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Mutual communication and relationship between tumor cells and the tumor microenvironment
Novák, Štěpán ; Szabo, Pavol (advisor) ; Krška, Zdeněk (referee) ; Grobárová, Valéria (referee)
The present dissertation addresses two main objectives. First, the interaction between four pancreatic ductal adenocarcinoma (PDAC) cell lines and conditioned media from normal/healthy fibroblasts was investigated, HF) and cancer- associated fibroblasts (CAFs) derived from PDAC (PDAC-derived CAFs, PANFs), cells derived from ascitic fluid of patients with end-stage PDAC and primary PDAC tumor. Subsequently, the genome-wide profile of PANFs was determined. The second aim was to differentiate squamous cell carcinoma (SCC) cells, surgical resection margin (MSR) cells and normal mucosa (NM) cells in patients operated for head and neck squamous cell carcinoma (HNSCC) by immunohistochemistry, using detection of tenascin (Ten), fibronectin (Fn) and galectin-1 (Gal-1), and to correlate these results with their clinical characteristics. Subsequently, whole-genome profiling of SCC, MSR and NM samples was performed based on Ten expression stratification. Results Cultivation of the four PDAC lines under the influence of conditioned media from HF and PANF was heterogeneous. After stimulation, the most aggressive behavior was obtained in the Panc-1 cell line while the PaTu-8902 line was rather inhibited by the media. The PANF transcriptome showed increased expression of some genes (e.g. IL-6, IL-8, MFGE8,...
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Pathofysiology of a tumour microenvironment of salivary glands cancer
Kuchař, Martin ; Skřivan, Jiří (advisor) ; Pokorný, Jaroslav (referee) ; Lohynská, Radka (referee)
Treatment options for salivary gland carcinomas (SGC), especially advanced ones, are limited. Immunotherapy, particularly therapy with immune checkpoint inhibitors (ICI), has brought significant progress and change in the treatment of malignant tumors. The effect and response to immunotherapy using ICI are largely driven by the characteristics of immune cells in the tumor tissue and, as it turns out, also in the peritumoral tissue. We conducted an immunohistochemical analysis of the expression of the immune checkpoint protein PD-1 and its ligand PD-L1 on the surface of tumor cells as well as tumor-infiltrating immune cells (TIIC) in samples of salivary carcinomas, separately in their centre and at their periphery. In addition to the above, an increasing amount of evidence suggests that resistance to ICI therapy is modulated by the interaction of the Fas receptor (CD95) and Fas ligand (FasL, CD178) between tumor cells and immune cells. We therefore decided to explore the expression and interaction of Fas-FasL between tumor cells and tumor-infiltrating immune cells in the centre of the tumor and in the peritumoral area of salivary carcinoma samples. Differential evaluation of the tumor centre and tumor periphery across various histological subtypes of SGC revealed the role of peripheral TIICs and...
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Small Molecules as Immune Modulators in Anticancer Therapy
Pavlovová, Anna ; Míšek, Jiří (advisor) ; Smrček, Stanislav (referee)
The aim of this bachelor thesis was to summarize knowledge about several selected therapeutic targets used for cancer immunotherapy and small molecules that can have an immunomodulatory effect on these targets. This is a relatively new and attractive topic in the field of biomedical sciences, which is constantly evolving. Some small molecules have already been approved for treatment of specific cancer diseases, and many more are currently undergoing various stages of clinical trials. This work should provide the reader with an overview of possible approaches to modulate the immune system using small molecules. Key words: small molecules, immunotherapy, cancer, checkpoint inhibitors, tumor microenvironment
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Inhibitory NK cell receptors and possibilities of manipulation of cytotoxic properties.
