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Genetic factors responsible for hereditary breast and ovarian cancer development Large rearrangements in BRCA1 and BRCA2 genes
Tichá, Ivana ; Pohlreich, Petr (advisor) ; Souček, Pavel (referee) ; Stiborová, Marie (referee)
2. Summary Background: A greatly increased risk for development of hereditary breast cancer is associated with germline mutations in several susceptibility genes. In this study we analyzed large genomic rearrangements (LGRs) in BRCA1/2 genes and we also focused on the role of CHEK2 and TP53 in tumorigenesis. Methods: A series of 586 high risk patients with breast/ovarian cancer that had previously been tested negatively for small mutations in BRCA1/2 was screened for LGRs by MLPA, LR-PCR and sequencing. Chromosome 17-specific aCGH was used to locate deletion breakpoints in regions flanking the BRCA1 gene. MLPA-analysis was also used to detect two frequently occurring mutations in CHEK2 (c.1100delC and a deletion of 5395 bp). The coding region of the TP53 gene was analyzed by sequencing. Results: We identified 9 different LGRs in the BRCA1 gene in 16 patients. Five alterations (deletion of exons 1-17, 5-10, 13-19, 18-22 and 21-24) were novel. Deletions of exons 1-17, 5-14 and 21-22 were identified repeatedly, and represented population specific (founder) mutations. LGRs accounted for 12.1% (16/132) of all detected pathogenic BRCA1 mutations. No LGRs were found in the BRCA2 gene. Pathogenic mutations in other tested genes were less frequent; 2 were detected in TP53 and 9 in CHEK2. Conclusions: In our...
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Metabolism of and DNA Adduct Formation by Carcinogenic o-Anisidine and its Metabolite N-(2-Methoxyphenyl) hydroxylamine
Naiman, Karel ; Stiborová, Marie (advisor) ; Sofrová, Danuše (referee) ; Befekadu, Asfaw (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE DEPARTMENT OF BIOCHEMISTRY Metabolism of and DNA Adduct Formation by Carcinogenic o-Anisidine and its Metabolite N-(2-Methoxyphenyl)hydroxylamine Summary of Ph.D. Thesis RNDr. Karel Naiman Supervisor: Prof. RNDr. Marie Stiborová, DrSc. PRAGUE 2010 Introduction - 2 - INTRODUCTION Aromatic amines are potent toxic or carcinogenic compounds, presenting a considerable danger to the human population (NTP, 1978; IARC, 1982; Garner et al., 1984). They are widely distributed environmental pollutants found in workplaces (e.g. in chemical industry), in emissions from diesel and gasoline engines and on the surface of ambient air particulate matter (NTP, 1978; IARC, 1982), where they add to local and regional pollution (car exhausts, technological spills). Their toxicity and carcinogenicity has been widely examined, but the knowledge in metabolism of several aromatic amines and their physiological effects in humans are still incomplete. This is also the case of o-anisidine. 2-Methoxyaniline (o-anisidine, Fig. 1) is a potent carcinogen, causing tumours of the urinary bladder in both genders of F344 rats and B6C3F1 mice (NTP, 1978; IARC, 1982). The International Agency for Research on Cancer (IARC) has classified o-anisidine as a group 2B carcinogen (IARC, 1982), which is...
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Modulation of metabolic activation of ellipticine by components of the mixed function monooxygenase system
Mrázová, Barbora ; Stiborová, Marie (advisor) ; Tichá, Marie (referee) ; Souček, Pavel (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE, DEPARTMENT OF BIOCHEMISTRY Modulation of metabolic activation of ellipticine by components of the mixed function monooxygenase system Summary of PhD Thesis RNDr. Barbora Mrázová Supervisor: Prof. RNDr. Marie Stiborová, DrSc. Praha 2010 RNDr. Barbora Mrázová Introduction 1 IINNTTRROODDUUCCTTIIOONN Ellipticine (5,11-dimethyl-6H-pyrido [4,3-b] carbazole, figure 1) and its more soluble derivates are alkaloids isolated from Apocyanaceae plants, which exhibit significant antitumor activities[15, 21, 24, 31] . Ellipticine was first isolated in 1959 from the leaves of the evergreen tree Ochrosia elliptica Labil[6] . Nevertheless, its pharmacological efficiencies (and efficiencies of some of its derivates) was found in 1967, when they were prepared by chemical syntheses[7] . Ellipticine and its more soluble derivates, 9-methoxy- ellipticine and 2-methyl-9-hydroxyellipticine in the form of acetate, have been utilized pharmacologically since 1970s. They are highly efficient against osteolytic breast cancer with metastases, acute myeloblastic leukemia, kidney sarcoma and thyroid carcinoma[1, 17, 18, 19, 23] . Ellipticines exhibit also significant anti-HIV activity because of their ability to inhibit retroviral integrase. This is the reason, why ellipticine is also...
