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Tumor microenvironment modulation and the impact on cancer immunotherapy
Musil, Jan
Modulation of the tumor microenvironment represents a possible way to inhibit cancer growth and enhance anti-cancer immune responses. In the presented work we employ two strategies for tumor microenvironment modulation. Firstly, we have constructed rVACV co-expressing the tumor suppressor gene insulin-like growth factor-binding protein-3 (IGFBP- 3) and the fusion gene encoding the immunogen SigE7LAMP. The expression of IGFBP-3 was regulated either by the early vaccinia virus H5 promoter or by the synthetic early/late (E/L) promoter. We have shown that expression of IGFBP-3 regulated by the H5 promoter yielded higher amounts of IGFBP-3 protein when compared with the E/L promoter. Immunization with P13-SigE7LAMP-H5-IGFBP-3 was more effective in inhibiting the growth of TC-1 tumors in mice and elicited a higher T-cell response against VACV-encoded antigens than the control virus P13-SigE7LAMP-TK- . We found that high-level production of IGFBP-3 enhanced virus replication both in vitro and in vivo, resulting in profound antigen stimulation. Production of IGFBP-3 was associated with a higher adsorption rate of P13-SigE7LAMP-H5-IGFBP-3 to CV-1 cells when compared with P13-SigE7LAMP-TK- . We have identified two structural differences between the IMVs of the IGFBP-3 expressing virus P13-SigE7LAMP-H5-IGFBP-3...
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Myeloid - Derived Suppressor Cell in the Context of Tumor Microenvironment
Košťálová, Monika ; Šírová, Milada (advisor) ; Indrová, Marie (referee)
Today, tumors are considered not only as a complex of genetically mutated cells with pathological function of excessive proliferation, invasiveness and increased viability, but increased attention is paid for the tumor microenvironment created by the tumor itself. This microenvironment generates conditions, which differ from the normal tissues - for example local hypoxia, lactic acidosis and tumor- induced immunosupression - all these abnormalities lead to increased viability of the tumor tissue. Myeloid-derived suppressor cells (MDSCs) seem to be one of the main mediators of the escape from immunosurveillance. MDSCs represent a heterogenous cell population of myeloid origin. In active state, MDSCs produce enhanced amount of reactive oxygen species, nitrogen compounds and arginase, which represent the mechanisms of the suppression of the anti-tumor immune response. That makes MDSCs a promising therapeutic target. However, recent studies also point out the physiological role of MDSCs, which seems to be essential to consider for succesfull MDSCs targeting. Key words: Tumor microenvironment, immunosurveillance theory, immunoediting, myeloid-derived suppressor cells, immunosuppresion in tumors, therapeutic targeting of MDSCs, physiological role of MDSCs Powered by TCPDF (www.tcpdf.org)
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Intercellular interactions in malignant melanoma
Nedvědová, Tereza ; Dvořánková, Barbora (advisor) ; Brábek, Jan (referee)
Melanomas are one of the most aggressive types of tumours, with increasing incidence, high mortality and high potential to metastasize to a variety of diverse locations. The aim of this thesis was to study the tumour as a complex structure consisting not only of tumour cells but also of tumour stroma. Stromal cells play a major role in cancer biology. This is well documented for example in squamous cell epithelium tumours of the head and neck. Similar mechanisms can be expected to occur in melanomas. In the first experiment, we simulated the conditions in vivo during the metastatic process and studied the influence of non-adhesive environment both with and without the influence of stromal fibroblasts. The presented data demonstrates a change of tumour cells' phenotype leading to increased plasticity of the melanoma cells in these conditions. It also indicates the crucial role of stromal fibroblasts in interactions with melanoma cells. Cancer cell lines show variability in their behaviour, which is in accordance with well-known melanoma heterogeneity in clinical practice. The previous experiments in our laboratory indicate that cancer associated fibroblasts are able to influence the phenotype of a tumour cell line and this effect is based on a tumour type-unspecific mechanism. In the second part of...
