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Nanoforms of cabozantinib - preparation and characterisation
Fürbacherová, Pavlína ; Indra, Radek (advisor) ; Mrízová, Iveta (referee)
Cancer diseases belong among most serious problems of modern medicine, after cardiovascular problems. In connection with finding the solution of this problem, in recent years there was a development of so-called targeted therapy, which uses nanoparticles in the treatment, which are supposed to make the treatment more effective. One of nanoparticles used in the targeted therapy, is apoferritin, which is naturally occurring transport and storage protein in the human body. Apoferritin has a cavity in its structure, into which a cytostatic agent can be incorporated. In addition, its structure is strongly dependent on the pH value, which makes the incorporation and the subsequent release of the drug in the desired location easily impressionable. These properties make apoferritin a suitable potential nanotransporter. The drug studied in this thesis is the cytostatic drug called cabozantinib. It's tyrosinkinase inhibitor, used in the treatment of advanced metastatic medullary thyroid carcinoma, hepatocellular carcinoma and refractory renal carcinoma. In this thesis, the preparation of cabozantinib complex incorporated in apoferritin was optimized, and subsequently the release of the drug from apoferritin and the metabolism of this complex were monitored using liver microsomes and cytochromes. The results...
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Modulation of cytochrome P450 activity by the anticancer drug lenvatinib
Ivančík, Martin ; Dračínská, Helena (advisor) ; Mrízová, Iveta (referee)
Lenvatinib, commercially marketed as Lenvima®, is an oral drug approved for the treatment of thyroid cancer, hepatocellular carcinoma and renal cell carcinoma that acts as a tyrosine kinase inhibitor. In vitro and in vivo studies have shown that lenvatinib is in the human body metabolised in liver and kidney by the cytochrome P450 enzyme system and aldehyde oxidase. Therefore, the aim of this bachelor thesis was to determine the effect of lenvatinib on the activity of individual isoforms of human cytochrome P450. Among the isoforms studied, those that ensure the metabolism of majority of foreign substances in the human body were selected. Measurements were performed in vitro using recombinant CYPs expressed in SupersomesTM and using marker reactions that are provided by individual cytochrome P450 isoforms. The activity of the enzyme in the reaction mixtures containing lenvatinib was compared with the activity of the enzyme in the reaction mixtures where only the solvent DMSO was added instead of lenvatinib. The concentration of lenvatinib corresponded to the concentration of the given substrate or was 10 times higher. Based on these measurements, the percentage activity of cytochrome P450 isoforms 1A1, 1A2, 1B1, 2B6, 2C8, 2C9, 2E1 and 3A4 in the presence of lenvatinib was calculated. A decrease in...
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Comparison of the determination of hormones (Follicle stimulating hormone, Luteinizing hormone, Prolactin, Testosterone, Progesteron) by two analytical systems. Converting accredited method and its verification.
Kucejová, Soňa ; Martínková, Markéta (advisor) ; Mrízová, Iveta (referee)
Analytical system ARCHITECT i2000SR was verified according to requirements of ÚLBLD VFN and 1. LF UK laboratory in Prague. Repeatability, intermediate precision, and measurement uncertainty were determined as performance parameters for verification of analytical assays for testosterone, progesterone, luteinizing hormone, follicule stimulating hormone and prolactin. Results of Lyphochek control samples, which were measured, were consistent with values given by manufacture. Repeatability: coefficients of variation for testosterone Lyphochek 1 6,81%, for Lyphochek 3 6,40%, progesterone 2,4% and 1,8%, luteinizing hormone 5,38% and 1,89%, follicle stimulating hormone 5,12% and 3,24% prolactin 1,45% a 1,83%. Intermediate precision: coefficients of variation for testosterone Lyphochek 1 6,02%, Lyphochek 2 3,60%, Lyphochek 3 3,07%, progesterone 7,9%, 4,9% and 5,8%, luteinizing hormone 4,50%, 5,51% and 5,83%, follicle stimulating hormone 4,00%, 3,72% and 4,87%, prolactin 4,60%, 4,20% and 5,00%. Measurement uncertainty: testosterone 6,02%, progesterone 7,9%, luteinizing hormone 5,83%, follicle stimulating hormone 4,87%, prolactin 5,00%. Analytical System Architect i2000SR was compared with previously used ADVIA Centaur system to find out, whether it is possible to convert the method Centaur Testosterone,...
