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Role of selected ABC transporters in breast cancer development
Perglerová, Karolína ; Stiborová, Marie (referee) ; Souček, Pavel (advisor)
Breast cancer is a leading cause of death among women in many countries. In the treatment of the breast cancer cytotoxic drugs (chemotherapy) are often used. Interindividual differences of drug response are an important cause of treatment failures. Bioavailability also depends on a major extent from the expression and activity of drug transport across biomembranes. In particular efflux transporters of the ATP-binding cassette family such as ABCB1, ABCC1 and ABCC2 have been identified as major determinants of chemoresistance in tumor cells. It was hypothesized that variance in the gene expression of membrane transporters and their genetic variance could explain at least in part interindividual differences of pharmacokinetics and clinical outcome of a variety of drugs. This thesis focuses on the functional significance of gene expression of ABCB1, ABCC1 and ABCC2 and single nucleotide polymorphisms in ABCC1 gene.
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The effect of histone deacetylase inhibitor vaplroate on activity and expression of cytochromes P450 and peroxidases oxidizing ellipticine
Göttlicherová, Markéta ; Souček, Pavel (referee) ; Stiborová, Marie (advisor)
Ellipticine is a potent antineoplastic agent, whose mode of action is considered to be based mainly on DNA intercalation and inhibition of topoisomerase II. Ellipticine was also found to form covalent DNA adducts mediated by its enzymatic activation with cytochromes P450 (CYP) and peroxidases. The next study demonstrated increasing formation of these ellipticine-DNA adducts by histone deacetylase inhibitor valproate (VPA) in neuroblastoma cells. This phenomenon correlates with increasing cytotoxicity of ellipticine induced by this histone deacetylase inhibitor. This observation can be explained by several mechanisms. One of them can be loosening the structure of chromatine, which leads to accessing DNA for modification. Another one is the effect of VPA on activities and expression of enzymes metabolizing ellipticine. This study was aimed to test the second hypothesis. Since VPA has been shown to be metabolized by similar enzymes as ellipticine is, we have studied the effect of VPA (i) on oxidation of ellipticine by cytochromes P450 and peroxidases, (ii) on activities of the CYP enzymes, which significantly participate in oxidation of ellipticine (CYP1A, CYP3A) and (iii) on expression of enzymes oxidizing ellipticine (CYP1A1, CYP3A4, lactoperoxidase). Oxidation of ellipticine in vitro by model...
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Synthesis of ellipticine and its pharmacologically more efficient derivative 13-hydroxyellipticine
Hájek, Jan ; Černá, Věra (referee) ; Stiborová, Marie (advisor)
Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole) is plant alcaloid isolated from Ochrosia elliptica1) (Apocyanaceae). Ellipticine's anticancer effect is mainly caused by its intercalation into DNA, formation of covalent adduct with DNA and inhibition of topoisomerase II. Known syntheses of ellipticine are based on chemicals containing two or three aromatic cycles that are used in cyklisation and/or addition reaction to get ellipticine or ellipticine derivates. 13- hydroxyellipticine can be prepared de novo as a product of casual ellipticine synthesis, or as a modification of already synthetised ellipticine. Keywords: ellipticine; synthesis; derivates of ellipticine
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Chemoenzymatic separation of diastereoisomers of silybin
Purchartová, Kateřina ; Wimmer, Zdeněk (referee) ; Stiborová, Marie (advisor)
Silybin is major component of silymarin isolated from seeds of the milk thistle (Silybum marianum). This compound is widely used in human medicine against liver disorders and as a protectant against a number of hepatotoxins. It also exhibits other interesting activities as anticancer and chemoprotective, dermatoprotective and also hypocholesterolemic effects. Natural silybin is a nearly equimolar mixture of two diastereoisomers, silybin A and silybin B, whose analytical separation is quite feasible, but preparative separation is extremely complicated. The aim of this work was to find suitable method leading to separation of both silybin diastereoisomers. A library of hydrolases (lipases, esterases and proteases) was tested for their diastereoisomeric discrimination of the selective alcoholysis of 23-O-acetylsilybins. Novozym 435 (lipase B from Candida antarctica immobilized on acrylic resin) proved to be the most suitable enzyme for the preparative production of both optically pure silybin A and B by enzymatic hydrolysis. Under the optimized conditions, silybin A was obtained in 42 % yield and 97 % purity while silybin B was obtained in 67 % yield and 99 % purity. Covalent modifications of Novozym 435 (acetylation, succinylation, and hydroxyethylamidation), which should lead to improvement of...
