京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13139号 / 論医博第2139号 / 新制||医||1026(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 松田 道行, 教授 中川 一路, 教授 原田 浩 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Introduction: About 5 - 10% of breast carcinomas are caused by genetic mutations. The most common genetic mutation that is involved in the development of this malignancy is a mutation in the tumor suppressor genes BRCA1/2 whose carriers have approximately a 70% lifetime risk of developing breast cancer. The prognosis of patients with BRCA1/2-asociated breast carcinoma, compared to patients with sporadic breast carcinoma is the subject of many studies with ambiguous results. Aim: The aim of the theoretical part of this work was to approach the issue of breast cancer and the most common genetic syndromes associated with it. In the practical part of this work a retrospective study was carried out in order to compare BRCA1/2 mutated breast cancer patients with non-mutated breast cancer patients in the tumor profile, methods of treatment and prognosis. Methods: We retrospectively analyzed the data of 134 patients who were tested for the presence of BRCA1/2 mutation at the Institute of Medical Genetics, University Hospital in Pilsen during the years 2013-2018 and at the same time were treated for early breast cancer at the University Hospital in Pilsen during the years 2000-2020. 32 patients were BRCA1 positive (24%), 10 BRCA2 positive (7%) and 92 without BRCA1/2 mutation (69%). The follow- up time was...

Indiana University-Purdue University Indianapolis (IUPUI) / The information gained from sequencing of the human genome has begun to transform human biology and genetic medicine. The discovery of functionally important genetic variation lies at the heart of these endeavors, and there has been substantial progress in understanding the common patterns of single-nucleotide polymorphism (SNP) in humans- the most frequent type of variation in humans. Although more than 99% of human DNA sequences are the same across the population, variations in DNA sequence have a major impact on how we humans respond to disease; to environmental entities such as bacteria, viruses, toxins, and chemicals; and drugs and other therapies and thus studying differences between our genomes is vital. This makes SNPs as well other genetic variation data of great value for biomedical research and for developing pharmaceutical products or medical diagnostics. The goal of the project is to link genetic variation data to biological pathways and networks data, and also to clinical data for creating a framework for translational and systems biology studies. The study of the interactions between the components of biological systems and biological pathways has become increasingly important. It is known and accepted by scientists that it as important to study different biological entities as interacting systems, as in isolation. This project has ideas rooted in this thinking aiming at the integration of a genetic variation dataset with biological pathways dataset. Annotating genetic variation data with standardized disease notation is a very difficult yet important endeavor. One of the goals of this research is to identify whether informatics approaches can be applied to automatically annotate genetic variation data with a classification of diseases.

Indiana University-Purdue University Indianapolis (IUPUI) / DNA suffers constant damage, leading to a variety of lesions that require repair. One of the most devastating lesions is a double-strand break (DSB), which results in physical dissociation of two pieces of a chromosome. Necessarily, cells have evolved a number of DSB repair mechanisms. One mechanism of DSB repair is break-induced replication (BIR), which involves invasion of one side of the broken chromosome into a homologous template, followed by copying of the donor molecule through telomeric sequences. BIR is an important cellular process implicated in the restart of collapsed replication forks, as well as in various chromosomal instabilities. Furthermore, BIR uniquely combines processive replication involving a replication fork with DSB repair. This work employs a system in Saccharomyces cerevisiae to investigate genetic control, physical outcomes, and frameshift mutagenesis associated with BIR initiated by a controlled HO-endonuclease break in a chromosome. Mutations in POL32, which encodes a third, non-essential subunit of polymerase delta (Pol delta), as well as RAD9 and RAD24, which participate in the DNA damage checkpoint response, resulted in a BIR defect characterized by decreased BIR repair and increased loss of the broken chromosome. Also, increased incidence of chromosomal fusions determined to be half-crossover (HCO) molecules was confirmed in pol32 and rad24, as well as a rad9rad50S double mutant. HCO formation was also stimulated by addition of a replication-inhibiting drug, methyl-methane sulfonate (MMS), to cells undergoing BIR repair. Based on these data, it is proposed that interruption of BIR after it has initiated is one mechanism of HCO formation. Addition of a frameshift mutation reporter to this system allowed mutagenesis associated with BIR DNA synthesis to be measured. It is demonstrated that BIR DNA synthesis is intrinsically inaccurate over the entire path of the replication fork, as the rate of frameshift mutagenesis during BIR is up to 2800-fold higher than normal replication. Importantly, this high rate of mutagenesis was observed not only close to the DSB where BIR is less stable, but also far from the DSB where the BIR replication fork is fast and stabilized. Pol  proofreading and mismatch repair (MMR) are confirmed to correct BIR errors. Based on these data, it is proposed that a high level of DNA polymerase errors that is not fully compensated by error-correction mechanisms is largely responsible for mutagenesis during BIR. Pif1p, a helicase that is non-essential for DNA replication, and elevated dNTP levels during BIR also contributed to BIR mutagenesis. Taken together, this work characterizes BIR as an essential repair process that also poses risks to a cell, including genome destabilization and hypermutagenesis.

No description available.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer and urgently requires new therapies. Oncolytic viruses (OV) are a strong contender. OVs interact with immune components of the TME, which can be altered due to specific genetic mutations. The present study evaluates the impact of specific tumour mutations on the response to carboplatin, the current standard of care, and VSV∆M51, a promising OV candidate. After a study of genetically diverse models, constitutive KRas activation enhanced VSV∆M51 replication in-vitro and sensitivity in syngeneic in-vivo models. VSV∆M51 prolonged survival in syngeneic tumour- bearing mice with KRas, Trp53 and Pten mutations, including one tumour model that did not respond to carboplatin. Response to VSV∆M51 in-vivo was associated with activation of CD4+ and CD8+ T lymphocytes in the peritoneal TME. In summary, VSV∆M51-based immunotherapy has shown promise in diverse murine models of EOC bearing clinically relevant mutations.

No description available.

Understanding how genetic variation is passed on from parent to offspring in a species isfundamental to understanding its evolution. Yet, little is known about the exact processescontrolling inheritance in fungi, for instance when the germ cell fate is defined, i.e., when thedistinction between somatic cells and the zygote forming cells happens. The assumption has longbeen that fungi have late rather than early on in development germline sequestration.Consequently, somatic mutations are assumed to be passed on to the offspring in fungi. However,there is a lack of molecular data confirming this assumption. In this project, I have traced thedistribution and frequencies of novel mutations within fruiting bodies of a fairy ring of aMarasmius oreades individual, with the ultimate goal to explore potential mechanisms forcontrolling inheritance of genetic variation in fungi. I called for putative mutations in high readdepth coverage Illumina sequencing data (aiming for 400X) from 36 different tissue samples,collected from seven different fruiting bodies, and was able to identify 40 novel mutations in thewhole dataset. Thirty-two of these 40 mutations were shared between several fruiting bodies,while the remaining eight were unique to a single fruiting body. In general, the number, as wellas the frequency, of mutations decreased from the stipe to the lamella and spores. However, fourof the identified mutations reached a frequency close to 0.5 in the spore samples they were found.These findings do not exclude the possibility of an early-sequestered germline in M. oreades, butalso could be indicative of intraorganismal selection. Although more studies are needed to drawany definite conclusions, the data presented here exemplifies the complexity of fungal geneticsand underscores the need of re-evaluation of old assumptions.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13583号 / 論医博第2303号 / 新制||医||1070(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 滝田 順子, 教授 小川 誠司, 教授 松田 文彦 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM