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The preparation and characterization of IGF2 prohormones
Potalitsyn, Pavlo ; Žáková, Lenka (advisor) ; Obšilová, Veronika (referee) ; Hudeček, Jiří (referee)
Insulin-like growth factors 1 and 2 are protein hormones that share similar structural and functional features with insulin. They are commonly abbreviated as IGF1 and IGF2. They play important roles in prenatal development and throughout lifespan. Stimulation of growth of all cell types and significant metabolic effects also belong among their known functions. Dysregulation of their activity or elevated levels were observed in a number of diseases such as diabetes mellitus type 2, cancer, hyperthyroidism, amyotrophic lateral sclerosis, muscle dystrophy, acromegaly, Laron dwarfism and other disorders. Functions of IGF2 are less studied than functions of the other members of the family and even less is known about precursors of IGF2. To address these issues we started with production of IGF2 analogues with enhanced specificity to IR for better understanding the mechanism of receptor activation by IGF2. We produced site-specific analogues modified at sites important for receptor binding. IGF2 analogue with Phe48His mutation is the strongest IGF2-derived binder for IR-A reported ever and it is able to activate IR-A to about 60% of insulin ability. We developed new rapid, robust, and sensitive binding assays for testing of ligands of the receptor for IGF2 (IGF2R). First, we immobilized domain 11 of...
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Molecular requirements of LACTB-induced tumor suppression
Jakoubě, Pavel ; Kečkéšová, Zuzana (advisor) ; Rohlenová, Kateřina (referee)
LACTB is a recently discovered mitochondrial tumour suppressor protein operating in many different types of tissues. Its mechanism-of-action seems to be context dependent as it has been shown to suppress carcinogenesis through the induction of cell cycle arrest, apoptosis, differentiation and suppression of EMT. These processes can be further dependent on alterations of lipid metabolism and interactions with additional tumour suppressors and signalling pathways. LACTB is derived from bacterial penicillin binding proteins, is localized to the mitochondrial intermembrane space and possesses enzymatic activity. It was shown to form filaments, which consist of two intertwined antiparallel chains, suggesting its role in the organisation of mitochondrial intermembrane space. In the first aim of my thesis, I wanted to examine in more detail the molecular requirement for LACTB's filament formation with the specific focus on the role of disulphide bonds in this process. In the second aim of my thesis, I intended to uncover the binding partners of LACTB, which might have a role in the filament formation. Realizing both aims will uncover important requirements for the proper folding and biological activity of LACTB. Key words: LACTB, tumour suppressor, cancer, structure, disulphide bonds, protein interactions
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Danio rerio as a model of serious human diseases
Hason, Martina ; Bartůněk, Petr (advisor) ; Živný, Jan (referee) ; Divoký, Vladimír (referee)
(ENGLISH) Over the last five decades, zebrafish (Danio rerio) has become a useful vertebrate model organism for the field of developmental biology and disease control. Using zebrafish in xenotransplantation studies is becoming more popular and progressed towards drug screening of anti-cancer drugs. Zebrafish are particularly suitable for high-throughput pre-clinical drug screening, due to the small size of embryos and the striking evolutionary conservation of cancer- related pathways between human and zebrafish. The fast, large-scale evaluation of the cancer- drug response in vivo could facilitate progress in personalized cancer therapy. Nevertheless, there is still a lack of methods which would allow for rapid and sensitive evaluation of tumor cell growth to facilitate high-throughput screening of drugs in vivo. In our bioluminescent zebrafish transplantation model, we proposed and validated a new screening platform for pre-clinical drug discovery in zebrafish embryos. In our experiments we used the NanoLuc luciferase, which enabled us to rapidly screen inhibitors of cancer growth in a sensitive and quantitative way with very low background compared to the conventional fluorescence signal. In our screen we evaluated the in vivo drug response of 180 kinase inhibitors in zebrafish embryos...
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The role of caspase-3 in apoptosis
Kolářová, Karolína ; Tlapáková, Tereza (advisor) ; Anděra, Ladislav (referee)
Caspases provide anti-inflammatory, apoptotic and developmental processes in organisms. They are enzymes with a wide range of activities in all cells, and various pathogeneses can occur if their proper function is disturbed. Since the 1990s, caspases have been a topic of interest for scientists, as their direct link to the triggering of apoptotic processes is a promising possibility for the therapy of diseases related to apoptosis, such as cancer, neurodegenerative diseases, but also cardiac ischemia and diabetes. The cascade of apoptotic processes is controlled by the aforementioned caspases, which are located in the caspase cascade. When the cascade is triggered in a cell, it is due to the presence of a "danger" signal, which can be very different. The most well-known triggers of the apoptotic cascade include activated Fas receptor and FasL ligand, cytochrome c present in the cytoplasm, an imbalance of IAPs in the cell, damaged DNA, and many others. Upon receipt of a signal, initiator caspase-2, caspase-8, and caspase-9 are activated, which in turn activate effector caspases-3, caspase-6, and caspase- 7, cleaving many substrates to promote apoptosis. Thus, caspase-3 is the effector enzyme responsible for the actual execution of apoptosis. However, caspase-3 properties are not only apoptotic, it...
