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Study of the binding interaction of tyrosine kinase inhibitors with serum albumin
Rodová, Marie ; Indra, Radek (advisor) ; Heidingsfeld, Olga (referee)
Sunitinib and vandetanib are anti-cancer medications prescribed for medullary thyroid cancer (in the case of vandetanib) and for renal cell carcinoma, gastrointestinal stromal tumor, and pancreatic cancer (in the case of sunitinib). They belong to the group of tyrosine kinase inhibitors and act by exhibiting anti-angiogenic effects and by inhibiting tumor cell proliferation and survival through VEGFR. Additionally, vandetanib also inhibits tumor cell survival via EGFR and RET. In the presented thesis, we investigated the binding interaction between serum albumin and the TKIs vandetanib and sunitinib using BSA, HSA, and blood plasma. We examined the differences in interaction between the TKIs and various serum albumins, including pure BSA, pure HSA, and blood plasma, as well as the nature and location of the binding interaction. Additionally, we studied the influence of other ligands on this interaction and the photosensitivity of sunitinib itself. Utilizing spectroscopic techniques, including UV-VIS absorption and fluorescence quenching, we have determined the Stern-Volmer and binding constants, as well as the thermodynamic parameters, for the binding interactions of sunitinib and vandetanib with BSA and HSA. Our results indicate that complex formation occurs between BSA and sunitinib, BSA and...
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Effect of pH and other factors on the metabolic conversion of tyrosine kinase inhibitors.
Čillíková, Olívia ; Indra, Radek (advisor) ; Čermáková, Michaela (referee)
Targeted anti-tumor therapy is a modern and effective approach to cancer treatment. This type of therapy includes several groups of anticancer drugs. The second most commonly used group of targeted chemotherapeutic substances are tyrosinkinase inhibitors. These are small- molecular agents that target specific signalling pathways of the tumor cell, thereby inhibiting it's growth, proliferation and angiogenesis. Representatives of this drug group include vandetanib and sunitinib. Vandetanib is primarily used for the treatment of medullary thyroid cancer and sunitinib has been approved for the treatment of gastrointestinal stromal tumor and advanced renal cell carcinoma. The diploma thesis focuses on the effect of pH and temperature on the in vitro metabolism of vandetanib and sunitinib using first-phase biotrasnformation enzymes. Differently premedicated and control rat liver microsomes were used in the experiments. Human and rat recombinant cytochromes P450 were used for comparison. The primary purpose of the experiments was to find the experimental pH and temperature optimum of the in vitro metabolism of vandetanib and sunitinib. These experiments also investigated the effect of pH and temperature on the drugs themselves and their stability. The effect of pH and temperature on the metabolism of the...
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Effect of rat enzymes on the metabolism of tyrosine kinase inhibitors in vitro and in vivo
Škriabová, Simona ; Indra, Radek (advisor) ; Ptáčková, Renata (referee)
Tyrosine kinase inhibitors are small molecules, orally available, well-tolerated and globally approved drugs for the treatment of several types of tumors. These drugs include vandetanib, cabozantinib, and lenvatinib, which are used to treat thyroid cancer. Vandetanib and cabozantinib are drugs approved for the treatment of medullary thyroid cancer, and lenvatinib is approved for the treatment of differentiated thyroid cancer. In the presented diploma thesis, the in vitro and in vivo metabolism of vandetanib, cabozantinib and lenvatinib was studied. Microsomes isolated from the liver of rats premedicated with pregnenolone carbonitrile were used to study in vitro metabolism. Plasma and urine samples of rats premedicated with individual tyrosine kinase inhibitors were used to study in vivo metabolism. The resulting metabolites were analyzed by high-performance liquid chromatography and subsequently identified using the mass spectrometry method. In the study of in vitro metabolism, when NADPH and cofactors (glucuronic acid and glutathione) were added to the samples, it was found that the most metabolites appeared for all three drugs during a longer incubation periods, and at the same time, it was found that glucuronic acid and glutathione can influence the structure, properties and functions of the...
