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Molecular identification, typing and adaptation of Achromobacter spp. during the course of chronic infection
Učíková, Barbora ; Dřevínek, Pavel (advisor) ; Nemec, Alexandr (referee)
Achromobacter spp. is an emerging pathogen, especially in chronic respiratory infections in patients with cystic fibrosis. MALDI-TOF mass spectrometry provides reliable identification only at the genus level. The nrdA gene sequence is used for species identification of representatives. Clonality studies using multilocus sequence typing can determine whether a patient is still infected with the same clone or whether reinfection with a new strain occurs over time. Time-collected isolates of Achromobacter spp. from patients with cystic fibrosis were included in our study. Patients were divided into three groups according to the time interval between collections. In the first group, the external interval between collections was approximately 10 years, in the second group 7 to 12 months, and the remaining group consisted of single isolates. In the course of chronic infection, Achromobacter spp. adapt to the exposed antibiotics and to the host. Isolates sampled at an interval of 10 years showed a higher number of mutations than isolates with a sampling interval of up to one year. During chronic infection, loss of motility occurs, which we demonstrated phenotypically at the level of motility, reduction in flagella number and changes in flagellar genes. Increased resistance was observed in some isolates by...
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Influence of V-ATPase inhibitors on chemoresistant neuroblastoma lines in vitro
Honzejková, Karolína ; Eckschlager, Tomáš (advisor) ; Martínková, Markéta (referee)
Tumor diseases are one of the most common causes of death worldwide. Despite the great advances in therapy in the last fifty years, this is still a serious health problem. Therefore, great efforts are still concentrated on development of new anti-cancer drugs and therapeutic approaches. Neuroblastoma (NBL) is the most common tumor in infants and the fourth most common in children. Successful treatment is greatly complicated by its heterogeneity. Chemoresistance is an undesirable phenomenon of chemotherapy. One of the chemoresistance mechanisms is the accumulation of weakly basic anticancer drugs in lysosomes. This work deals with the measurement of lysosomal uptake of these compounds in neuroblastoma cell lines UKF-NB-4 and derived, ellipticine-resistant, line (UKF-NB- 4ELLI ) under different conditions. A method for determining the cell lysosomal capacity (volume) by measuring fluorescence intensity of lysosome-specific LTR dye was introduced and the ability of bafilomycin A, a V-ATPase inhibitor, to potentiate the effects of an anticancer agent ellipticine by inhibiting its lysosomal accumulation was investigated. Keywords: neuroblastoma, lysosome, vacuolar ATPase, multidrug resistance
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The Role of Cellular Metabolism in Carcinogenesis. Molecular Pathophysiology of Bladder Cancer Chemoresistance
Kripnerová, Michaela ; Kuncová, Jitka (advisor) ; Nevoral, Jan (referee) ; Chovanec, Miroslav (referee)
Therapeutic resistance of tumours represents an important clinical issue. We can classify the therapeutic tumour resistance in two ways. According to the clinical course, tumours can behave either as primary resistant, i.e. from the very beginning not responsive, or they can display a secondary (also called acquired) resistance, whereby an initial clinical response is lost and the tumour develops into chemo-, radio- or immunoresistant disease. An alternative classification distinguishes cell autonomous resistance mechanisms from resistance that relies on complex interactions within the context of tumour microenvironment. From the research perspective, modelling therapeutic resistance frequently involves experimental treatment of sensitive cancer cells and selection of daughter resistant cell lines. The Ph.D. thesis includes derivation of two unique models of urothelial bladder carcinoma therapeutic resistance. The first model involves newly established urothelial carcinoma cell lines BC44 and BC44DoxoR, which resulted from a prolonged doxorubicin exposure of the mother cell line. The daughter chemoresistant cell line exhibits multidrug resistant phenotype, which extends beyond the selecting drug - doxorubicin - to four additional chemotherapeutic drugs (cisplatin, methotrexate, vinblastine, and...
