scholarly journals A New Mathematical Model for Controlling Tumor Growth Based on Microenvironment Acidity and Oxygen Concentration

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
F. Pourhasanzade ◽  
S. H. Sabzpoushan

Hypoxia and the pH level of the tumor microenvironment have a great impact on the treatment of tumors. Here, the tumor growth is controlled by regulating the oxygen concentration and the acidity of the tumor microenvironment by introducing a two-dimensional multiscale cellular automata model of avascular tumor growth. The spatiotemporal evolution of tumor growth and metabolic variations is modeled based on biological assumptions, physical structure, states of cells, and transition rules. Each cell is allocated to one of the following states: proliferating cancer, nonproliferating cancer, necrotic, and normal cells. According to the response of the microenvironmental conditions, each cell consumes/produces metabolic factors and updates its state based on some stochastic rules. The input parameters are compatible with cancer biology using experimental data. The effect of neighborhoods during mitosis and simulating spatial heterogeneity is studied by considering multicellular layer structure of tumor. A simple Darwinist mutation is considered by introducing a critical parameter ( Nmm ) that affects division probability of the proliferative tumor cells based on the microenvironmental conditions and cancer hallmarks. The results show that Nmm regulation has a significant influence on the dynamics of tumor growth, the growth fraction, necrotic fraction, and the concentration levels of the metabolic factors. The model not only is able to simulate the in vivo tumor growth quantitatively and qualitatively but also can simulate the concentration of metabolic factors, oxygen, and acidity graphically. The results show the spatial heterogeneity effects on the proliferation of cancer cells and the rest of the system. By increasing Nmm , tumor shrinkage and significant increasing in the oxygen concentration and the pH value of the tumor microenvironment are observed. The results demonstrate the model’s ability, providing an essential tool for simulating different tumor evolution scenarios of a patient and reliable prediction of spatiotemporal progression of tumors for utilizing in personalized therapy.

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 5011
Author(s):  
Marija Gjorgoska ◽  
Tea Lanišnik Rižner

Ovarian cancer is a heterogeneous disease affecting the aging ovary, in concert with a complex network of cells and signals, together representing the ovarian tumor microenvironment. As in the “Schrödinger’s cat” thought experiment, the context-dependent constituents of the—by the time of diagnosis—well-established tumor microenvironment may display a tumor‑protective and ‑destructive role. Systemic and locally synthesized estrogens contribute to the formation of a pro-tumoral microenvironment that enables the sustained tumor growth, invasion and metastasis. Here we focus on the estrogen biosynthetic and metabolic pathways in ovarian cancer and elaborate their actions on phenotypically plastic, estrogen-responsive, aging immune cells of the tumor microenvironment, altogether highlighting the multicomponent-connectedness and complexity of cancer, and contributing to a broader understanding of the ovarian cancer biology.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xingxing Liu ◽  
Jiaru Fang ◽  
Shuang Huang ◽  
Xiaoxue Wu ◽  
Xi Xie ◽  
...  

AbstractCancer is one of the leading causes of human death, despite enormous efforts to explore cancer biology and develop anticancer therapies. The main challenges in cancer research are establishing an efficient tumor microenvironment in vitro and exploring efficient means for screening anticancer drugs to reveal the nature of cancer and develop treatments. The tumor microenvironment possesses human-specific biophysical and biochemical factors that are difficult to recapitulate in conventional in vitro planar cell models and in vivo animal models. Therefore, model limitations have hindered the translation of basic research findings to clinical applications. In this review, we introduce the recent progress in tumor-on-a-chip devices for cancer biology research, medicine assessment, and biomedical applications in detail. The emerging tumor-on-a-chip platforms integrating 3D cell culture, microfluidic technology, and tissue engineering have successfully mimicked the pivotal structural and functional characteristics of the in vivo tumor microenvironment. The recent advances in tumor-on-a-chip platforms for cancer biology studies and biomedical applications are detailed and analyzed in this review. This review should be valuable for further understanding the mechanisms of the tumor evolution process, screening anticancer drugs, and developing cancer therapies, and it addresses the challenges and potential opportunities in predicting drug screening and cancer treatment.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Loise Francisco-Anderson ◽  
Loise Francisco-Anderson ◽  
Mary Abdou ◽  
Michael Goldberg ◽  
Erin Troy ◽  
...  