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Metabolism of carcinogenic o-nitroanisol and its metabolite o-nitrophenol and two environmental pollutants 2-nitrobenzanthrone and 3-nitrobenzanthrone
Svobodová, Martina ; Stiborová, Marie (advisor) ; Entlicher, Gustav (referee) ; Souček, Pavel (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE DEPARTMENT OF BIOCHEMISTRY Metabolism of carcinogenic o-nitroanisole, its metabolite o-nitrophenol and environmental pollutants 2-nitrobenzanthrone and 3-nitrobenzanthrone Summary of PhD Thesis RNDr. Martina Svobodová Supervisor: Prof. RNDr. Marie Stiborová, DrSc. Prague 2010 RNDr. Martina Svobodová Introduction -1- INTRODUCTION 2-Nitroanisole 2-Nitroanisole (2-methoxynitrobenzene, 2-NA, figure 1) is an important industrial pollutant and a strong carcinogen for rodents causing neoplastic transformation in the urinary bladder and, to a lesser extent, in the spleen, liver and kidney [19, 30, 31] . 2-NA is also a toxic compound, causing anemia. 2-NA is used primarily as a precursor in the synthesis of o-anisidine (2-methoxyaniline), which is an intermediate in the production of many azo dyes. This compound is used in pharmaceutical industry as an intermediate in the synthesis of some medicaments [30, 31] . In spite of potent rodent carcinogenicity of 2-NA, this chemical is weakly mutagenic in the Ames test with the Salmonella typhimurium. This carcinogen also exhibits a low activity in cytogenetic tests. It induces a slight increase in chromosomal aberration and in sister chromatid exchanges, but only at high concentrations [31] . 2-nitroanisole may be...
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Study on metabolism of 3-aminobenzanthrone and induction of biotransformation enzymes
Mizerovská, Jana ; Stiborová, Marie (advisor) ; Mareš, Jaroslav (referee) ; Hýsková, Veronika (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE DEPARTMENT OF BIOCHEMISTRY Study on metabolism of 3-aminobenzanthrone and induction of biotransformation enzymes Summary of PhD Thesis RNDr. Jana Mizerovská Supervisor: Prof. RNDr. Marie Stiborová, DrSc. Prague 2010 RNDr. Jana Mizerovská Introduction 1 INTRODUCTION 3-Nitrobenzanthron, precursor of 3-ABA The nitroaromatic 3-nitrobenzanthrone (3-nitro-7H-benz de anthracen-7-one, 3-NBA) occurs in diesel exhaust and in airborne particulate matter(8, 9, 14) . 3-NBA is most likely formed during the atmospheric reaction of benzanthrone with nitrogen oxides, especially in the presence of ozone, or during imperfect burning of diesel. 3-NBA exhibits extremely high mutagenic activity(9, 14) and is also a genotoxic carcinogen causing lung tumors in rats(14) . 3-NBA is also evaluated to be a potential carcinogen for humans(14, 1, 9, 19) . The genotoxicity of 3-NBA was documented by the detection of specific 3-NBA-derived DNA adducts in vitro, in human cell lines and also in vivo in rats and mice(12, 13, 15, 2) . The predominant DNA adducts formed by 3-NBA after its metabolic activation by reduction of the nitro group are 2-(2'-deoxyguanosin-N2 -yl)-3- aminobenzanthrone and N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone(9, 14) and these are most probably responsible for the...
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Isolation and characterization of catechol 1,2-dioxygenase of Candida tropicalis
Jechová, Jana ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Candida tropicalis yeast is a microorganism that possesses high tolerance for phenol and strong phenol degrading activity. This yeast is capable of utilizing phenol as the sole source of carbon and energy without formation of any secondary waste product. Catechol-1,2- dioxygenase was isolated from cytosolic fraction of this yeast by the procedure consisting of chromatography on DEAE-Sepharose and gel permeation chromatography on Sephadex G- 100. The catechol-1,2-dioxygenase was purified to homogeneity. The enzyme activity was followed by HPLC (catechol consumption and/or cis,cis-muconic acid formation). The activity profiles at different temperatures showed temperature optimum of 30řC. Kinetic characterizations were studying in different values of pH. The values of Km and Vmax of 0,52 mM and 17,2 nM/min for consumption of catechol, respectively, and 0,34 mM and 12,6 nM/min for formation of cis,cis-muconic acid, respectively, were found at optimum pH of the reaction, pH 7,6.
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Enzymes of Candida tropicalis yeast biodegrading phenol
Koubková, Zuzana ; Stiborová, Marie (advisor) ; Turek, Michal (referee)
Effluents of industrial wastewaters from oil refineries, paper mills, dyes, ceramic factories, resins, textiles and plastic contain high concentrations of aromatic compounds, which are toxic to organisms. Degradation of these compounds to tolerant limits before releasing them into the environment is an urgent requirement. Candida tropicalis yeast is an important representative of eucaryotic microorganisms that are able to utilize phenol. During the first phase of phenol biodegradation, cytoplasmatic NADPH-dependent phenol hydroxylase of C. tropicatis oxidizes phenol to catechol. Catechol is in the second phase of biodegradative process oxidized to cis,cis-muconic acid by the reaction catalyzed with catechol-1,2-dioxygenase. In this diploma thesis we investigated the effect of the heavy metal ions on NADPH-dependent phenol hydroxylase and catechol-1,2-dioxygenase of C. tropicalis. Phenol hydroxylase was inhibited by Cu2+ and Pb2+ ions. Catechol dioxygenase was inhibited by all substances containing heavy metal ions (Fe2+ , Mn2+ , Cd2+ , Cu2+ and Pb2+ ), which were tested in this work. The most effective inhibition was produced by Pb2+ followed by Mn2+ , Cd2+ Fe2+ and Cu2+ ions. The higher sensitivity of catechol-1,2-dioxygenase to heavy metal ions might follow from the presence of histidine residue...