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Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters
Sýkorová, Martina ; Hofman, Jakub (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Martina Sýkorová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters Tyrosine kinases are an important class of enzymes controlling cell proliferation, carcinogenesis, apoptosis and cell differentiation. Deregulation of these enzymes can transform normal cell into a cancerous one. Blocking their function by tyrosine kinase inhibitors (TKi) is considered a promising treatment for various types of cancer. ATP-binding cassette (ABC) transporters form a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes via ATP-dependent drug efflux pumps. They modulate drug pharmacokinetics, but on the other hand, lead to therapy failure due to overexpression in cancer cells. In our previous study, we evaluated inhibition properties of two selected TKi (alectinib, brivanib) in MDCKII cell lines (parent one and those transduced with human ABCB1, ABCC1 and ABCG2). Alectinib significantly inhibited ABCB1, ABCG2 but not ABCC1 transporter. Brivanib showed triple inhibition of all studied transporters. In the present work, we...
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The Role of Cellular Metabolism in Carcinogenesis. Molecular Pathophysiology of Bladder Cancer Chemoresistance
Kripnerová, Michaela ; Kuncová, Jitka (advisor) ; Nevoral, Jan (referee) ; Chovanec, Miroslav (referee)
Therapeutic resistance of tumours represents an important clinical issue. We can classify the therapeutic tumour resistance in two ways. According to the clinical course, tumours can behave either as primary resistant, i.e. from the very beginning not responsive, or they can display a secondary (also called acquired) resistance, whereby an initial clinical response is lost and the tumour develops into chemo-, radio- or immunoresistant disease. An alternative classification distinguishes cell autonomous resistance mechanisms from resistance that relies on complex interactions within the context of tumour microenvironment. From the research perspective, modelling therapeutic resistance frequently involves experimental treatment of sensitive cancer cells and selection of daughter resistant cell lines. The Ph.D. thesis includes derivation of two unique models of urothelial bladder carcinoma therapeutic resistance. The first model involves newly established urothelial carcinoma cell lines BC44 and BC44DoxoR, which resulted from a prolonged doxorubicin exposure of the mother cell line. The daughter chemoresistant cell line exhibits multidrug resistant phenotype, which extends beyond the selecting drug - doxorubicin - to four additional chemotherapeutic drugs (cisplatin, methotrexate, vinblastine, and...
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Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters
Sýkorová, Martina ; Hofman, Jakub (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Martina Sýkorová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Study on impact of selected tyrosine kinase inhibitors on multidrug resistance mediated by ABC drug efflux transporters Tyrosine kinases are an important class of enzymes controlling cell proliferation, carcinogenesis, apoptosis and cell differentiation. Deregulation of these enzymes can transform normal cell into a cancerous one. Blocking their function by tyrosine kinase inhibitors (TKi) is considered a promising treatment for various types of cancer. ATP-binding cassette (ABC) transporters form a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes via ATP-dependent drug efflux pumps. They modulate drug pharmacokinetics, but on the other hand, lead to therapy failure due to overexpression in cancer cells. In our previous study, we evaluated inhibition properties of two selected TKi (alectinib, brivanib) in MDCKII cell lines (parent one and those transduced with human ABCB1, ABCC1 and ABCG2). Alectinib significantly inhibited ABCB1, ABCG2 but not ABCC1 transporter. Brivanib showed triple inhibition of all studied transporters. In the present work, we...
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Study of ABC drug efflux transporter inhibition by selected tyrosine kinase inhibitors using accumulation methods with cytostatic substrates
Suchá, Simona ; Hofman, Jakub (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Simona Suchá Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Study of ABC drug efflux transporter inhibition by selected tyrosine kinase inhibitors using accumulation methods with cytostatic substrates ATP-binding cassette (ABC) drug efflux transporters are transmembrane proteins that utilize the energy from ATP hydrolysis to drive transport of endogenous and exogenous compounds out of the cell. The overexpression of ABC transporters plays a crucial role in the development of multidrug resistance (MDR), a phenomenon responsible for the failure of chemotherapy. Tyrosine kinase inhibitors (TKI) represent novel beneficial therapeutic approach in cancer treatment. TKI block tyrosine kinases which regulate important cellular processes. Deregulation of these enzymes can lead to various types of cancers. In the present work, we investigated interaction potential of selected TKI (alectinib, brivanib, osimertinib, selumetinib) in MDCKII parent cell line and those transduced with human efflux transporters ABCB1, ABCC1 and ABCG2. Using the accumulation studies, we determined the amount of accumulated model substrates (daunorubicin, mitoxantrone) and evaluated the inhibitory effect of...