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Transcriptomic analysis of Mesocestoides corti
Korená, Lucie ; Leontovyč, Roman (advisor) ; Převorovský, Martin (referee)
Some species of parasites, including helminths, can inhibit carcinogenesis in their hosts. The antitumoral effect has been discovered in the tapeworms Taenia crassiceps and Echinococcus granulosus, which genes associated with cancer regression have been identified. The effect of melanoma suppression has also been observed in tapeworm Mesocestoides corti by the Laboratory of Helminthology, Department of Parasitology, Faculty of Science, Charles University, however the mechanism-of-action, remains unknown. For the upcoming research it was essential to have the complex molecular data such as transcriptome of the developmental stage s of M. corti. This work is focused on the transcriptomic profiling of the tapeworm M. corti and the differential gene expression in two different strains of murine hosts (inbred and outbred) using the RNA-Seq. The main goal was to identify upregulated transcripts in the tapeworms from the murine hosts that could have a potential effect on cancer regression. Differential gene expression analysis was performed, and the results showed that tapeworms in murine hosts (regardless of strain) had more upregulated transcripts than tapeworms cultured in vitro. Analysis of highly upregulated transcripts in the tapeworms that were grown in the murine hosts identified several...
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Metabolism of the mitotic inhibitor BTB-1 by first phase biotransformation enzymes
Vančurová, Kateřina ; Indra, Radek (advisor) ; Martináková, Lenka (referee)
Cancer is still one of the most common deaths in the world and therefore new drugs are needed to be developed to stop or slow down this disease. Recently, there has been a huge expansion in drug development. Cytostatics that are still widely used include a group of mitotic inhibitors aimed at inhibiting mitosis. A representative of a mitotic inhibitor is the small newly discovered molecule BTB-1. This molecule mediates reversible inhibition of the molecular motor Kif18A, which plays an important role in cell division. In the first part of this presented bachelor thesis, a suitable method for the determination of BTB-1 using high performance liquid chromatography was developed and subsequently its sensitivity was verified. Furthermore, a suitable extracting reagent was found. In the second part of the bachelor thesis, the metabolism of BTB-1 was studied by the microsomal system of non-premedicated rats and rats premedicated with various cytochrome P450 inducers. Subsequently, the time dependence of BTB-1 conversion was studied by the microsomal system of premedicated rats. The effect of different concentrations of BTB-1 on its metabolism was also studied using the microsomal system of premedicated rats. Furthermore, the metabolism of this new molecule was studied using cytosolar systems isolated...
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Targeting IRAK4 kinase in autoimmune diseases and cancer
Synáčková, Alžběta ; Dráber, Peter (advisor) ; Brdička, Tomáš (referee)
Immune system provides host protection against invading pathogens. However, aberrant activation can lead to development of autoimmune diseases or cancer. Understanding the mechanisms of inflammation and immune responses is crucial for treatment of such conditions and reestablishing immune balance. Toll-like receptors and interleukin-1 family receptors are a key component of the innate immune system. Their downstream molecules, MyD88 and IRAK4, are essential for receptor signaling as their deficiency causes host susceptibility to infection. On the other hand, overactivation of this pathway was shown to be able to promote autoimmunity and cancer. The main focus of this text will be to summarize current knowledge about the mechanism of IRAK4 signaling and how it can be exploited in the development of therapeutics. Keywords IRAK4, MyD88, Toll-like receptors, IL-1 receptor, cytokines, autoimmunity, cancer
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Role of Exosomes in the Progression, Diagnosis, and Treatment of Brain Tumors
Vaníková, Lucie ; Zíková, Martina (advisor) ; Lacina, Lukáš (referee)
Recent studies have confirmed the importance of extracellular vesicles, particularly exosomes, in the development of brain tumors. Considerable attention has been paid mainly to the influence of exosomes on biological processes in brain tumors. Exosomes mediate intercellular communication in the tumor microenvironment by transporting biomolecules. Most often they transmit various types of ribonucleic acids, specifically microRNAs, which affect the signalling pathways related to tumour growth in target cells. Thus, exosomes play an important role in tumor cell proliferation and differentiation, metastasis, and tumor resistance to chemotherapy or radiation. Due to their small size, exosomes can cross the blood-brain barrier and thus promote tumor progression. The topic of the bachelor thesis is a summary of the current knowledge on the role of exosomes in brain tumor progression, diagnosis and treatment.
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