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Plant alkaloid sanguinarine and its derivatives
Tůmová, Lucie ; Hýsková, Veronika (referee) ; Stiborová, Marie (advisor)
This work is summarizing actual knowledge about sanguinarine and quaternary benzo[c]fenanthridine alkaloids. The quaternary benzo[c]fenanthridine alkaloids were found in roots plants Sanguinaria canadensis and Macleaya cordata. This plants are used in tradicional Chinese medicine for its antimycotic, antibacterial and anti-inflammatory activities since antiquity. Regarding to possibility quaternary benzo[c]fenanthridine alkaloids to induce apoptosis these investigated such as possible agents for cancer treatment. The quaternary benzo[c]fenanthridine alkaloids interact with DNA and proteins. They are able to intercalate to the DNA. The alkaloids can be used like fluorescence DNA probe. Metabolism by sanguinarine and next quaternary benzo[c]fenanthridine alkaloids has not yet completely determinated. The first step sanguinarine detoxication is its conversion to less toxic dihydrosanguinarine. Sanguinarine oxidation is mediated by cytochrome P450 1A1. Key words: Quaternary benzo[c]fenanthridine alkaloids, sanguinarine, apoptosis, intercalate, heterogenous substances, enzymes, cytochrom P450
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Biochemical properties of quaternary benzo(c)phenanthrene alkaloids
Přenosilová, Lenka ; Naiman, Karel (referee) ; Stiborová, Marie (advisor)
Quaternary benzo(c)phenanthridine alkaloids are plant products found in many plants. The richest sources are mainly Chelidonieae plants and the family Papaveraceae. The basis of the structure of quaternary benzo(c)phenanthridine alkaloids (sanguinarine, chelerythrine, sanguiluthine, sanguirubine, chelirubine, cheliluthine, macarpine) is N- methylbenzo(c)phenanthridine cation. Chemical structure of quaternary benzo(c)phenanthridine alkaloids related to their cytotoxic properties, the ability to intercalation into DNA and the fluorescence capabilities. Quaternary benzo(c)phenanthridine alkaloids occur in two forms, one of which operates reversible equilibrium depending on pH. Very important are the biological effects of quaternary benzo(c)phenanthridine alkaloids. These alkaloids could be used as fluorescent DNA probes and as supravital dye of nucleic acids. Individual quaternary benzo(c)phenanthridine alkaloids have many uses. Sanguinarine is used for its antiplaque and anti-inflammatory effects of oral hygiene. For its effect against the coagulation of blood platelets may play an important role in preventing cardiovascular diseases. Sanguinarine may be used as a potential cytostatic drug for the treatment of cancer. Chelerythrine is similar to use in oral hygiene products and is known for its...
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Mechanism of cancerogenic effect of nitroaromates pollutants in present environment
Čechová, Tereza ; Svobodová, Martina (referee) ; Stiborová, Marie (advisor)
Nitroaromatic compounds are mutagenic and carcinogenic substances present in all environmental compartments. Polycyclic aromatic hydrocarbons react with nitrogen oxides to form nitroaromatics under the conditions that might be expected in polluted air and in combustion processes (fossil fuel combustion, waste heat recovery, metal processing, etc.). Most of nitroaromatic compounds are potent mutagens in bacterial and mammalian systems. They are also carcinogens causing cancer, primarily in the liver, lungs and mammary glands. Nitrobenzanthrones (NBA) are nitroaromatic compounds which were recently found in environmental compartments, especially in the air. 3-Nitrobenzanthrone (3-NBA, 3-nitro-7H-benz [de] anthracene-7-one) is one of the polycyclic aromatic nitro compounds with high toxic effects. 3-NBA is present in environmental pollution, in diesel exhaust and was also detected in soil and in rain water. Bachelor's thesis describes the metabolism of this substance and it also studies its mutagenic and carcinogenic effects. This work also compares the mutagenic and carcinogenic effects of 3-NBA and its derivative, isomer 2-nitrobenzanthrone (2-NBA, 2-nitro-7H-benz [de] anthracene-7-one), which also occurs as a pollutant in air. (In Czech)
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Modulation of activities and expression of enzymes metabolizing ellipticine by histone deacetylase inhibitor trichostatin A
Kopejtková, Barbora ; Kubíčková, Božena (referee) ; Stiborová, Marie (advisor)
Histone deacetylase inhibitor trichostatin A (TSA) increases cytotoxicity of antineoplastic agent ellipticine to human neuroblastoma cells. Its mechanism of action has not yet been explained. One of the possible mode of action is conformational change in chromatin, which leads to changes in DNA that is more accessible to covalent modification and intercalation. The aim of this work is to study another mode of action, which can explain this phenomenon. The question is, if TSA can increase cytotoxicity of ellipticine to human neuroblastoma cells by modulation of activities and expression of cytochromes P450 and peroxidases. These enzymes are responsible for cytotoxicity of ellipticine to human neuroblastoma cells. TSA has no effect on oxidation of ellipticine mediated by cytochromes P450 leading to metabolites responsible for formation of ellipticine-DNA adducts and detoxication metabolites. TSA increases formation of ellipticine dimer, which is a detoxication metabolite, forming during its oxidation by peroxidases. TSA has no effect on activities of CYP1A1, CYP1A2, CYP3A, which significantly participate in oxidation of ellipticine. TSA modulates expression of enzymes oxidizing ellipticin in human neuroblastoma cells. TSA in the presence of ellipticine increases expression of CYP1A1 a CYP3A4 in...
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Study of interaction of antimicrobial peptides with cells in culture
Kroupová, Hilda ; Stiborová, Marie (advisor) ; Votruba, Ivan (referee)
In English The thesis deals with research of novel antimicrobial peptides (AMP) Halictines (HAL-1, GMWSKILGHLIR-NH2 a HAL-2, GKWMSLLKHILK-NH2) and their structural analogs isolated from the venom of the wild bee Halictus sexcinctus. The structure and antimicrobial activity of these peptides had been described earlier [1]. The goal of this diploma thesis is to find peptide which is strongly toxic only for cancer cells and nontoxic for normal cells. Using of the fluorescent marked peptides we aimed to acquire the information about mechanism of action of the studied peptides on the cells. Using the MTT test (determination of valuation IC50), the toxicity of HAL-1 and HAL-2 and their analogs against 2 normal cell lines (Human umbilical vein endothelial cells, HUVEC, and normal rat intestinal cells, IEC) and against 2 cancer cell lines (cancer cells of suppository uterine, HeLa-S3 and cancer cells of human colorectal carcinoma, CRC SW 480) was determined. First we tested antimicrobial peptides with antimicrobial activity and low hemolytic activity. For verification the toxicity of less active analogs was also determined. We found out that the HeLa-S3 cells are the most sensitive to these peptides. The most toxic peptides (HAL-1/9, HAL-1/18, HAL-2/2) kill 50% of cells in the concentration 2,5 - 10 µM. To obtain...
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