemokines and growth factors that reprogram immune cells to inflammatory phenotypes and manipulate host’s immune response in favor of cancer growth and metastasis. Accumulating evidence indicates that these tolerogenic properties are highly regulated by the constitutive and persistent activation of the oncogenic signal transducer and activator of transcription 3 (STAT3) protein, which impairs anti-tumor immunity and enhances tumor progression. Herein, we discuss current experimental and clinical evidence that highlights the pivotal role of STAT3 in glioma tumorigenesis and particularly in shaping tumor immune microenvironment in an effort to justify the high need of selective targeting for glioma immunotherapy.

scholarly journals The Role of the Tumor Microenvironment and Treatment Strategies in Colorectal Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaping Chen ◽  
Xiao Zheng ◽  
Changping Wu
Keyword(s):  
Colorectal Cancer ◽  
Checkpoint Inhibitors ◽  
Treatment Strategies ◽  
Research Progress ◽  
Immune Microenvironment ◽  
Appropriate Treatment ◽  
Tumor Immune Microenvironment ◽  
The Relationship ◽  
Selection Of

Colorectal cancer (CRC) has the second highest mortality rate among all cancers worldwide. Surgery, chemotherapy, radiotherapy, molecular targeting and other treatment methods have significantly prolonged the survival of patients with CRC. Recently, the emergence of tumor immunotherapy represented by immune checkpoint inhibitors (ICIs) has brought new immunotherapy options for the treatment of advanced CRC. As the efficacy of ICIs is closely related to the tumor immune microenvironment (TME), it is necessary to clarify the relationship between the immune microenvironment of CRC and the efficacy of immunotherapy to ensure that the appropriate drugs are selected. We herein review the latest research progress in the immune microenvironment and strategies related to immunotherapy for CRC. We hope that this review helps in the selection of appropriate treatment strategies for CRC patients.

scholarly journals Differential Role of PD-1 Expressed by Various Immune and Tumor Cells in the Tumor Immune Microenvironment: Expression, Function, Therapeutic Efficacy, and Resistance to Cancer Immunotherapy

2021 ◽  
Vol 9 ◽  
Author(s):  
Myeong Joon Kim ◽  
Sang-Jun Ha
Keyword(s):  
T Cells ◽  
Cancer Immunotherapy ◽  
Tumor Cells ◽  
Immune Cells ◽  
Immune Checkpoint ◽  
Immune Escape ◽  
Immune Microenvironment ◽  
Patients With Cancer ◽  
Tumor Immune Microenvironment

In the tumor immune microenvironment (TIME), tumor cells interact with various cells and operate various strategies to avoid antitumor immune responses. These immune escape strategies often make the TIME resistant to cancer immunotherapy. Neutralizing immune escape strategies is necessary to overcome resistance to cancer immunotherapy. Immune checkpoint receptors (ICRs) expressed in effector immune cells inhibit their effector function via direct interaction with immune checkpoint ligands (ICLs) expressed in tumor cells. Therefore, blocking ICRs or ICLs has been developed as a promising cancer immunotherapy by reinvigorating the function of effector immune cells. Among the ICRs, programmed cell death 1 (PD-1) has mainly been antagonized to enhance the survival of human patients with cancer by restoring the function of tumor-infiltrating (TI) CD8+ T cells. It has been demonstrated that PD-1 is expressed not only in TI CD8+ T cells, but also in other TI immune cells and even tumor cells. While PD-1 suppresses the function of TI CD8+ T cells, it is controversial whether PD-1 suppresses or amplifies the suppressive function of TI-suppressive immune cells (e.g., regulatory T cells, tumor-associated macrophages, and myeloid cells). There is also controversy regarding the role of tumor-expressing PD-1. Therefore, a precise understanding of the expression pattern and function of PD-1 in each cell subset is important for improving the efficacy of cancer immunotherapy. Here, we review the differential role of PD-1 expressed by various TI immune cells and tumor cells. We focused on how cell-type-specific ablation or blockade of PD-1 affects tumor growth in a murine tumor model. Furthermore, we will also describe how the blockade of PD-1 acts on TI immune cells in human patients with cancer.

Regulation of tumor immune microenvironment by sphingolipids and lysophosphatidic acid

2021 ◽  
Vol 22 ◽  
Author(s):  
Supriya Vishwakarma ◽  
Neha Arya ◽  
Ashok Kumar
Keyword(s):  
Extracellular Matrix ◽  
Tumor Microenvironment ◽  
Lysophosphatidic Acid ◽  
Immune Cells ◽  
Cancer Therapeutics ◽  
Immune Microenvironment ◽  
Tumor Immune Microenvironment ◽  
Sphingosine 1 Phosphate ◽  
Patient Prognosis

: The tumor microenvironment (TME) consists of cancer cells that interact with stromal components such as the extracellular matrix, blood, and lymphatic networks, fibroblasts, adipocytes, and the cells of the immune system. Further, the tumor immune microenvironment, majorly represented by the tumor-infiltrating immune cells (TIIC), plays an important role in cancer therapeutics and patient prognosis. In fact, a high density of TIICs within the tumor microenvironment is known to be associated with better outcomes in several types of cancers. Towards this, two bioactive lipid molecules, lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) regulate the homing of immune cells to the TME. In the present review, we will uncover the role of LPA and S1P signaling in the tumor immune environment, highlighting the latest progress in this field.

scholarly journals Microfluidic tumor-on-a-chip model to evaluate the role of tumor environmental stress on NK cell exhaustion

2021 ◽  
Vol 7 (8) ◽  
pp. eabc2331 ◽  
Author(s):  
Jose M. Ayuso ◽  
Shujah Rehman ◽  
Maria Virumbrales-Munoz ◽  
Patrick H. McMinn ◽  
Peter Geiger ◽  
...  
Keyword(s):  
Nk Cells ◽  
Immune Cells ◽  
Molecular Mechanisms ◽  
Nk Cell ◽  
Checkpoint Inhibitors ◽  
Waste Product ◽  
Extended Period ◽  
Cell Exhaustion

Solid tumors generate a suppressive environment that imposes an overwhelming burden on the immune system. Nutrient depletion, waste product accumulation, hypoxia, and pH acidification severely compromise the capacity of effector immune cells such as T and natural killer (NK) cells to destroy cancer cells. However, the specific molecular mechanisms driving immune suppression, as well as the capacity of immune cells to adapt to the suppressive environment, are not completely understood. Thus, here, we used an in vitro microfluidic tumor-on-a-chip platform to evaluate how NK cells respond to the tumor-induced suppressive environment. The results demonstrated that the suppressive environment created by the tumor gradually eroded NK cell cytotoxic capacity, leading to compromised NK cell surveillance and tumor tolerance. Further, NK cell exhaustion persisted for an extended period of time after removing NK cells from the microfluidic platform. Last, the addition of checkpoint inhibitors and immunomodulatory agents alleviated NK cell exhaustion.

scholarly journals The effect of PEGylation on the efficacy and uptake of an immunostimulatory nanoparticle in the tumor immune microenvironment

2021 ◽  
Author(s):  
Wyatt M. Becicka ◽  
Peter Bielecki ◽  
Morgan Lorkowski ◽  
Taylor J. Moon ◽  
Yahan Zhang ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Immune Microenvironment ◽  
Tumor Immune Microenvironment ◽  
Immunosuppressive Tumor Microenvironment

The efficacy of immunotherapies is often limited by the immunosuppressive tumor microenvironment, which is populated with dysfunctional innate immune cells. To reprogram the tumor-resident innate immune cells, we developed an...

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