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Effect of the anticancer drug cabozantinib on cytochrome P450 activity
Slobodníková, Eva ; Dračínská, Helena (advisor) ; Václavíková, Radka (referee)
Cabozantinib is an anti-cancer drug used mainly for the treatment of thyroid and renal cell carcinoma. It is classified as a low molecular weight selective tyrosine kinase inhibitor. Tyrosine kinases play a key role in signal transduction and regulation of many cellular processes such as growth, differentiation, and proliferation. The changes in the tyrosine kinase pathways are associated with the formation and progression of tumors where their growth is uncontrolled. Tyrosine kinase inhibitors act on tyrosine kinase receptors, thereby preventing the spread of cancer cells and slowing down the progression of cancer. Because cabozantinib, like other clinically used drugs, is metabolized by cytochromes P450, adverse drug interactions may occur that result in altered pharmacokinetics of the administered drugs and a consequent decrease in the efficacy of these drugs. In this diploma thesis, the effect of cabozantinib on the activity of the main enzymes of phase I biotransformation of xenobiotics, cytochromes P450, was investigated in vitro. The effect on the activity of both rat and human cytochrome P450 isoforms involved in xenobiotic metabolism was studied. CYP isoforms were predominantly incubated with cabozantinib at two concentrations; 10 µM and a concentration corresponding to the substrate...
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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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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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The effect of antitumor agents on the expression and activity of cytochrome P450 subfamily 2C
Uher, Tomáš ; Dračínská, Helena (advisor) ; Feglarová, Tereza (referee)
Targeted therapies, acting by blocking essential biochemical pathways required for tumor cell growth and survival, are being used lately in multiple cases of cancer treatment. Cabozantinib, a small molecule inhibitor of receptor tyrosine kinases, is an example of a targeted drug, regulating growth, angiogenesis and metastatic pro- gression of medullary thyroid cancer. Such drugs are also often complemented by cytotoxic agents, e.g. ellipticine; however, therapeutic usage of ellipticine itself is limited due to its poor solutibility and variety of adverse effects. In this bachelor thesis, effects of cabozantinib, ellipticine, or their combina- tion on gene and protein expression of cytochromes P450 2C6 and 2C11 have been studied in vivo. Aforementioned cytochromes have an important role in biotrans- formation of xenobiotics in rat liver. Their protein expression has been assessed by Western blot immunoassay technique, while the gene expression was evaluated by quantitative PCR method. Furthermore, the effects of studied substances and their combination on CYP2C6 and CYP2C11 specific activity have been determined by diclofenac 4'-hydroxylation and testosterone 16α-hydroxylation, respectively. Additionally, direct inhibitory effect of cabozantinib on recombinant CYP2C11 rat isoform has been studied in...
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Effect of tyrosine kinase inhibitor cabozantinib and cytotoxic alkaloid ellipticine on expression and activity of cytochromes P450 1A1, 1A2 and 1B1
Měkotová, Barbora ; Dračínská, Helena (advisor) ; Jeřábek, Petr (referee)
In recent years, tyrosine kinase inhibitors have been more and more used for the targeted cancer therapy, due to their ability to disrupt intracellular signalling pathways associated with the development of tumours. Cabozantinib is the tyrosine kinase inhibitor which has been approved for the treatment of thyroid cancer and it is also effective against several other types of cancer. However, multiple drugs combination is often used in anticancer therapy, which may result in their cytochrome P450-mediated interactions. Although this may affect the therapeutic effect of the drugs and cause adverse effects on the organism, very little is known about the effect of cabozantinib on biotransformation enzymes. Therefore, the effect of cabozantinib not only alone but also in combination with the known cytostatic ellipticine on the expression and the activity of cytochromes P450 1A1, 1A2 and 1B1 in rat liver and kidney in vivo was studied in this work. The gene expression was determined by quantitative PCR, the amount of protein was studied by Western blotting and consecutive immunodetection. The enzyme activity was studied using specific marker reactions, 7-ethoxyresorufin O-deethylation for CYP1A1, 7-methoxyresorufin O-demethylation for CYP1A2 and 17β-estradiol 4-hydroxylation for CYP1B1. Our results...
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Study of action of anticancer drugs tyrosine kinase inhibitors in a form of nanotransporters
Takácsová, Paulína ; Stiborová, Marie (advisor) ; Černá, Tereza (referee)
Tyrosine kinase inhibitors (TKI) are small organic molecules designed for the targeted cancer therapy. They perform the inhibition of activated receptor tyrosine kinases in tumor cells, that defeats tumor growth, proliferation, metastasis and angiogenesis in tumor tissue. Two TKI, lenvatinib and vandetanib, are used in thyroid cancer treatment. This thesis investigates the ways leading to enhancement of efficiency of these anticancer drugs for therapy. One of the studied anticancer drug - lenvatinib - was investigated to be prepared in a nanoform. Nanoparticles were based on protein apoferritin as well as on lipids. Theoretical model of lenvatinib interaction with an apoferritin cavity, as well as the model of its encapsulation obtained by computer modeling indicated that lenvatinib seems not to be suitable for preparation of apoferritin nanoparticles. Since lenvatinib occurs in its neutral form during preparation of nanoparticles, it does not interact with nanoparticle. The unsuccessful experimental preparation of lenvatinib-loaded apoferritin nanoparticles confirmed that lenvatinib is not suitable for its preparation. However, the theoretical model can serve for screening of other potentially suitable drugs before the experimental nanoparticle preparation. Since the experimental preparation of...