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Comparison of adsorption capacity and adsorption efficiency of diosmectite and charcoal on selected compounds that often cause acute intoxication in adult population of the Czech Republic
Mináriková, Michaela ; Martínková, Markéta (advisor) ; Mrízová, Iveta (referee)
In the treatment of acute intoxications, one of the treatment procedures is an antidote submission, e.g. diosmectite and activated charcoal, where an antidote is a substance which acts antagonistically and disturbingly with the toxic effect of a toxic substance. The aim of this work was to compare the adsorption capabilities of activated charcoal and diosmectite in selected model compounds which are the most common originators of acute intoxications in the adult population of the Czech Republic. The actual comparison of adsorption capabilities of these sorbents was preceded by issues search processing of ten groups of substances that cause the most acute intoxications and subsequent testing of the proposed method for future detailed testing of adsorption and adsorption efficiency of different sorbents. Of the ten groups of substances five model compounds were selected: dosulepin, acetylsalicylic acid, ibuprofen, promethazine and phenobarbital, on which adsorption of diosmectite, activated charcoal, and mixture of these sorbents was compared in the experimental part of this work. This comparison of the adsorption capabilities of sorbents was carried out not only under neutral conditions, but also in an alkaline and acidic environment which simulated physiological conditions in different parts of the...
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The mechanism of action of anticancer drug ellipticin in target tissues of its effect
Mrízová, Iveta
Ellipticine is an alkaloid isolated from Apocynaceae plants exhibiting significant antitumor and anti-HIV activities. Cytochromes P450 (CYP) and peroxidases are the enzymes participating in metabolism of ellipticine. This process provides activation and detoxication metabolites of ellipticine. The CYP enzymes, which participate in oxidation of ellipticine in different tissues (liver, lung and kidney) of rat, a model organism simulating the fate of ellipticine in humans have already been identified. In this work, the effects of ellipticine on contents and catalytic activities of CYPs and other components of the mixed-function oxidase (MFO) system in this animal system were studied. For detection of contents of CYPs and other components of the MFO system, spectroscopic and electrochemical methods were used. To determine catalytic activities of CYPs and NADPH:cytochrome P450 reductase, reactions with specific substrates of these enzymes were utilized. The results found in this study demonstrate that expression and catalytic activity of CYP1A is induced by ellipticine in all of the tested organs (liver, kidney and lung) of rats treated with the drug. Moreover in liver, the cytochrome b5 expression is also induced. In addition, in this organ, expression and catalytic activity of CYP3A was increased by...
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The effect of NADPH:cytochrome P450 reductase and cytochrome b5 on metabolism of vandetanib by cytochrome P450 3A5
Škriabová, Simona ; Indra, Radek (advisor) ; Mrízová, Iveta (referee)
There are several ways for cancer treatment. One of them is chemotherapy, when cancer patients are given a cytostatic or a combination of multiple types of drugs. The aim of this bachelor thesis was to study the metabolism of the anticancer drug vandetanib. Vandetanib is a tyrosine kinase inhibitor, that has been used in Europe since 2012 for treatment of symptomatic or progressive medullary thyroid cancer. The kinetics of vandetanib oxidation by cytochromes P450 3A5 was studied in this thesis. Oxidation was investigated by two different systems. The first were recombinant cytochromes P450 3A5 expressed in baculovirus-transfected insect cells (SupersomesTM ) and the second were human recombinant cytochromes P450 3A5 expressed in E.coli cells (Bactosomes). Furthermore, the effect of NADPH:CYP reductase and cytochrome b5 on vandetanib oxidation was investigated. Both systems formed the demethylated metabolite of vandetanib, N-desmethylvandetanib, which was separated by HPLC. The study of enzyme kinetics of vandetanib oxidation by human CYP3A5R, 3A5BR, 3A5BLR in Bactosomes indicates that two vandetanib molecules can bind into the active site of the enzyme, resulting in more efficient oxidation. The results also indicate that not only NADPH: CYP reductase, but also cytochrome b5 affects vandetanib...
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Metabolism of tyrosine kinase inhibitor cabozantinib by rat liver microsomes
Jurečka, Tomáš ; Indra, Radek (advisor) ; Mrízová, Iveta (referee)
Cabozantinib is an anticancer drug that was approved for treatment of progressive thyroid cancer by FDA and EMA organizations. Cabozantinib is a tyrosine kinase inhibitor. It blocks signal pathway receptors that are important for growth of tumors. This bachelor's thesis describes the findings about the metabolism of cabozantinib. It studies metabolism of cabozantinib in hepatic microsomes isolated from various laboratory animals (rat, mouse and rabbit) and impact of particular isoforms of cytochromes P450 (CYP) on metabolism of cabozantinib in rat hepatic microsomes. The bachelor's thesis also describes the optimization of method for separation metabolites of cabozantinib by high performance liquid chromatography (HPLC) and also identification of metabolites using mass spectrometry. Up to three different metabolites were detected by utilizing hepatic microsomes isolated from various laboratory animals. Those were M1, monohydroxycabozantinib and O-desmethylcabozantinib. Mouse microsomes oxidized cabozantinib mainly to O-desmethylcabozantinib and rabbit microsomes metabolised cabozantinib mainly to monohydroxycabozantinib. Microsomes from controlled rats produced two metabolites with the overall majority of monohydroxycabozantinib. The highest number of metabolites was produced by microsomes from...