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Testování mutací genů v asociasci k některým významným dědičným onemocněním u border kolie
KREJČOVÁ, Lenka
This diploma thesis summarizes knowledge of significant genetically contitioned deseases occurring in border collies. There is described a total of 14 diseases, some with the location of causal mutation not yet known. Primary focus of this thesis is g.4411956_4411960delGTTT mutation of gene VPS13B causing Trapped Neuthrophil Syndrome (TNS), MDR1 gene's mutation AF045016.1: c.227_230delATAG associated with multidrug resistance (MDR1) and CUBN gene's mutation c.8392delC which causes intestinal malabsorption of cobalamin by another name ImerslundGräsbeck syndrome (IGS). A genotype analysis of 89 border collies with a proof of origin was performed. The DNA was extracted from buccal mucosal swabs, the isolation of DNA was performed by Chelex-100 from the native material. The analysis was proceeded by optimized PCR-RFLP method using restrictive MboI (MDR1) and Msl I (IGS) enzymes. There were detected 4 g.4411956_4411960delGTTT mutation vectors causing TNS. As for the MDR1 and IGS there wasn't detected any affected case.
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Evaluation of antiproliferative effect of selected tyrosine kinase inhibitors in MDCKII cell lines
Vagiannis, Dimitrios ; Hofman, Jakub (advisor) ; Čečková, Martina (referee)
4 ABSTRACT Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Dimitrios Vagiannis Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Evaluation of antiproliferative effect of selected tyrosine kinase inhibitors in MDCKII cell lines Tyrosine kinases are important enzymes regulating crucial cellular processes including differentiation, proliferation, apoptosis, transcription, metabolism, and intercellular communication. Deregulation of these enzymes is the cause of various types of cancers. The blockade of their function by tyrosine kinase inhibitors (TKis) is considered a promising approach especially in antitumor pharmacotherapy. ATP-binding cassette (ABC) drug efflux transporters are a family of transmembrane proteins that pump a variety of structurally unrelated compounds out of the cell in an energy-dependent manner. They play an important role in pharmacokinetics (affect absorption, distribution, elimination) and, at the same time, can negatively influence efficacy of chemotherapy (participate in multidrug resistance phenomenon). In our research, we evaluated antiproliferative properties of four selected TKis, namely alectinib, brivanib, osimertinib and selumetinib, in MDCKII cell lines (parent one and those transduced with human...
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Characterization of native and heterologously expressed membrane transporters in yeast using fluorescent probes
Zahumenský, Jakub ; Gášková, Dana (advisor) ; Cebecauer, Marek (referee) ; Krůšek, Jan (referee)
Yeast plasma membrane transporters play crucial roles in many cellular processes, including detoxification and build-up and maintenance of the plasma membrane potential (ΔΨ). The former development of the diS-C3(3) fluorescence assay by the Biophysics Group of the Institute of Physics, Charles University, enabled us to conveniently study both, including their changes, using a simple fluorescent probe diS-C3(3). Many studies carried out on both animal and yeast cells have revealed that ethanol and other alcohols inhibit the functions of various membrane channels, receptors and solute transport proteins, and a direct interaction of alcohols with these membrane proteins has been proposed. Using the diS- C3(3) assay for multidrug-resistance pump inhibitors in a set of isogenic yeast pdr5 and snq2 deletion mutants we found that n-alcohols (from ethanol to hexanol) exhibit an inhibitory effect on both pumps, increasing with the length of the alcohol carbon chain. The inhibition is not connected with loss of plasma membrane structural or functional integrity and is fully reversible. This supports a notion that the inhibitory action does not necessarily involve only changes in the lipid matrix of the membrane but may entail a direct interaction of the alcohols with the pump proteins. Tok1p is a highly specific...
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