BackgroundThe small intestinal axis (SINTAX) is a network of anatomic and functional connections between the small intestine and the rest of the body. It acts as an immunosurveillance system, integrating signals from the environment that affect physiological processes throughout the body. The impact of events in the gut in the control of tumor immunity is beginning to be appreciated. We have previously shown that an orally delivered single strain of commensal bacteria induces anti-tumor immunity preclinically via pattern recognition receptor-mediated activation of innate and adaptive immunity. Some bacteria produce extracellular vesicles (EVs) that share molecular content with the parent bacterium in a particle that is roughly 1/1000th the volume in a non-replicating form. We report here an orally-delivered and gut-restricted bacterial EV which potently attenuates tumor growth to a greater extent than whole bacteria or checkpoint inhibition.MethodsEDP1908 is a preparation of extracellular vesicles produced by a gram-stain negative strain of bacterium of the Oscillospiraceae family isolated from a human donor. EDP1908 was selected for its immunostimulatory profile in a screen of EVs from a range of distinct microbial strains. Its mechanism of action was determined by ex vivo analysis of the tumor microenvironment (TME) and by in vitro functional studies with murine and human cells.ResultsOral treatment of tumor-bearing mice with EDP1908 shows superior control of tumor growth compared to checkpoint inhibition (anti-PD-1) or an intact microbe. EDP1908 significantly increased the percentage of IFNγ and TNF producing CD8+ CTLs, NK cells, NKT cells and CD4+ cells in the tumor microenvironment (TME). EDP1908 also increased tumor-infiltrating dendritic cells (DC1 and DC2). Analysis of cytokines in the TME showed significant increases in IP-10 and IFNg production in mice treated with EDP1908, creating an environment conducive to the recruitment and activation of anti-tumor lymphocytes.ConclusionsThis is the first report of striking anti-tumor effects of an orally delivered microbial extracellular vesicle. These data point to oral EVs as a new class of immunotherapeutic drugs. They are particularly effective at harnessing the biology of the small intestinal axis, acting locally on host cells in the gut to control distal immune responses within the TME. EDP1908 is in preclinical development for the treatment of cancer.Ethics ApprovalPreclinical murine studies were conducted under the approval of the Avastus Preclinical Services’ Ethics Board. Human in vitro samples were attained by approval of the IntegReview Ethics Board; informed consent was obtained from all subjects.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Farias ◽  
A. Soto ◽  
F. Puttur ◽  
C. J. Goldin ◽  
S. Sosa ◽  
...  

AbstractBrucella lumazine synthase (BLS) is a homodecameric protein that activates dendritic cells via toll like receptor 4, inducing the secretion of pro-inflammatory cytokines and chemokines. We have previously shown that BLS has a therapeutic effect in B16 melanoma-bearing mice only when administered at early stages of tumor growth. In this work, we study the mechanisms underlying the therapeutic effect of BLS, by analyzing the tumor microenvironment. Administration of BLS at early stages of tumor growth induces high levels of serum IFN-γ, as well as an increment of hematopoietic immune cells within the tumor. Moreover, BLS-treatment increases the ratio of effector to regulatory cells. However, all treated mice eventually succumb to the tumors. Therefore, we combined BLS administration with anti-PD-1 treatment. Combined treatment increases the outcome of both monotherapies. In conclusion, we show that the absence of the therapeutic effect at late stages of tumor growth correlates with low levels of serum IFN-γ and lower infiltration of immune cells in the tumor, both of which are essential to delay tumor growth. Furthermore, the combined treatment of BLS and PD-1 blockade shows that BLS could be exploited as an essential immunomodulator in combination therapy with an immune checkpoint blockade to treat skin cancer.


2021 ◽  
Vol 22 (7) ◽  
pp. 3578
Author(s):  
Federico Armando ◽  
Adnan Fayyad ◽  
Stefanie Arms ◽  
Yvonne Barthel ◽  
Dirk Schaudien ◽  
...  

Histiocytic sarcomas refer to highly aggressive tumors with a poor prognosis that respond poorly to conventional treatment approaches. Oncolytic viruses, which have gained significant traction as a cancer therapy in recent decades, represent a promising option for treating histiocytic sarcomas through their replication and/or by modulating the tumor microenvironment. The live attenuated canine distemper virus (CDV) vaccine strain Onderstepoort represents an attractive candidate for oncolytic viral therapy. In the present study, oncolytic virotherapy with CDV was used to investigate the impact of this virus infection on tumor cell growth through direct oncolytic effects or by virus-mediated modulation of the tumor microenvironment with special emphasis on angiogenesis, expression of selected MMPs and TIMP-1 and tumor-associated macrophages in a murine xenograft model of canine histiocytic sarcoma. Treatment of mice with xenotransplanted canine histiocytic sarcomas using CDV induced overt retardation in tumor progression accompanied by necrosis of neoplastic cells, increased numbers of intratumoral macrophages, reduced angiogenesis and modulation of the expression of MMPs and TIMP-1. The present data suggest that CDV inhibits tumor growth in a multifactorial way, including direct cell lysis and reduction of angiogenesis and modulation of MMPs and their inhibitor TIMP-1, providing further support for the concept of its role in oncolytic therapies.


Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3377
Author(s):  
Panagiota Economopoulou ◽  
Ioannis Kotsantis ◽  
Amanda Psyrri

The tumor microenvironment (TME) encompasses cellular and non-cellular components which play an important role in tumor evolution, invasion, and metastasis. A complicated interplay between tumor cells and adjacent TME cells, such as stromal cells, immune cells, inflammatory cells, and cytokines, leads to severe immunosuppression and the proliferation of cancer cells in several solid tumors. An immunosuppressive TME has a significant impact on treatment resistance and may guide response to immunotherapy. In head and neck cancer (HNC), immunotherapeutic drugs have been incorporated in everyday clinical practice. However, despite an exceptional rate of durable responses, only a low percentage of patients respond. In this review, we will focus on the complex interactions occurring in this dynamic system, the TME, which orchestrate key events that lead to tumor progression, immune escape, and resistance. Furthermore, we will summarize current clinical trials that depict the TME as a potential therapeutic target for improved patient selection.


2017 ◽  
Vol 6 (10) ◽  
pp. 2308-2320 ◽  
Author(s):  
Hiroyuki Kitano ◽  
Yasuhiko Kitadai ◽  
Jun Teishima ◽  
Ryo Yuge ◽  
Shunsuke Shinmei ◽  
...  

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