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Tumor microenvironment modulation and the impact on cancer immunotherapy
Musil, Jan ; Němečková, Šárka (advisor) ; Mikyšková, Romana (referee) ; Otáhal, Pavel (referee)
Modulation of the tumor microenvironment represents a possible way to inhibit cancer growth and enhance anti-cancer immune responses. In the presented work we employ two strategies for tumor microenvironment modulation. Firstly, we have constructed rVACV co-expressing the tumor suppressor gene insulin-like growth factor-binding protein-3 (IGFBP- 3) and the fusion gene encoding the immunogen SigE7LAMP. The expression of IGFBP-3 was regulated either by the early vaccinia virus H5 promoter or by the synthetic early/late (E/L) promoter. We have shown that expression of IGFBP-3 regulated by the H5 promoter yielded higher amounts of IGFBP-3 protein when compared with the E/L promoter. Immunization with P13-SigE7LAMP-H5-IGFBP-3 was more effective in inhibiting the growth of TC-1 tumors in mice and elicited a higher T-cell response against VACV-encoded antigens than the control virus P13-SigE7LAMP-TK- . We found that high-level production of IGFBP-3 enhanced virus replication both in vitro and in vivo, resulting in profound antigen stimulation. Production of IGFBP-3 was associated with a higher adsorption rate of P13-SigE7LAMP-H5-IGFBP-3 to CV-1 cells when compared with P13-SigE7LAMP-TK- . We have identified two structural differences between the IMVs of the IGFBP-3 expressing virus P13-SigE7LAMP-H5-IGFBP-3...
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New ferritin nanoparticles for specific targeting of experimental melanoma in mice: in vitro and in vivo tests.
Rajsiglová, Lenka ; Vannucci, Luca Ernesto (advisor) ; Šírová, Milada (referee)
Cancer diseases represent second most frequent cause of death after cardiovascular diseases in Europe. Nowadays used medical treatments like chemotherapy and radiotherapy are nonspecific and cause huge side effects. Various systems to deliver therapy directly inside the tumour microenvironment and reduce side effects are under development. Protein nanoparticles seem to be very promising strategy to achieve that goal. Our group in cooperation with CNR in Rome tested nanoparticles based on heavy chain of human ferritine. These constructs, modified to expose the tumor targeting molecule, were able to be specifically internalised by B16F10 melanoma cells in vitro. They also specifically target and localise at the sites of primary melanoma and lung metastases of different size in mouse in vivo model. These nanoparticles can carry either therapeutic or diagnostic molecules. Thus they represent a suitable candidate for further studies for potential use in clinical praxis as a diagnostic and/or therapeutic agents (theranostics). Powered by TCPDF (www.tcpdf.org)
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Cellular senescence escape mechanisms - anti-cancer barrier
Davidová, Eliška ; Hodný, Zdeněk (advisor) ; Horníková, Daniela (referee)
Cancer is one of the most dangerous diseases of the modern world. Therefore, many world laboratories engaged in research into the causes leading to the outbreak of this insidious disease. In this context, it has already been found that the normal animal cells do not divide indefinitely, but have a finite replicative life span. After this period, cells undergo either apoptotic processes or enter into so-called senescence, typical for proliferation arrest, but preserved metabolic processes. Further research has revealed that senescence serves as an effective anticancer program and currently is shed light on its significance in relation to various physiological or pathological processes associated with aging. In this work, the focus is on the role of senescence as a barrier for cancer development, and effectiveness. It can be assumed, that if the senescent cycle arrest functioned perfectly, the incidence of cancer among people would be recorded in much lower extent. The aim of this thesis is the current knowledge about the physiological and pathological roles of senescence and possible causes of overcoming this barrier, the result may be the uncontrolled cell division and tumorigenicity.
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Impacts of chemotherapy on imunoregulatory gene expression in the tumor microenvironment
Paračková, Zuzana ; Reiniš, Milan (advisor) ; Zajícová, Alena (referee)
Tumor microenvironment is an area, where the local immunosuppressive effects dominate and prevents the immune system to perform its physiological functions. The cells infiltrating the microenvironment have an important function among many cell types since they produce a large quantity of factors suppressing the immune response. In our work, we monitored the immune changes in the microenvironment during tumor growth and chemotherapy. For these purposes, we utilized the methods for analysis of the proportion and phenotype of the distinct populations of immunocytes and for analysis of the total level of expressions of selected genes associated with immunosuppression or with distinct populations of immunocytes. The aim of our work was to discover, using two types of mouse tumors (TRAMP-C2 and TC-1/A9), how 5-azacytidine (5AC), a cytostatic drug with epigenetic activity, affects the proportion of leukocytes infiltrating the tumor microenvironment and, further, whether these changes are accompanied by decreased expression of immunosuppressing genes. In addition, we have also focused on the changes of relative expression of genes encoding markers of lymphoid lines and, on other immunoregulating genes, encoding IL-6, IL-10, IL-12, IL-4 and IFNγ cytokines, in the microenvironment of these tumors....