Švubová, Veronika ; Frič, Jan (advisor) ; Krulová, Magdaléna (referee)
Acute myeloid leukemia makes up for 18 % of all leukemias among pediatric and young adult patients. The complete remission rate (80-90 %) and the overall survival (70 %) of the patients is relatively high, nevertheless, the relapse rate is still almost at 50 % and the prognosis remains extremely bad. The relapse treatment is rather challenging because the persisting leukemic clones might in fact start to be refractory to chemotherapy. Lately, NK cells are being perceived as an attractive therapeutical tool for treatment of the relapses. NK cells are a subpopulation of innate lymphoid cells, possessing the ability to eliminate dysfunctional cells through cytotoxic activities and further perpetuate the immune response. One of the advantages of NK cells is their functional independency of specific antigens. In the light of growing evidence about the role of leukemic stem cells in context of acute myeloid leukemia, NK cells seem to offer a new perspective in therapeutical efforts to eliminate them via several cytotoxic mechanisms. Yet despite optimistic preliminary results, treating this disease has proved to be rather challenging and the NK cell-based immunotherapy is still facing several limitations. Transforming growth factor β is partially responsible for maintenance of leukemic stem cell...
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Tumor microenvironment of soft tissue sarcomas and it's predictive significance in modern oncological treatment
Ozaniak, Andrej ; Ozaniak Střížová, Zuzana (advisor) ; Büchler, Tomáš (referee) ; Posová, Helena (referee)
Soft tissue sarcomas (STSs) are malignant tumors of mesenchymal origin, characterized by an extreme heterogeneity in histological composition, biological behavior, and clinical manifestation. Most STSs are chemo- and radiotherapy resistant. A key prognostic factor predicting the risk of distant metastases and affecting the overall survival is the tumor grade. However, grade has not been associated with the risk of local recurrence. Radical surgical procedure is in many cases the only possible treatment modality or at least plays a main role in the multimodal treatment. For patients with distant metastases, the treatment options are very limited. The chemosensitivity of STSs is generally very low, with the exception of several less common subtypes, and accounts for only 5-10% of the cases. In many cases, radiotherapy is a standard part of the treatment protocol. It is usually given in either neoadjuvant or adjuvant settings. However, radiotherapy administration in generalized patients does not improve the prognosis. Cancer immunotherapy is a therapeutic modality that utilizes the physiological cytotoxic antitumoral abilities of the immune cells. Therefore, it does not target the rapidly proliferating tumor cells but rather stimulates the immune cells. A wide variety of different strategies have been...
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Multiple forms of dipeptidyl peptidase IV and fibroblast activation protein in brain tumors
Matrasová, Ivana ; Šedo, Aleksi (advisor) ; Kupcová Skalníková, Helena (referee) ; Modrianský, Martin (referee)
Proteolytic enzymes are known to contribute to the initiation, development and progression of a number of diseases. Dipeptidyl peptidase IV (DPP-IV) and fibroblast activation protein (FAP) are serine proteases with the unique ability to cleave dipeptides containing - highly evolutionarily conserved - proline at the penultimate position of the N- terminus of substrates/biologically active peptides. FAP also exhibits gelatinolytic activity, which it exerts during extracellular matrix remodeling processes. Glial brain tumors (gliomas) arise from resident transformed glial cells, whereas brain metastases originate from circulating transformed extracranial tumor cells. Our previous work has described an increased expression of DPP-IV and FAP in high-grade glioma tissues. The presence of DPP- IV and FAP in brain metastatic tissues has not been described to date. The aim of this thesis was to describe the multiple forms of DPP-IV and FAP, and to describe their cellular origin and possible regulation in brain tumors. DPP-IV and its molecular MW and pI forms were expressed predominantly by transformed glial cells, whereas FAP and its MW and pI forms were expressed by transformed and stromal cells present in GBM and brain metastatic tissues. The spectrum of multiple forms of DPP-IV and FAP in GBM tissues and...
