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Genetic causes of medullary thyroid carcinoma and Hirschsprung's disease
Václavíková, Eliška
Genetic causes of medullary thyroid carcinoma and Hirschsprung's disease Abstract Medullary thyroid carcinoma (MTC) and Hirschsprung's disease (HSCR) are classified as simple neurocristopathies, i.e. diseases linked to neural crest-derived cells. MTC is derived from parafollicular cells of the thyroid and HSCR is characterized by absence of enteric ganglia in the gastrointestinal tract. The RET proto-oncogene is only expressed in neural crest-derived cells, including parafollicular cells and enteric neurons. The RET encodes a transmembrane tyrosinekinase receptor that plays an important role during proliferation, differentiation and cell survival, and activates many signaling pathways. If the strictly regulated activation fails, e.g. due to mutations in the specific gene locations, the RET becomes a highly effective oncogene. Activating germline mutations in the RET proto- oncogene lead to hereditary forms of MTC, whereas sporadic forms of MTC are caused by somatic mutations in the tumor tissue. On the contrary, inactivating mutations induce migration failure of ganglion cell precursors during the development of enteric nervous system and result in the development of HSCR. In rare cases, the coexistence of both diseases is caused by mutations with a dual gain-of-function and loss-of-function character....
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Analysis of hereditary genetic variants predisposing to the development of familial forms of ovarian cancer.
Lhotová, Klára ; Soukupová, Jana (advisor) ; Mohelníková Duchoňová, Beatrice (referee) ; Weinberger, Vít (referee)
Ovarian cancer (OC) is the deadliest gynecologic malignancy with a substantial proportion of hereditary cases and a frequent association with breast cancer (BC). Genetic testing facilitates preventive management for carriers of mutations in OC-susceptibility genes. However, the prevalence of germline mutations varies among populations and many rarely mutated OC predisposition genes remain to be identified. We analyzed 219 genes in 1333 Czech OC patients and 2278 population-matched controls (PMC) using next-generation sequencing. Altogether, 427/1333 (32%) patients and 58 /2278 (2,5%) PMC carried pathogenic mutations in 18 known/anticipated OC predisposition genes. Mutations in BRCA1, BRCA2, RAD51C, RAD51D, BARD1 and mismatch repair genes conferred a high OC risk (with OR>5). Mutations in BRIP1 and NBN were associated with moderate risk (both OR ≥2 - <5). BRCA1/2 mutations dominated in almost all clinicopathological subgroups including sporadic borderline tumors of ovary (BTO). Analysis of remaining 201 genes revealed somatic mosaics in PPM1D and germline mutations in SHPRH and NAT1 associating with a high/moderate OC risk significantly; however, further studies are warranted to delineate their contribution to OC development in other populations. Results of this study demonstrate the high proportion...
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Molecular genetic analysis of patients with Usher syndrome
Průšová, Kateřina ; Ďuďáková, Ľubica (advisor) ; Kousal, Bohdan (referee)
The work focuses on molecular genetic testing of patients with Usher syndrome to confirm the diagnosis, to determine the causal cause of the disease and describe new mutations causing Usher syndrome in Czech patients. Usher syndrome is a clinically and genetically heterogeneous disease that is the most common cause of hereditary deafblindness. Based on responsible genes and disease onset is classified into three clinical subtypes. Given the fact that there is currently no specific treatment, there is a need to understand the pathophysiology of this disease and to broaden the spectrum of causal mutations. The theoretical part of the thesis deals with the anatomy of the eye, especially the structure of the retina. Attention is also paid to retinal diseases, such as the progressive loss of vision characteristic for retinitis pigmentosa (RP). RP may occur either as an isolated disorder or also affecting other organs, so-called syndromic RP. Classic syndromic RP includes Usher's syndrome, which the work mainly deals with. The theoretical part of the thesis describes mainly the mechanism of the disease, the functions of individual Usher proteins and the genes that encode these proteins. The haplotype analysis has been previously done for the most common mutations causing Usher's syndrome in Europe Based...
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Prediction of the Effect of Mutation on Protein Solubility
Velecký, Jan ; Martínek, Tomáš (referee) ; Hon, Jiří (advisor)
The goal of the thesis is to create a predictor of the effect of a mutation on protein solubility given its initial 3D structure. Protein solubility prediction is a bioinformatics problem which is still considered unsolved. Especially a prediction using a 3D structure has not gained much attention yet. A relevant knowledge about proteins, protein solubility and existing predictors is included in the text. The principle of the designed predictor is inspired by the Surface Patches article and therefore it also aims to validate the results achieved by its authors. The designed tool uses changes of positive regions of the electric potential above the protein's surface to make a prediction. The tool has been successfully implemented and series of computationally expensive experiments have been performed. It was shown that the electric potential, hence the predictor itself too, can be successfully used just for a limited set of proteins. On top of that, the method used in the article correlates with a much simpler variable - the protein's net charge.