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Study of the mechanism of anticancer drug action on neuroblastomas
Černá, Tereza ; Stiborová, Marie (advisor) ; Souček, Pavel (referee) ; Mrízová, Iveta (referee)
Despite advances in cancer diagnosis and therapy, cancer is the second leading cause of death globally. The improvements of cancer treatment are the major challenge in this research. The aim of the thesis was studying of effects of two anticancer drugs ellipticine (Elli) and doxorubicin (DOX) on some cancer and healthy cell lines. Specific consideration was given to expand current knowledge about the metabolism and cytostatic effects of Elli in neuroblastoma cell lines. Another part of this study was focused on mechanisms contributing to the development of ellipticine-resistance in cancer cells and influence of histone deacetylase inhibitors on anticancer therapy was investigated. Moreover, the aim was to develop apoferritin (Apo) nanocarrier suitable for the active transport of cytostatics to cancer cells. Several essential data were found in this doctoral thesis. Anticancer efficiency of Elli depends on the CYP3A4-mediated metabolism in cancer. The CYP3A4 enzyme encapsulated into two nanoparticle forms, liposomes and SupersomesTM , was tested to activate ellipticine to its reactive species forming covalent DNA adducts. The formation of adducts seems to be dependent on concentrations of CYP3A4 in nanoparticle systems. A higher effectiveness of CYP3A4 in SupersomesTM than in liposomes to form...
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The role of mixed function oxidases system with cytochrome P450 in metabolism of drugs and carcinogens
Mrízová, Iveta ; Stiborová, Marie (advisor) ; Levová, Kateřina (referee) ; Hansíková, Hana (referee)
6 Abstract Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), an alkaloid isolated from Apocynaceae plants, exhibits significant antitumor and HIV activity. This antitumor agent binds to DNA and forms covalent DNA adducts. Enzymes, which are involved in its enzymatic activation, are cytochromes P450 (CYP) and peroxidases. To elucidate the effect of ellipticine on the expression and enzymatic activity of the individual components of the microsomal mixed function oxidase system in different tissues, we used rat model. Simultaneously, the effect of ellipticine and its cytotoxicity on different tumor cell lines was also investigated. Another part of the presented work was targeted on preparation of anti-peptide antibody against orphan cytochrome P450 2S1, which is highly expressed in many human tumours of the epithelial origin, for its detection in these tissues. For better understanding how CYP2S1 can contribute to the metabolism of xenobiotics, the protein was prepared by heterologous expression in E. coli. Furher, its role in metabolism of an antitumor drug ellipticine, a carcinogenic environmental pollutant benzo[a]pyrene (BaP) and its derivate BaP-7,8-dihydrodiol was examined. Utilizing a mouse model, the impact of pulmonary inflammation on the metabolism of an environmental carcinogen was...
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Study of effect of flavonoids on biotransformation enzymes expression
Koucká, Kamila ; Moserová, Michaela (advisor) ; Mrízová, Iveta (referee)
Flavonoids belong to the group of phenolic compounds included in the secondary metabolites of plants, which are represented mainly in fruits and vegetables. These compounds have antioxidant and anti-carcinogenic effects. Some of them can affect biotransformation enzymes, which include the cytochrome P450 and can interfere with the metabolism of xenobiotics. In the present work we studied effect of dihydromyricetine on the gene expression of cytochrome P450 1A1, 1A2 and cytochrome b5 in livers, lungs, kidneys, colon and small intestine of laboratory rats. The small intestine was divided into three parts namely a proximal, middle and distal. At first, isolation of total RNA was made using commercial reagents and isolated RNA was converted to cDNA by reverse transcription. Finally, using polymerase chain reaction in real time (RT-PCR), the relatively gene expression of genes observed in the organs of laboratory rats pretreated dihydromyricetine and control laboratory rats (untreated) to a reference gene β-actin was determined. It was found that dihydromyricetine did not significantly affect the gene expression of studied genes in most organs. However, a significant decrease of gene expression of CYP1A1 and CYP1A2 was observed in the lungs. On the contrary, an increase of gene expression of CYP1A2 was...
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