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The effect of tyrosinkinase inhibitors vandetanib and lenvatinib and cytotoxic alkaloid ellipticine on biotransformation enzymes
Baráčková, Petra ; Dračínská, Helena (advisor) ; Václavíková, Radka (referee)
In recent years, tyrosine kinase inhibitors have been widely used for the treatment of certain tumors as so-called targeted therapy. Many studies are concerned with their metabolism and the role of enzymes in the biotransformation process, but very little is known about the impact of tyrosine kinase inhibitors on the expression and activity of biotransformation enzymes. Nevertheless modification of the expression and activity of enzymes may cause adverse interactions of co-administered drugs and their negative impact on the human body. This diploma thesis studies the effect of tyrosine kinase inhibitors vandetanib and lenvatinib and cytotoxic alkaloid ellipticine on biotransformation enzymes in a rat model organism in vivo. The aim was to characterize the effect of the investigated compounds on gene expression, protein expression and activity of cytochromes P450 (CYP) 1A1, 1A2 and 1B1 and flavin-containing monooxygenases FMO1 and FMO3 in renal and hepatic microsomes. Microsomes and RNA were isolated from kidneys of control rats and the pretreated rats. Western blot and immunodetection was used to compare the protein expression levels of studied enzymes in kidney and liver. By reverse transcription, cDNA was prepared from isolated RNA and used as a template for quantitative PCR to compare the...
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The inhibitors of tyrosine kinases and their effect on the expression of biotransformation enzymes
Dvořák, Josef ; Dračínská, Helena (advisor) ; Moserová, Michaela (referee)
Tumor diseases are one of the most common causes of death in the human population. One of the many possible causes of tumor growth is abnormal function of tyrosine kinases, which are involved in signal transfer and regulation of the most important cell processes. These processes include the control of cell growth, division and cell differentiation and apoptosis. For the therapy of tumor diseases caused by the abnormal function of tyrosine kinases, their specific inhibitors are developed. For the targeted treatment of thyroid tumors, the tyrosine kinases vandetanib and lenvatinib are newly used. In this bachelor thesis, the effect of vandetanib and lenvatinib on the gene expression of the cytochrome P450 family of 2 (CYP2A2, CYP2B1, CYP2C11, CYP2D1, CYP2E1) biotransformation enzymes has been investigated as they are involved in the biotransformation reactions of a large portion of the available drugs on the market. To examine the relative gene expression of CYP2, quantitative PCR of samples of cDNA, synthesized from isolated RNA from rat liver and kidney exposed to the above-mentioned tyrosine kinase inhibitors, was used. The results suggest, that vandetanib and lenvatinib do not have a significant effect on the gene expression of cytochrome P450 family 2 in rat liver and kidney tissue. KEY WORDS:...
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Metabolism of an inhibitor of tyrosine kinase lenvatinib as the anticancer drug with targeting effects
Vavrová, Katarína ; Stiborová, Marie (advisor) ; Kubíčková, Božena (referee)
Lenvatinib is an oral anticancer drug that belongs to a group of tyrosine kinases, which block signal pathway receptors for development and proliferation of various cancer diseases. Lenvatinib was approved in 2015 for a treatment of progressive, locally spread or metastatic, differentiated thyroid cancer refractory to radioiodine treatment. This thesis presents findings about the metabolism of lenvatinib and identification of enzymes responsible for biotransformation of this drug. Utilizing human and rat hepatic microsomes as well as recombinant cytochromes P450 (CYPs) expressed in SupersomesTM , the metabolism of lenvatinib was studied. Used rat microsomal systems were isolated from the liver of uninduced rats and from the liver of rats in which expression of individual CYPs was induced by CYP inducers. The lenvatinib metabolites were separated by HPLC and identified by mass spectroscopy. Using rat microsomal systems, O-desmethyllenvatinib and lenvatinib N-oxide were produced. The highest amount of these lenvatinib metabolites was produced by microsomes of rats pretreated with pregnenolone carbonitrile that is an inducer of CYP3A. Human hepatic microsomes oxidize lenvatinib to O-desmethyllenvatinib and N-descyklopropyllenvatinib. In the case of rat recombinant CYPs, O-desmethyllenvatinib was...
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The effect of vandetanib, lenvatinib and ellipticine on the expression of rat cytochromes P450 1A and 3A
Jelínková, Sandra ; Dračínská, Helena (advisor) ; Žáková, Lenka (referee)
In recent years, the inhibiition of tyrosine kinases,which may incorrectly regulate some singaling pathway has been used to treat cancer as so-called biological therapy. An example of such inhibitors are vandetanib and lenvatinib. These two substances are used to treat thyroid gland tumors because they affect vascular growth factor receptor or endothelial growth factor receptor that can regulate tumor growth and metastasis. Ellipticine, which has anti-tumor effects on lots of tumor disease, has been investigated in this study together with vandetanib and lenvatinib. In this diploma thesis, the effect of mentioned tyrosine kinase inhibitors, ellipticine and their combinations on gene and protein expression of CYP1A1, 1A2, 3A1 and 3A2 in rat liver in vivo was determined. Protein expression was studied using Western blot method with imunodetection. Gene expression was assessed by quantitative PCR. Moreover, the effect of tested substances and their combinations on CYP1A activity (measured as 7-ethoxyresorufin O-deethylation), CYP1A2 activity (measured as 7-methoxyresorufin O-demethylation), CYP1A1 activity (measured as Sudan I oxidation), CYP3A specific activity (measured as testosteron 6β-hydroxylation) and ellipticine, vandetanib, lenvatinib metabolism was determined. It has been confirmed that...
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