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Inhibitors of tyrosine kinases as anticancer drugs of a new generation
Hromek, Vlastimil ; Stiborová, Marie (advisor) ; Bárta, František (referee)
At the present time many types of treatment are used for curing of different cancer diseases. Among the most common types of such treatment belong a surgery, radiotherapy, chemotherapy, and immunotherapy. In the case of chemotherapy, there is used a wide (broad) spectrum of chemotherapeutics such as alkylating agents, platinum compounds, antimetabolites, anthracyclines and, at the present time, also inhibitors of tyrosine kinases. The bachelor thesis describes different types of tyrosine kinase inhibitors and their use in treatment of several cancers. They become popular because of their high specifity and minimal side efects. The first successful use of a tyrosine kinase inhibitor was treatment of the patients suffering from chronic myelogenous leukemia (CML) with imatinib. Vandetanib is another inhibitor of tyrosine kinases that is now used for treatment of another cancer, the medullary thyroid cancer. During treatment, vandetanib is biotransformed with cytochromes P450, which are the terminal oxidases of a mixed function oxidase (MFO) system, into the less efficient metabolites. In the practical part of the bachelor thesis we isolated enzymes, which metabolize xenobiotics, including vandetanib. Rat liver tissue was used for isolation of NADPH:cytochrome P450 reductase, which was isolated as a...
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Effect of pH on vandetanib oxidation
Fedák, Michal ; Indra, Radek (advisor) ; Otáhalová, Barbora (referee)
Vandetanib is anticancer drug used mainly for targeted therapy of medullary thyroid carcinoma. It acts as inhibitor of tyrosine kinase and shows selectivity for vascular endothelial growth factor 2 (VEGFR-2) and epidermal growth factor (EGFR). It also inhibits rearranged during transfection (RET) tyrosine kinase activity. Vandetanib is metabolized by cytochromes P450 (CYPs) and flavin-containing monooxygenases (FMOs) in organism of humans as well as experimental animals. CYPs oxidize vandetanib to N-desmethylvandetanib. FMOs are responsible for the formation of vandetanib N-oxide. This bachelor thesis studies effect of pH on vandetanib oxidation by CYPs a FMOs present in rat hepatic microsomes induced by different agents. Collected data show that in majority of series, optimal pH levels for oxidation of vandetanib by CYPs and FMOs are similar to a large extend. The highest amount of N- desmethylvandetanib was observed mostly at the pH 8,5. Vandetanib N-oxide was also produced in the highest quantity at the same level of pH in majority of series. Results suggest that N-desmethylvandetanib is formed at levels of pH which do not fit in interval of pH for optimal CYP activity. This finding is apparently due to a fact that presence of vandeanib in its neutral form, which is effectively oxidized by CYP,...
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Metabolism of vandetanib by cytochrome P450 expressed in prokaryotic systems
Rodová, Marie ; Indra, Radek (advisor) ; Takácsová, Paulína (referee)
1 Abstract Recently, biologically targeted treatment by another name targeted molecular therapies have begun to be used in the treatment of cancers bearing specific molecular genetic or morphological traits. Vandetanib is an oral anticancer drug that belongs to a group of tyrosine kinases inhibitors. These inhibitors block signal pathway receptors, thereby inhibit growth, stimulate cell death and reduce the spread of cancer. Vandetanib was approved in April 2011 by the US FDA for a treatment of progressive or symptomatic medullary thyroid cancer. It is used in patients with metastatic or inoperable locally advanced cancer. The metabolism of vandetanib was studied in this thesis. Specifically, the kinetics of vandetanib oxidation to N-desmethylvandetanib by human recombinant cytochromes P450 3A4 expressed in the membrane of E. coli (Bactosomes). The effect of the presence of cytochrome b5 and the effect of the level of NADPH: cytochrome P450 reductase activity on the activity of cytochrome P450 3A4 were studied. The demethylated metabolite of vandetanib, N-desmethylvandetanib, was identified and separated by high performance liquid chromatography (HPLC). Enzyme kinetics studies indicate that vandetanib oxidation is affected by both, the level of NADPH:CYP reductase activity and the presence of cyt b5....
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Study of effects of tyrosine kinase inhibitors and their metabolites on tumour cell lines
Kolárik, Matúš ; Indra, Radek (advisor) ; Vinklářová, Lucie (referee)
Vandetanib, lenvatinib and cabozantinib are inhibitors of receptor tyrosine kinases approved to treat locally advanced or metastatic thyroid gland, kidney and liver cancers. These multi- kinase inhibitors, inhibit phosphorylation of tyrosine moieties of protein, thus modulate cell signalization in cancer cells. Metabolites of vandetanib, lenvatinib and cabozantinib were detected in vitro as well as in vivo in blood and urine. Cytochromes P450 and flavin monooxygenases were identified as primary enzymes participating in metabolism of these drugs. Literature lacks information regarding pharmacological efficacy of vandetanib, lenvatinib and cabozantinib metabolites. The aim of this diploma thesis was the investigation of pharmacological efficacy of N-oxides of vandetanib, lenvatinib and cabozantinib. The viability measurement under normoxic and hypoxic conditions was employed to determined their efficacy. The expression of enzymes of the first phase of xenobiotics metabolism (CYP 450 1A1, 1B1, 3A4 a CYP 450 oxidoreductase) and receptor tyrosine kinases RET and VEGFR2, as well as mechanism of changes in their expression were investigated using western blotting and flow cytometry. High performance liquid chromatography was utilised to investigate possible metabolism of tyrosine kinase inhibitors and...