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Biochemical and molecular studies of cytochrome c oxidase and ATP synthase deficiencies
Fornůsková, Daniela ; Zeman, Jiří (advisor) ; Hyánek, Josef (referee) ; Stiborová, Marie (referee)
Mgr. Daniela Fornuskova PhD thesis Biochemical and molecular studies of cytochrome c oxidase and ATP synthase deficiencies ABSTRACT The mammalian organism fully depends on the oxidative phosphorylation system (OXPHOS) as the major energy (ATP) producer of the cell. Disturbances of OXPHOS may be caused by mutations in either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). One part of the thesis is focused on the role of early and late assembled nuclear-encoded structural subunits of cytochrome c oxidase (CcO) as well as Oxa1l, the human homologue of the yeast mitochondrial Oxa1 translocase, in the biogenesis and function of the human CcO complex using stable RNA interference of COX4, COX5A, COX6A1 and OXA1L, as well as expression of epitope-tagged Cox6a, Cox7a and Cox7b, in HEK (human embryonic kidney)- 293 cells. Our results indicate that, whereas nuclear- encoded CcO subunits Cox4 and Cox5a are required for the assembly of the functional CcO complex, the Cox6a subunit is required for the overall stability of the holoenzyme. In OXA1L knockdown HEK-293 cells, intriguingly, CcO activity and holoenzyme content were unaffected, although the inactivation of OXA1 in yeast was shown to cause complete absence of CcO activity. In addition, we compared OXPHOS protein deficiency patterns in mitochondria from skeletal...
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Activity of cytochromes P450 1A1, 1A2 and 3A4 expressed in eukaryotic and prokaryotic systems
Indra, Radek ; Stiborová, Marie (advisor) ; Mizerovská, Jana (referee)
Cytochromes P450 (CYP) are a superfamily of heme proteins distributed widely throughout nature, involved in metabolism of a broad variety of substrates and catalyzing a variety of interesting chemical reactions. They play a central role in metabolism of chemotherapeutic agents. Several prodrug antitumor agents have been found as CYP substrates. Ellipticine, an alkaloid found in Apocynaceae plants, is an example of such type of pro-drug. Here, we investigate the efficiencies of human recombinant CYPs expressed in eukaryotic and prokaryotic expression systems, namely in SupersomesTM , microsomes isolated from insect cells transfected with baculovirus construct containing cDNA of human CYP1A1, 1A2 and 3A4 with NADPH:CYP reductase or in Bactosomes, the membrane fraction of E. coli transfected with cDNA of the same human CYP enzymes and NADPH:CYP reductase to oxidize their marker substrates and ellipticine. Cytochrome b5, an aditional component of the mixed function oxidase system, which metabolize xenobiotics was also expressed in some of the systems. The results found in this work demonstrate that human CYP1A1, 1A2 or 3A4 expressed in both eukaryotic and procaryotic systems oxidize their marker substrates (EROD for CYP1A1/2, MROD for CYP1A2 and testosterone 6β-hydroxylation for CYP3A4). They also oxidize...
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Study of transferrin as a marker of congenital disorders of glycosylation
Ondrušková, Nina ; Stiborová, Marie (advisor) ; Befekadu, Asfaw (referee)
Congenital disorders of glycosylation (CDG) represent a heterogeneous group of mul- tisystemic metabolic disorders which are caused by defects in biosynthetic pathways of glycoproteins. The screening test for N-glycosylation disorders is the analyses of sialylated isoforms of serum transferrin (Tf) by means of isoelectric focusing (IEF). Two distinct pathological IEF patterns of Tf are observed. A type I pattern is cha- racterized by a decrease of tetra- and an increase of di- and asialotransferrin, whereas a type II pattern shows in addition an increase of tri- and monosialotransferrin. The aims of diploma thesis were: 1) to evaluate reference range for spectrum of sialylated forms of Tf separated by IEF and 2) to perform biochemical and molecular analyses in three patients (P1-P3) with clinical suspicion for CDG. Serum and genomic DNA from three patients with clinical suspicion for CDG and family members of P1 were analysed. Sera from 99 healthy volunteers within the age range of 2-42 years served as a control group. Tf was analysed by IEF with direct immunofixation, SDS-PAGE and Western blot using specific antibody against human Tf (Dako). Profiles of Tf were quantified by AlphaEaseFC software (Alpha Innotech). Data were analysed by software STATISTICA 9.0 (StatSoft). TF a PMM2 genes were analysed...
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