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Mechanisms of phenotypic plasticity induced by genotoxic stress
Přibyl, Miroslav ; Hodný, Zdeněk (advisor) ; Remešová, Hana (referee) ; Vomastek, Tomáš (referee)
Therapy resistance of malignant cells represents the main reason responsible for the failure of cancer therapy. The growth of malignant cells at primary tumour sites but most importantly the dissemination of tumour cells and their growth at secondary sites, are the main reasons why patients eventually succumb to the disease. Even novel immune-based therapies find their limitation in most tumour types. The therapy resistance is mediated by the tumour cells but also by other cellular components of the tumour microenvironment. Understanding the tumour cells mechanisms and the tumour microenvironment features responsible for therapy resistance enables the development of novel therapeutic strategies. Here, we show that ionizing irradiation, 5-azacytidine, and IFNγ treatments induced expression of suprabasin (SBSN) and therapy-resistant low-adherent phenotype in cancer cells. Knockdown of SBSN resulted in suppression of the phenotype. Next, we identified aberrantly elevated SBSN in the bone marrow of a subgroup of myelodysplastic syndromes (MDS) patients. SBSN was expressed by myeloid-derived suppressor cells (MDSCs) and showed significant anti-correlation with T cell abundance and CCL2 levels, hence promises a prognostic value in clinical use. We compiled the most of the relevant knowledge of SBSN...
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Real-time monitoring of cellular processes - current approaches
Švecová, Iva ; Hodný, Zdeněk (advisor) ; Groušl, Tomáš (referee)
This thesis aims to provide an overview of real-time live-cell imaging methods with a focus on the signalling pathways. The first, most thorough section is about fluorescence methods and is followed by sections about bioluminescence and label-free methods. In the fluorescence section, we will at first introduce the types of fluorophores and respective labelling approaches. Subsequently, we will go through the individual techniques, starting with single-fluorophore and FRET biosensors, continuing with kinetic modelling approaches, a FLIM method used to detect changes in the cellular environment, and ending with two methods used to improve the resolution. With each technique, we will shortly explain the working principle and look at the examples at which this method was used. Finally, we will look at the example of live-cell imaging of one signalling cascade.
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Significance of protein phosphorylation for bacterial cell
Gregorová, Michaela ; Branny, Pavel (advisor) ; Lišková, Petra (referee)
Phosphorylation - most common post-translational modification has an important role in many cellular processes of bacteria. Bacteria contain enzymes that are in charge of adding phosphoryl group (kinases) or enzymes with reciprocal activity (phosphatases). Reversible phosphorylation and dephosphorylation of proteins are fundamental for signal transduction from the environment to the cell. These modifications can affect enzymatic activity, protein stability, localization as well as interaction with another protein. Due to the complexity of these phosphorylation networks, bacterial cells are capable to adapt very effectively to changing environmental conditions.
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Mechanisms of phenotypic plasticity induced by genotoxic stress
Přibyl, Miroslav ; Hodný, Zdeněk (advisor) ; Remešová, Hana (referee) ; Vomastek, Tomáš (referee)
Therapy resistance of malignant cells represents the main reason responsible for the failure of cancer therapy. The growth of malignant cells at primary tumour sites but most importantly the dissemination of tumour cells and their growth at secondary sites, are the main reasons why patients eventually succumb to the disease. Even novel immune-based therapies find their limitation in most tumour types. The therapy resistance is mediated by the tumour cells but also by other cellular components of the tumour microenvironment. Understanding the tumour cells mechanisms and the tumour microenvironment features responsible for therapy resistance enables the development of novel therapeutic strategies. Here, we show that ionizing irradiation, 5-azacytidine, and IFNγ treatments induced expression of suprabasin (SBSN) and therapy-resistant low-adherent phenotype in cancer cells. Knockdown of SBSN resulted in suppression of the phenotype. Next, we identified aberrantly elevated SBSN in the bone marrow of a subgroup of myelodysplastic syndromes (MDS) patients. SBSN was expressed by myeloid-derived suppressor cells (MDSCs) and showed significant anti-correlation with T cell abundance and CCL2 levels, hence promises a prognostic value in clinical use. We compiled the most of the relevant knowledge of SBSN...
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Establishment of Babesia laboratory model and its experimental application
JALOVECKÁ, Marie
Growing incidence of infections caused by the tick-transmitted protozoan parasite Babesia spp. defines babesiosis as an emerging disease from the aspect of human and veterinary medicine. The thesis provides an insight to biology of two main agents of human babesiosis, Babesia microti and Babesia divergens. We introduce here the fully optimized quantification model of Babesia parasite enabling the detailed investigation of the parasite developmental cycle and identification of molecules playing a role in its acquisition and transmission by the vector Ixodes ricinus. Novel and detailed information about Babesia dissemination within the tick tissues are given by newly implemented visualization and quantification techniques. Special emphasis is paid to parasite development in the tick salivary glands, the primary site responsible for parasite transmission from the vector into the host. Using gene-specific silencing we screene the tick immune pathways including effector molecules and evaluate their role in Babesia acquisition. We also provide a detailed view to Babesia parasite sexual commitment by monitoring its kinetics upon various stimuli. Moreover, a new direction of anti-babesial therapy is proposed by validation of the Babesia proteasome as a drug target. Overall, the research presented in the thesis extends the current knowledge of the Babesia parasite biology including molecular interactions at the tick-Babesia interface and thereby could significantly contribute to a potential control of babesiosis.
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Insulin analogues with A-chain extended by the D-domain of IGF-1 and IGF-2
Povalová, Anna ; Stiborová, Marie (advisor) ; Dračínská, Helena (referee)
Insulin and insulin-like growth factors (IGF-1 and -2) together with their receptors take part in a complex system, which affects both basal metabolism of carbohydrates, lipids and proteins as well as cell growth, proliferation, differentiation and apoptosis. Defects in action of insulin or IGFs can lead to serious diseases such as diabetes or cancer. Both of these disorders represent nowadays one of the biggest health threats to the world's population. Insulin and IGFs induce different biological effects through their cognate receptors; two isoforms of the insulin receptor (IR-A and IR-B) and the receptor for IGF-1 (IGF-1R). These receptors bind insulin and IGFs with different affinities and induce different but partially overlapping signalling events leading towards metabolic (especially insulin) or mitogenic responses (IGFs and insulin). To understand the mechanism of action of insulin and IGFs it is important to specify which structural domains of these hormones are responsible for binding to the receptors and exerting specific effects. One region that is missing in insulin is the D-domain of IGF-1 and -2. For this reason, we decided to prepare insulin analogues with the A-chain extended by either the whole D-domain of IGF-1 or IGF-2, or by fragments of the IGF-1 D-domain in order to define the...
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Vliv klíštěcích slin na žírné buňky na úrovni signálních drah
HEJDOVÁ, Barbora
Intracellular signalling molecules create the signalling cascades which enable the transfer of the signal to the cell. In this work we have studied the influence of tick saliva on the cytokine production and the activation of signalling pathways in ionomycin stimulated murine mast cells. We found out that tick saliva inhibits production of several cytokines and affects two important signalling pathways in mast cells possibly involved in the regulation of cytokine induction.
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