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Metabolism of inhibitors of tyrosine kinases, the drugs of new generation
Čillíková, Olívia ; Indra, Radek (advisor) ; Kubíčková, Božena (referee)
Cancer is the second major cause of death after heart-attack in the world. In recent years, research has focused on tyrosine kinase inhibitors (TKIs) as part of targeted chemotherapeutic treatment. Vandetanib is a TKI affecting epidermal growth factor receptor (EGFR), rearrangement during transfection (RET) and vascular endothelial growth factor receptor 2 (VEGFR2). It is primary used for treatment of medullary thyroid cancer. Vandetanib is biotransformed by cytochromes P450 and flavin monooxygenases in human organism. Cytochromes P450 (CYPs) oxidaze vandetanib to only one metabolite, N-desmethyl vandetanib, which exhibits similar efficiency as parental molecule. NADPH is the major cofactor of reaction cycle of CYPs. This bachelor thesis studies the effect of various types of cofactors and pH on oxidation of vandetanib by selected human recombinant cytochromes P450, namely CYP2C8 coexpressed with cyt b5, CYP2D6, CYP3A4 and CYP3A4 coexpressed with cyt b5. Here, we investigate the effect of cofactors NADPH, NADH and their mixture in a 1:1 ratio on the amount of N- desmethyl vandetanib formed during the biotransformation of vandetanib. The effect of pH on the oxidation of vandetanib by CYP 3A4 and CYP 3A4 + b5 was also analysed. We analysed the amount of the metabolite formed at the pH range 7 to 8.5...
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Metabolism of inhibitors of tyrosine kinases, the drugs of new generation
Husák, Ondřej ; Indra, Radek (advisor) ; Černá, Věra (referee)
Vandetanib is orally administrated anti-cancer drug that belongs to the class of tyrosinekinase inhibitors which are used for thyroid cancer treatment. This drug undergoes biotransformation and oxidizes into two metabolites - N desmethyl vandetanib and vandetanib N-oxide. The purpose of this bachelor thesis is to compare the potency of vandetanib to vandetanib N- oxide on neroblastome cell line (UKF-NB-4); the study of metabolic process of vandetanib N- oxid and its effect on vandetanib oxidation. In this bachelor thesis we have confirmed the lower potency of vandetanib N-oxide in comparison to vandetanib. We have also discovered that vandetanib N-oxide undergoes further oxidation into another metabolite via microsomes of phenobarbital treated rats. Data suggest that in the presence of vandetanib N-oxide an increased oxidation of vandetanib to N-desmethyl vandetanib occurs. Further experiments have not confirmed this hypothesis. In higher concentrations of vandetanib, the presence of vandetanib N-oxide did not have any effect on oxidation of vandetanib to N-desmethyl vandetanib. The lower concentration led to inhibition of oxidation of vandetanib.
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Study of tyrosin kinase inhibitor vandetanibe bound in apoferritin and liposomes
Jáklová, Kateřina ; Indra, Radek (advisor) ; Hýsková, Veronika (referee)
5 Abstract In this thesis the anticancer drug vandetanib was studied. Vandetanib is a tyrosine kinase inhibitor affecting signalling of vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR) or RET protooncogene (REarranged during Transfection). It is primarily used for the treatment of advanced tumors of the thyroid gland. Unfortunately, the usage of vandetanib in the cancer treatment is significantly limited by its toxicity and cardiotoxicity (one of the adverse effects is connected with long QT interval). One way, how to minimize these side effects, is binding a drug into a suitable transporter. Apoferritin and liposomes were used as a transport nanoparticles in this study. The aim of this thesis was to study the stability of the complex of nanoparticle apoferritin with vandetanib molecules (ApoVan) and to study the effect of pH on the release of inhibitor from the ApoVan form. Experiments have shown that ApoVan complex is relatively stable after its storage at 4 řC and - 20 řC for up to 8 weeks. Unfortunately after monitoring the effect of pH on the release of vandetanib from ApoVan, it was found that vandetanib is gradually released from its ApoVan form into the neutral environment at pH 7,4 as well as into the acidic environment at pH 6,5 and the way ApoVan is...
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