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Combined immunotherapy of tumors with different expression of MHC class I molecules
Piataková, Adrianna Julia ; Šmahel, Michal (advisor) ; Krulová, Magdaléna (referee) ; Reiniš, Milan (referee)
Immunotherapy experienced ups and downs before being recognized as a paramount therapy for cancer. Evidence from the latest studies revealed that the tumour microenvironment (TME) plays a decisive role in the outcome of immunotherapeutic treatment. In addition, one of the mechanisms used by cancer cells to evade immunosurveillance is reduction of the expression of major histocompatibility complex class I (MHC-I), by which cancer cells become invisible to cytotoxic T lymphocytes (CTLs). Therefore, cancer immunotherapy should involve combined strategies to target both tumour cells and TME from different sites by activating other immune cells in addition to CTLs, such as tumour-associated macrophages (TAMs). This Ph.D. thesis aimed to investigate combined immunotherapy, composed of DNA immunization, immunostimulatory compounds, and an immune checkpoint inhibitor to activate adaptive and innate immunity and inhibit immunosuppression, respectively. For this purpose, murine models related to HPV-16-induced tumours with either reversibly (TC-1/A9 cell line) or irreversibly (TC-1/dB2m) reduced MHC-I expression were used. The development of the TC-1/dB2m clone was a part of this project and this clone was obtained by deactivating the B2m gene. An important focus of the research was the analysis of TAMs isolated from...
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Detection and characterization of macrophages in the tumors of viral and non-viral etiology
Dalewská, Natálie ; Tachezy, Ruth (advisor) ; Krulová, Magdaléna (referee)
Head and neck cancers are etiologically associated with smoking and alcohol consumption. Part of these tumors is induced by HPV and their incidence is increasing in the last decade. Patients with virally induced tumors have better prognosis even though they are usually diagnosed with tumors in advanced stage. One of the possible explanations may be better stimulation of the immune system by viral antigens. Macrophages are cells of the innate immune system which belong to professional phagocytes. They are called TAM upon infiltration to the tumor where they represent heterogeneous group of cells. Two main phenotypes are antitumor M1 and protumor M2 macrophages. TAMs are a major component of tumor microenvironment of many types of tumors, one of them are also head and neck cancers. In my thesis I focused on the immunohistochemical detection of M1 and M2 macrophages in the head and neck tumors of viral and non-viral etiology and at the same time RT-qPCR analyses of gene expression of macrophage-associated and/or immunosuppressive genes IDO1, ARG1, CD163, NOS2 a PTGS2 was performed. My data showed that HPV- negative tumors had higher number of M2 macrophages with typical markers CD163, ARG1 and PTGS2. It is known that patients with these tumors have worse prognosis of the disease. Due to high...
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Effect of cancer-associated fibroblasts on the survival, proliferation and invasiveness of cancer cells.
Nováková, Gita ; Anděra, Ladislav (advisor) ; Brábek, Jan (referee)
Tumour microenvironment, in addition to cancer cells themselves, represents important structural and functional part of the tumour. Similarly to the normal organs tumour microenvironment comprises several cell types (fibroblasts, immune cells, endothelial cells etc.) and non-cellular components, particularly extracellular matrix. All of them form favourable conditions for the growth, proliferation, protection from the immune system- mediated destruction and nutrition of cancer cells. Cancer associated fibroblasts (CAFs) represent the most abundant cell type of tumour microenvironment. Their origin can be traced to local normal fibroblasts, endothelial cells or epithelial cells and the transition into the CAFs phenotype is influenced with several factors secreted by cancer cells (particularly TGF-β). In contrast to fibroblasts activated during wound healing newly formed cancer associated fibroblasts expressing α-SMA are not subsequently eliminated from the respektive tissue. They persist and produce a number of pro-tumorigenic factors - SDF-1, HGF, IGF-1, IL-6, VEGF, PDGF-C, TGF-β, MMPs etc. CAFs and their secreted factors target several signalling pathways enhancing basic characteristics of the tumour, so called Hallmarks of Cancer. Cancer associated fibroblasts promote proliferation and invasiveness of...
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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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