National Repository of Grey Literature 48 records found  beginprevious24 - 33nextend  jump to record: Search took 0.01 seconds. 
Effects of natural substances on DNA damage and repair capacity in colorectal cell lines
Vodenková, Soňa ; Opattová, Alena ; Čumová, Andrea ; Slíva, D. ; Vodička, Pavel
Colorectal carcinoma)CRC) represents serious ilness with high incidence and mortality worldwide. Generaly, there is a lack of reliable predictive and prognostic biomarkers, implicated late diagnosis. The effectivity of treatment is rather low - about 50%. Main agent used in CRC treatment is 5 fluorouracil (5-FU), alone or in combination with other cytostatics. 5-FU is halogenated pyrimidine, which is or directly incorporated into DNA or disrupts thymidine synthesis in tumour cells. This damage is repaired by base excision repair (BBR) or mismatch repair. The aim of this study is to investigate the effect of 5FU together with extracts of Ganoderma lucidum (GL) and the role of BER in various lines of colorectal cancer cell lines. Results show increased oxidative damage after GL and 5FU+GL treatment and in the same time decrease of DNA repair in colorectal cell lines. This fact could contribute to improve of 5FU efficacy.
IL 57 - Sporadic colorectal cancer: From genetic make-up to complex phenotypic measurement, from risk determination to prognostic markers
Vodička, Pavel ; Slyšková, Jana ; Pardini, B. ; Naccarati, A. ; Souček, P. ; Vodičková, Ludmila ; Vymetálková, Veronika ; Svoboda, Miroslav ; Foersti, A. ; Hemminki, K.
Colorectal carcinogenesis (CRC), is a complex process, resulting in both genomic and chromosomal instabilities. The valid theories of carcinogenesis accent either the role of somatic mutation or the surrounding microenvironment, however neither of them explains all features of cancer. Uncontrolled proliferation and genomic instability point to the DNA damage response and repair as to the key players. In the present study, we will overview several biomarkers in mapping heterogeneous complex CRC disease and providing prognostic information.\nVariants in genes involved in important pathways, such as DNA repair, cell cycle control, folate metabolism and methylation, insulin resistance and obesity, ABC transporters, selenoprotein genes, genes involved in inflammatory/immune response have shown various degree of association with CRC risk. We present also the data on mutations in high risk genes involved in colorectal carcinogenesis. Gene expression levels were determined in relevant pathways and complemented with other important parameters (epigenetic regulators of transcription by methylation). Additionally, the role of post-transcriptional regulation via miRNA or lncRNA was investigated in relation to the risk of CRC and the efficacy of chemotherapy. We have discovered several genetic and epigenetic markers affecting independently the prognosis of CRC. Functional DNA repair tests (complex phenotype) have been implemented as markers of individual susceptibility to sporadic CRC and its prognosis.\nAn application of the whole set of various biomarkers is inevitable to define the phenotypic landscape of the disease and to delineate the individual response to the therapy.\n
Natural compounds and their effect on 5-fluorouracil in colorectal cancer cell lines
Čumová, Andrea ; Opattová, Alena ; Vodenková, Soňa ; Horák, Josef ; Slíva, D. ; Vodička, Pavel
Colorectal cancer (CRC) is the second most common type of cancer and the second most common cause of cancer related deaths in Europe. 5-Fluorouracil (5-FU) is widely used in treatment of various cancers including CRC, but apart from the cytotoxic effect on cancer cells may also cause adverse toxic side effects. 5-FU is an anti-metabolite with chemical structure similar to that of the pyrimidine molecules of DNA and RNA. However, response to chemotherapy is often limited by drug resistance. The p53 protein is one of the most widely studied tumour suppressors and mutations in TP53 gene are frequently detected in different types of tumours. \nGanoderma Lucidum (GLC) is a mushroom used in Traditional Eastern Medicine which exhibits anti-cancer and anti-proliferative effects in vitro\nThe aim of our study is to define the role of p53 in the interaction between 5-FU and GLC extract and their simultaneous effect on survival in CRC cell lines.\nOur results suggest that GLC extract significantly increases cytotoxicity and genotoxicity of 5-FU in CRC lines with different p53 status and may potentially modulate the response of p53 knock-out cells which are less sensitive to 5-FU treatment. Interaction of conventional chemotherapeutics with natural compounds introduces a novel aspect in cancer research and therapy.\n\n
Determination of methylation in the promotor regions of genes, that control metabolism of 5-FU
Bendová, Petra ; Vodička, Pavel (advisor) ; Václavíková, Radka (referee)
Several malignant diseases, such as colorectal, pancreatic, breast or ovarial cancers, are primarily treated with cytostatics 5-fluorouracil (5-FU). 5-FU undergoes biotransformation in human body and arising metabolites induce the damage and subsequent apoptosis in the target cells. The main aim of this diploma Thesis was the determination of methylation in promoter regions of 14 candidate genes participating on 5-FU biotransformation: TK1, PPAT, RRM1, RRM2, UCK2, UCK1, UMPS, TYMP, UPP1, UPP 2 SLC29A1, UPB1, DPYS and DPYD. We hypothesize that the methylation in promoter regions regulates mRNA transcription of the above candidate genes. We have conducted appropriate analyses in 128 colorectal cancer patients, for whom both tumor and nonmalignant adjacent tissues were available. Sample processing and analysis involved DNA isolation, bisulfite conversion of unmethylated cytosines to corresponding uracils, methylation-specific analysis of melting curves with high resolution for theproper methylation analysis and gel electrophoresis to separate PCR products. For the majority of the studied genes (TK1, PPAT, RRM1, RRM2, UCK2, UCK1, UMPS, TYMP, UPP1, SLC29A1 and DPYD) we did not detect any aberrant methylation in promoter regions. In genes DPYS, UPB1 and UPP2 we recorded various degree of promoter...