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Prediction of the Effect of Mutation on Protein Solubility
Marko, Július ; Smatana, Stanislav (referee) ; Hon, Jiří (advisor)
Protein solubility is a key problem in production of functional proteins. Prediction of the effect of mutation on protein solubility could save a lot of time and money, as it would provide in silico prediction of solubility enhancing mutations before performing deep mutational scanning in laboratory. In this work, new predictor of the effect of mutation on protein solubility SoluProtMut is introduced that is based on machine learning methods. Most of the existing predictors predict the effect from the amino acid sequence. In addition to the sequence, the tool presented in this work also uses the spatial structure of the protein, which can significantly increase it's accuracy.
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Possibilities of ex situ protection of rare and endangered plant species
Vítová, Jana ; Münzbergová, Zuzana (advisor) ; Dostálek, Tomáš (referee)
The aim of the bachelor's thesis is to present the possibilities, significance and possible problems of ex-situ protection for the future conservation of biodiversity of plants on Earth. In the introductory part of the thesis, the individual processes and programs of ex situ protection are described, with the help of literature search. At the same time, information on international cooperation in the field of seed banks and botanical gardens is presented, which, through their activities and mutual cooperation, create rescue programs to secure as many samples of plant material for possible future use. The work also mentions international plant databases, which provide the accurate and detailed information about the preserved material of rare and endangered plant species for the public. Further in the thesis, the currently known problems of ex situ protection with their impacts on the collected and stored material are mapped. Keywords Ex situ conservation, threatened plants, Ministry of the Environment, database, seed dormancy, inbreeding, outbreed depression, cultivation, seed bank, botanical gardens, tissue cultures, in vitro, genetic drift, mutation, hybridization, wildlife conservation, endangered species, threatened species
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Clinicopathological and molecular biologic characteristics of selected cutaneous epithelial and nonepithelial tumors
Kastnerova, Liubov ; Kazakov, Dmitry (advisor) ; Šíma, Radek (referee) ; Feit, Josef (referee)
The doctoral thesis MD. Liubov Kastnerova (previous name Kyrpychova) is focused on the histomorphological and molecular biologic features of selected cutaneous epithelial and nonepithelial tumors and is structured as a commentary to the 20 articles published during four years, representing the completed scientific projects in the Ph.D. course. In eight papers, the author of the thesis is the first author, whereas she coauthored in the remaining 12 papers. The thesis is composed of the commented files of authors own publications and it is divided into cutaneous epithelial and nonepithelial tumors. The first section, «Cutaneous epithelial tumors», includes 14 articles that are subdivided into two parts: adnexal tumors (9 articles) and lesions of anogenital mammary-like glands (5 articles). Of the nine articles on adnexal tumors, there are 5 articles focused on various benign and malignant adnexal lesions with apocrine or eccrine differentiation. Novel findings in this part include the identification of hitherto unreported alterations of the MYBL1 gene in adenoid cystic carcinoma of the skin and lack of deletion of the 1p36 locus in this neoplasm; the lack of a correlation between cellular composition and the presence CRTC1-MAML2 fusions in hidradenoma, the absence of CRTC3-MAML2 fusions in this tumor,...
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Genomic instability in patient tumors due to excesive AID activity
Vaníčková, Karolína ; Drbal, Karel (advisor) ; Macůrek, Libor (referee)
AID is a member of APOBEC family of mutational enzymes. AID generates U:G mismatches in ssDNA by deaminating cytosine to uracil. In B cells error-prone repair of these mismatches induces a mutational burden in the process of somatic hypermutation of Ig locus during affinity maturation of immunoglobulins (Ig). AID also induces double-strand breaks during Ig class switch recombination or primary Ig diversification through templated gene conversion in some vertebrate species. AID might gain tumorigenic potential in case of insufficient regulation of induction and repair processes, causing genomic instability and possibly leading to tumorigenesis. AID is induced in epithelial tissues by proinflammatory cytokines via canonical NF-B pathway. Both exogenous factors (pathogens Helicobacter pylori or HCV), endogenous factors (bile acid) or even physiological state such as ovulation are the initiating factors. Thus, AID might be the link between inflammation and carcinogenesis. AID is expressed in different stages of carcinomas, mostly during the initial oncogenic transformation. Mice with ectopic AID expression develop lung, gastric, oral and hepatic carcinomas as well as melanomas. AID also regulates epithelial-mesenchymal transition in other tumors. AID is responsible for treatment resistance in both CML...
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