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

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunkai Yang ◽  
Yan Wang

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.

Author(s):  
Myeong Joon Kim ◽  
Sang-Jun Ha

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.


Author(s):  
Yalu Zhang ◽  
Qiaofei Liu ◽  
Quan Liao

Abstract Long noncoding RNAs (lncRNAs) are a class of endogenous, non-protein coding RNAs that are highly linked to various cellular functions and pathological process. Emerging evidence indicates that lncRNAs participate in crosstalk between tumor and stroma, and reprogramming of tumor immune microenvironment (TIME). TIME possesses distinct populations of myeloid cells and lymphocytes to influence the immune escape of cancer, the response to immunotherapy, and the survival of patients. However, hitherto, a comprehensive review aiming at relationship between lncRNAs and TIME is missing. In this review, we focus on the functional roles and molecular mechanisms of lncRNAs within the TIME. Furthermore, we discussed the potential immunotherapeutic strategies based on lncRNAs and their limitations.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yingying Xing ◽  
Guojing Ruan ◽  
Haiwei Ni ◽  
Hai Qin ◽  
Simiao Chen ◽  
...  

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.


Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1398 ◽  
Author(s):  
Christina Piperi ◽  
Kostas A. Papavassiliou ◽  
Athanasios G. Papavassiliou

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.


2021 ◽  
Vol 22 (19) ◽  
pp. 10268
Author(s):  
Liang Yan ◽  
Yanlian Tan ◽  
Guo Chen ◽  
Jun Fan ◽  
Jun Zhang

Immune escape is one of the hallmarks of cancer. While metabolic reprogramming provides survival advantage to tumor cancer cells, accumulating data also suggest such metabolic rewiring directly affects the activation, differentiation and function of immune cells, particularly in the tumor microenvironment. Understanding how metabolic reprogramming affects both tumor and immune cells, as well as their interplay, is therefore critical to better modulate tumor immune microenvironment in the era of cancer immunotherapy. In this review, we discuss alterations in several essential metabolic pathways in both tumor and key immune cells, provide evidence on their dynamic interaction, and propose innovative strategies to improve cancer immunotherapy via the modulation of metabolic pathways.


2021 ◽  
Vol 22 ◽  
Author(s):  
Supriya Vishwakarma ◽  
Neha Arya ◽  
Ashok Kumar

: 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.


Author(s):  
Jiayao Ma ◽  
Lingjuan Huang ◽  
Die Hu ◽  
Shan Zeng ◽  
Ying Han ◽  
...  

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.


2021 ◽  
Author(s):  
Linchong Sun ◽  
Huafeng Zhang ◽  
Ping Gao

AbstractMetabolic rewiring and epigenetic remodeling, which are closely linked and reciprocally regulate each other, are among the well-known cancer hallmarks. Recent evidence suggests that many metabolites serve as substrates or cofactors of chromatin-modifying enzymes as a consequence of the translocation or spatial regionalization of enzymes or metabolites. Various metabolic alterations and epigenetic modifications also reportedly drive immune escape or impede immunosurveillance within certain contexts, playing important roles in tumor progression. In this review, we focus on how metabolic reprogramming of tumor cells and immune cells reshapes epigenetic alterations, in particular the acetylation and methylation of histone proteins and DNA. We also discuss other eminent metabolic modifications such as, succinylation, hydroxybutyrylation, and lactylation, and update the current advances in metabolism- and epigenetic modification-based therapeutic prospects in cancer.


2021 ◽  
Author(s):  
Wyatt M. Becicka ◽  
Peter Bielecki ◽  
Morgan Lorkowski ◽  
Taylor J. Moon ◽  
Yahan Zhang ◽  
...  

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...


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e12573-e12573
Author(s):  
Yoshihisa Tokumaru ◽  
Masanori Oshi ◽  
Vijayashree Murthy ◽  
Eriko Katsuta ◽  
Nobuhisa Matsuhashi ◽  
...  

e12573 Background: In breast cancer patients, it is well known that the elevation of neutrophil lymphocyte ratio (NLR) in the blood are reported to associate with poor prognosis based on the notion that neutrophils represent pro-cancer, and lymphocytes represent anti-cancer immune cells. Tumor immune microenvironment has been demonstrated to play critical roles in the outcome of breast cancer patients. However, there is scarce evidence on the clinical relevance of intratumoral NLR in breast cancer patients. In the current study, we hypothesized that intratumoral NLR high tumors are associated with worse survival particularly in TNBC that is known to have high immune cell infiltration. Methods: A total of 1904 breast cancer patients’ data from METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) and analyzed. NLR was calculated by the gene expressions of CD66b (CEACAM8) and CD8 (CD8A). NLR high and low were divided by the median. Overall Survival (OS) and Disease-Free Survival were calculated utilizing Kaplan Meier method between intratumoral NLR high and low groups. xCell algorithm was used to analyze the infiltrated immune cells within the tumor immune microenvironment as we have previously published. Results: Intratumoral NLR high group was associated with worse OS in whole, ER-positive/HER2-negative, and triple negative (TN) subtypes, in agreement with the previous studies. TN subtype alone demonstrated worse DFS of NLR high group. Surprisingly, gene set enrichment analysis (GSEA) demonstrated no gene set enrichment to NLR high group, which implicates that there is no distinctive mechanism that associate with worse survival. Whereas, immune response-related gene sets significantly enriched to NLR low group in TN subtype. This enrichment was consistent in ER-positive/HER2-negative. Compared with ER-positive/HER2-negative subtype, anti-cancer immune cells such as CD4+ T cells, CD8+ T cells, M1 macrophage, and helper T helper type 1 cells were significantly infiltrated in TN patients (p < 0.001 for all genes), where M2 macrophages and neutrophils were less and regulatory T cells and T helper type 2 cells were more infiltrated in TN subtype. Furthermore, intratumoral NLR was significantly lower in TN compared with ER-positive/HER2-negative subtype (p < 0.001). These results suggest that intratumoral NLR low group is associated with better survival due to favorable tumor immune microenvironment in TN subtype rather than NLR high group has worse survival. Conclusions: Intratumoral NLR low tumor demonstrated more favorable OS and more favorable DFS in TN patients. Intratumoral NLR low breast cancer was associated with enhanced immune response and higher infiltration of anti-cancer immune cells were observed in TN subtype compared to ER-positive/HER2-negative which may contribute to the favorable outcome of in TN breast cancer.


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