Posttranslational modification of the adapter protein DAXX in the cellular response to genotoxic stress
Bražina, Jan ; Anděra, Ladislav (advisor) ; Černý, Jan (referee) ; Vodička, Pavel (referee)
Maintaining the chromosome continuity and complete genetic information in human cells is crucial for cell survival and the whole organism. It prevents life-threatening pathologies and preserves genetic continuity. However, cellular DNA is exposed to both endogenous and exogenous stress damaging its content and integrity. This stress activates mechanisms involving detection and repair of these damaged sites (DDR). One of the most serious types of DNA damage double-stranded breaks (DSB) occuring when both strands are severed. DSBs trigger wave of PTMs that regulate protein interactions, nuclear localization and catalytic activity of hundreds of proteins. Such modifications include acetylation, methylation, SUMOylation, ubiquitinylation and especially phosphorylation. The most important kinases involved in DDR kinases are ATM, ATR and DNA-PK. These kinases are activated immediately after the detection of the damaged area. DAXX (Death-associated protein 6) is an adapter and predominantly nuclear protein, which is involved in chromatin remodeling, gene expression modulation, antiviral response and depositing histone H3.3 variants into chromatin or telomeres. Daxx is essential for murine embryogenesis, since the homozygous deletion is lethal in E9.5-10. In 2006 a study mapping the substrates of kinases...
Molecular characteristics of mismatch repair pathway in ovarian cancer
Burócziová, Monika ; Vodička, Pavel (advisor) ; Schierová, Michaela (referee)
In humans, multi enzymatic processes are involved in maintaining DNA stability and cellular homeostasis. Cells undergo several episodes to survive and protect itself in daily basis. Accumulation of DNA errors and breaks are repaired by dynamic machinery, such as mismatch repair (MMR), replication-related process. In presented diploma thesis, we report the studied MMR pathway and its involvement in malignancy of epithelial ovarian cancer (EOC). Our working hypothesis postulated that core genes of MMR, such as MLH1 and MSH2 are down-regulated in malignant cells. Cells therefore become incapable to repair accumulating DNA damage, undergo apoptosis or most likely uncontrolled proliferation. Above mentioned genes may also be silenced in cancer patients at transcription, translation or epigenetic levels. Our aims were to clarify and to investigate the importance of MMR based on mRNA transcription, protein stability and promoter hypermethylation on a set of major MMR genes, particularly MLH1, MSH2, PMS1, MLH3, MSH6, MSH3, and PMS2. In our study, we analysed samples from 63 epithelial ovarian cancer patients and 12 non-malignant reference tissues using RT-qPCR, MS-HRM, and Western Blotting methods. Consequently, our results show down-regulation of all MMR genes except for MSH2 (up-regulated) in tumor...
English royal court and its changes in the context of first half of the 17th century (1603-1640)
Vodička, Pavel ; Soukup, Jaromír (advisor) ; Kovář, Martin (referee) ; Skřivan, Aleš (referee)
The aim of the dissertation is a comparative analysis of the English royal court in the first half of the 17th century. The analytical part of the dissertation focuses on researching processes that influenced the structure and roles in the royal court in regards to the political, religious, economic, social and cultural development of the world. The benchmarks represent the personality of the ruler, institutional structure and personnel composition of the court, its financing and its culture. The comparison is a defined period of time between the beginning of James I (1603) and the end of the personal rule of Charles I (1640). The dissertation is based on critical analysis of the sources and studies of secondary literature. One of the features of the Royal Court during the rule of James I was the rivalry of various factions. In the interest of retaining a balance in power, the monarch revealed selected offices only to members of his Scottish clubs. Targeted strengthening of the influences of selected institutions of court, especially Bedchamber, ended up contributing to a significant weakening of the unitary system of the government, where the Privy Council played a key role up until then. In addition, between 1603 and 1625, there became a strong concentration of power in the hands of the royal...
