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Structural characterization of interactions between subunits of the GBAF chromatin remodeling complex
Naušová, Karolína ; Veverka, Václav (advisor) ; Rozbeský, Daniel (referee)
Epigenetics investigates heritable phenotypic changes that are not caused by alterations in DNA sequence. One of the major epigenetic tools is chromatin remodeling mediated by ATP-dependent chromatin remodeling complexes, which fundamentally affect gene expression and thus cellular fate. A mammalian variant of the ATP-dependent chromatin remodeling SWI/SNF complex is the BAF complex, which is involved in both activation and repression of gene expression. There have been identified three major variants of BAF complex one of which is non-canonical BAF, also known as GLTSCR1 containing BAF, GBAF. Each complex consists of up to 15 subunits, some of which are specific only to one of the complex variants. Mutations in genes coding subunits of BAF lead to several genetic disorders or to the cancer development. The GBAF complex contains specific subunits, BRD9 (Bromodomain containing protein 9), GLTSCR1 (Glioma tumor suppressor candidate region 1) and GLTSCR1L (GLTSCR1-like), which are essential for its formation. Although the exact function of the GBAF complex has not been elucidated yet, it is often associated with synovial sarcoma and rhabdoid tumors. Two of the three complexes are impaired in those tumors and gene expression is maintained only due to the GBAF complex. If GBAF would additionally loose...
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Investigating critical mechanisms of oncogenesis using cell model systems
Hušková, Hana ; Stopka, Tomáš (advisor) ; Macůrek, Libor (referee) ; Vojtěšek, Bořivoj (referee)
(EN) Humans and cells in their bodies are exposed to various mutagens in their lifetime that cause DNA damage and mutations, which affect the biology and physiology of the target cell, and can lead to the expansion of an immortalized cell clone. Genome-wide massively parallel sequencing allows the identification of DNA mutations in the coding sequences (whole exome sequencing, WES), or even the entire genome of a tumour. Mutational signatures of individual mutagenic processes can be extracted from these data, as well as mutations in genes potentially important for cancer development ('cancer drivers', as opposed to 'passengers', which do not confer a comparative growth advantage to a cell clone). Many known mutational signatures do not yet have an attributed cause; and many known mutagens do not have an attributed signature. Similarly, it is estimated that many cancer driver genes remain to be identified. This Thesis proposes a system based on immortalization of mouse embryonic fibroblasts (MEF) upon mutagen treatment for modelling of mutational signatures and identification and testing of cancer driver genes and mutations. The signatures extracted from WES data of 25 immortalized MEF cell lines, which arose upon treatment with a variety of mutagens, showed that the assay recapitulates the...
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