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"Features of the tumor microenvironment and their utilisation for drug delivery"
Větvička, David ; Hovorka, Ondřej (advisor) ; Reiniš, Milan (referee) ; Drbal, Karel (referee)
- David Větvička, M.Sc . Many researchers have, in the past, focused on pathophysiological features of tumor tissue, various tumor-nonmalignant cell interactions, and secretion of active molecules within the tumor mass. All these aspects of tumor structure are known as tumor microenvironment. The composition of particular tumor ecosystem is highly variable, with differences between various tumor types, even between patients with the same diagnosis, and in separate areas of the same tumor. Moreover, further changes in tumor microenvironment often occur during the progression of the disease. Studies of tumor microenvironment have revealed both novel targets for therapy and new prognostic markers. New therapy modalities are being developed to target these discovered features, including drugs functioning to boost anti-malignancy immunity, to block pro-metastatic potential, or to utilize the unique features of this pathological environment established by the tumor. These are obviously of great interest and harbor high potential for better management of malignant diseases. The focus of this thesis is to study the interactions of polymeric drug delivery systems within the tumor microenvironment and to utilize various features of this specific niche for drug delivery research. We have followed three...
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Tumor microenvironment: Cancer-associated fibroblasts and their biological function in tumors derived from squamous epithelium
Nedvědová, Tereza ; Kodet, Ondřej (advisor) ; Brábek, Jan (referee)
The incidence of carcinomas originating from squamous cell epithelium increases with population ageing as well as in younger people. The treatment is demanding for both the patient and whole health system. For the successful therapy, there is a need to understand the development and spreading of the tumor to target them specifically. Tumors consist of tumor stroma and malignant cells. Cancer cells are organized in a hierarchic order and the major problem are cancer stem cells. Adult stem cells are defined as cells with the capacity to self-renew as well as the ability to generate differentiated cells within the tumor. Resistance to targeted therapy can improve survival of these cells and is responsible for cancer relapse. Tumor stroma constitutes another important part of tumor. It is composed of non-cancer cells and extracellular matrix and has become recognized as a major factor in cancer growth and metastation. The stroma includes vascular and immune cells and especially cancer associated fibroblasts (CAFs). These cells are not malignant per se, nevertheless their role in supporting cancer growth and survival is important, so they have become an attractive target for treatment. There are several hypotheses made to explain the origin of CAFs. The question is whether the origin of all CAFs in one...
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Tumor microenvironment and the importance of anti-tumor immunity for clinical course of human cancers
Partlová, Simona ; Špíšek, Radek (advisor) ; Drbal, Karel (referee) ; Kovář, Marek (referee)
Cancer development and progression vary depending on tumor type, localization, invasion, immunogenicity and the ability of immune system to become activated. There are frequent interactions between tumor cells and immune cells, occuring locally at the site of primary tumor or distally through paracrine signalling of various mediators and cytokines. The main subject of this PhD thesis is to study key factors and aspects of immune response in cancer patients. In the first part, we analyzed immune cells infiltrating tumor tissues of ovarian cancer patients at different stages of disease. We focused on the dynamics of immune response, primarily on frequency of individual T lymphocyte populations in peripheral blood and tumor infiltrating T lymphocytes in tumors of early and advanced stages of ovarian cancer. We found that during disease progression there is a gradual decrease of proinflammatory Th17 and Th1 immune responses and a specific recruitment of regulatory T cells to the tumor site, which results in a significant immune suppression in the tumor microenvironment. In the second part, we demonstrated that the character of immune response in HPV-positive head and neck cancer patients is very different from the patients with tumors not associated with HPV infection. In HPV-positive patients, significantly...
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