The application of functional tests to measure DNA repair capacity in molecular epidemiological studies
Slyšková, Jana ; Vodička, Pavel (advisor) ; Hampl, Aleš (referee) ; Kment, Milan (referee)
DNA repair is a vital process of a living organism. Inherited or acquired defects in DNA repair systems and cellular surveillance mechanisms are expected to be important, if not crucial factors in the development of human cancers. DNA repair is a multigene and multifactorial process which is most comprehensively characterized by the phenotypic evaluation of DNA repair capacity (DRC). DRC represents a complex marker with high informative value, as it comprises all genetic, epigenetic and non-genetic factors, by which it is modulated. Accordingly, DRC reflects the actual capability of the cell, tissue or organism to protect its DNA integrity. The present PhD study was focused on investigating DRC, which specifically involves base and nucleotide excision repair pathways, in human populations with different characteristics. The main aim was to answer substantial questions on the possible use of DRC as biomarkers in epidemiological studies. The study was in fact designed to understand the extent of physiological variability of DRC in a population, its modulation by genetic and non-genetic factors, tentative adaptability to high genotoxic stress and, finally, its involvement in cancer aetiology. In order to explore these issues, DRC, in respect to genetic and environmental variability, was investigated...
Vztah mezi genetickými polymorfismy DNA reparačních genů a jejich expresí u zdravé populace (s výhledem na stanovení u onkologických pacientů).
Hánová, Monika ; Vodička, Pavel (advisor) ; Bencko, Vladimír (referee) ; Černá, Marie (referee)
DNA damage response is a complex system responsible for protection of a cell against internal and external DNA damaging agents and in maintaining genome integrity. Many of genes participating in DNA damage response pathways are polymorphic. Genetic polymorphisms in coding and regulatory regions may have impact on the function of proteins encoded by the genes. Phenotypic effect of single nucleotide polymorphisms (SNPs) is subject of investigation in connection with the ability of a cell to manage genotoxic stress and subsequently, in relation to cancer susceptibility. The aim of this thesis was to evaluate the association between SNPs in DNA repair genes (hOGG1, XRCC1, XPC) and cell cycle genes (TP53, p21CDKN1A , BCL2 and BAX) and their mRNA expression in peripheral blood lymphocytes from individuals occupationally exposed to styrene and control individuals. The aim was extended to analyses of relationships between mRNA expression levels of the above-mentioned genes and markers of exposure to styrene (concentration of styrene in blood and in air), markers of DNA damage (single strand breaks - SSBs, and endonuclease III specific sites - Endo III sites) and the base excision repair (BER) capacity, by means of γ-irradiation specific DNA repair rates and oxidative repair. Study on the group of healthy...
Chromosomal damage and DNA repair capacity in blood lymphocytes as transient markers in carcinogenesis.
Kroupa, Michal ; Vodička, Pavel (advisor) ; Štětina, Rudolf (referee)
Recent knowledge suggests that the onset of cancer is modulated by the interplay of internal and external environmental factors along with numerous gene variants. Structural chromsomal aberrations in peripheral blood lymphocytes are considered as biomarkers of effect of genotoxic carcinogens and reflect elevated risk of cancer. Incomplete or deficient repair of double-strand breaks in DNA underlie chromosomal aberrations and the measurement of cytogenetic alterations may reflect interindividual differences in the response towards the mutagen. In this study the expected deficiences in the DNA repair capacity have been determined in incident oncological patients with breast, colorectal and urogenital cancers. The determination of chromosomal aberrations have been supplemented by the measurement of variants in genes involved in double-strand breaks repair (XRCC3, rs861539; RAD54L, rs1048771). Methodologically, we employed conventional cytogenetic analysis, cytogenetic analysis following the induction of chromocomal damage by bleomycin ("Challenge assay"), TaqMan discrimination analysis for the detection of allelic variants and statistical analyses. By using these methods we did not observe statistically signifiant differences either in chromosomal breaks (p=0,354) or in a percentage of cells with...

National Repository of Grey Literature : 48 records found   beginprevious24 - 33nextend  jump to record:
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19 Vodička, Petr
1 Vodička, Přemysl
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