Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: . Includes bibliographical references.

No description available.

BRCA1 is a caretaker of genome integrity with various molecular functions, which are required for development and tumor suppression. These include the homology-directed repair (HDR) of DNA double strand breaks, stalled replication fork protection (SFP), transcription, chromatin remodeling and cell cycle checkpoint control. Recent studies reported that BRCA1 is required for reprogramming to pluripotency, but its specific role remains unknown. In this work, we use separation of function mutants for the roles of BRCA1 in HDR and SFP to show that BRCA1 is required to repair replication-associated DNA double strand breaks by homologous recombination during reprogramming. Deficiency in SFP proved inconsequential to induced pluripotent stem (iPS) cell generation and cells with this phenotype did not experience reduced reprogramming. Thus, the primary limiting factor for the transition to pluripotency is a specific class of DNA damage: double strand breaks, likely occurring in late replicating regions which require repair by homologous recombination. These findings identify an important role of DNA damage, linked to the progression of DNA replication, in limiting cell type transitions during reprogramming. Most studies on iPS cell generation have focused on gene expression as a limiting step, in part due to the wide availability of tools to analyze transcription. Since the progression of DNA replication and DNA damage during S-phase are cell type specific, we have started the development of a sequencing platform to map various aspects of replication progression, such as origin usage, polymerase direction,pausing and stalling. In this work, we demonstrate that nucleotide analogs, incorporated during DNA synthesis in mammalian cells, can be detected by Nanopore sequencing.

Thesis (Ph. D.)--Rutgers University, 2004. / Includes bibliographical references. Also available on the Internet.

No description available.

Thesis (M.S.)--University of Massachusetts Amherst, 2008. / Includes bibliographical references (p. 77-79).

Thesis (M.S.)--Brandeis University, 2009. / Title from PDF title page (viewed on May 29, 2009). Includes bibliographical references.

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Biochemistry. Title from pdf file main screen (viewed on August 11, 2009). Includes bibliographical references.

Source: Masters Abstracts International, Volume: 46-04, page: 2093. Advisers: Xianglin L. Du; Karen H. Lu. Includes bibliographical references.

O câncer de mama é uma das neoplasias malignas mais comuns que afetam mulheres de todo o mundo. No Brasil, o Estado do Rio Grande do Sul tem índices de incidência e mortalidade por câncer de mama que situam-se entre os maiores do país. Aproximadamente 5-10% dos diagnósticos são causados por mutações germinativas em genes de predisposição entre os quais estão BRCA1 e BRCA2, associados à Síndrome de Câncer de mama e Ovário Hereditários (Hereditary Breast and Ovarian Cancer Syndrome ou HBOC, OMIM #114480).A identificação dos casos hereditários de câncer de mama é importante porque indivíduos afetados apresentam risco cumulativo vital muito superior ao da população para o desenvolvimento de câncer, porque familiares de um afetado podem estar igualmente em risco porque há medidas de rastreamento intensivo e intervenções preventivas que podem diminuir significativamente o risco de câncer em portadores de mutação. O diagnóstico molecular da síndrome HBOC é laborioso e caro devido à heterogeneidade molecular da doença. Famílias que apresentam características indicativas de uma síndrome de predisposição ao câncer de mama e ovário hereditários, mas que são negativas para mutações pontuais em BRCA1/2 vêm sendo testadas para grandes rearranjos visto que essas anormalidades têm sido consideradas como respondendo por, no mínimo, 10% do todos os casos HBOC com mutação identificável, incluindo grandes deleções ou duplicações. Um estudo recente de Portugal, demonstrou que um rearranjo fundador no exon 3 de BRCA2 ocorre em por 8% das famílias HBOC do Norte do país. Os objetivos deste trabalho incluíram a verificação da freqüência e caracterização de rearranjos gênicos nos genes BRCA1 e BRCA2, incluindo a mutação fundadora c.156_157insAlu no exon 3 de BRCA2 em famílias brasileiras dealto risco para a síndrome HBOC. Em um grupo de 145 indivíduos em risco nãorelacionados rastreados para a mutação fundadorac.156_157insAlu no exon 3 de BRCA2 foram encontrados 3 portadores da mutação (prevalência de 2%). Em um grupo de 145 indivíduos de risco não-relacionados rastreados para rearranjos gênicos em BRCA1 e BRCA2 pela técnica de MLPA (multiplex ligation-dependent probe amplification) foram identificados 4 portadores de mutação germinativa, sendo a mutação em dois deles um rearranjo gênico no gene BRCA1 (1,4%) envolvendo sequencias Alu. Rearranjos gênicos em BRCA1 e BRCA2 são responsáveis por uma parcela das mutações em famílias HBOC Brasileiras. O presente estudo, envolvendo uma série grande de famílias com o fenótipo da síndrome HBOC, não identificou novos rearranjos fundadores, no entanto, demonstrou a presença de rearranjos tanto em BRCA1 quanto em BRCA2, reiterando a importância da busca ativa por estas alterações, que dificilmente são identificadas por técnicas convencionais de sequenciamento gênico. A técnica de MLPA associada a um protocolo específico para detecção da mutação fundadora Portuguesa c.156_157insAlu podem ser utilizadas como estratégia inicial de rastreamento de mutações em famílias Brasileiras com a síndrome. Os resultados apresentados aqui, no entanto, indicam que mutações serão identificadas em menos de 10% dos casos utilizando esta estratégia. / Breast cancer is one of the most common malignancies affecting women worldwide. In Brazil, the State of Rio Grande do Sul has incidence rates and mortality from breast cancer are among the largest in the country. Approximately 5-10% of the cases are caused by germline mutations in predisposing genes including BRCA1 and BRCA2 are associated with the syndrome of breast and ovarian cancer Hereditary (Hereditary Breast and Ovarian Cancer Syndrome or HBOC, OMIM # 114480). The identification of inherited cases of breast cancer is important because affected individuals have cumulative risk life much higher than the population for developing cancer because of an affected family may also be at risk because there are measures of intensive screening and preventive interventions that can significantly decrease the risk of cancer in mutation carriers. The molecular diagnosis of HBOC syndrome is laborious and expensive due to the molecular heterogeneity of the disease. Families that have characteristics indicative of a cancer predisposition syndrome of hereditary breast and ovarian cancers, but are negative for mutations in BRCA1/2 have been tested for large rearrangements because these abnormalities have been identified as accounting for at least 10 % of all cases HBOC identifiable mutation, including large deletions or duplications. A recent study from Portugal, the founder showed that a rearrangement in exon 3 of BRCA2 occurs in 8% of HBOC families of the north. The objectives of this work included the verification of the frequency and characterization of gene rearrangements in BRCA1 and BRCA2 genes, including c.156_157insAlu founder mutation in exon 3 of BRCA2 mutations in Brazilian families at high risk for HBOC syndrome. In a group of 145 individuals at risk unrelated traced to c.156_157insAlu founder mutation in exon 3 of 3 found BRCA2 mutation carriers (prevalence 2%). In a group of 145 individuals at risk unrelated screened for gene rearrangements in BRCA1 and BRCA2 by the technique of MLPA (multiplex ligationdependent probe amplification) identified four carriers of germline mutation, and two of the mutation in a gene rearrangement in the gene BRCA1 (1.4%) involving Alu sequences. Gene rearrangements in BRCA1 and BRCA2 account for a portion of HBOC mutations in Brazilian families. This study, involving a large series of families with HBOC syndrome phenotype, no new rearrangements identified founders, however, showed the presence of rearrangements in both BRCA1 and BRCA2, reiterating the importance of active search for these changes, which hardly are identified by conventional techniques of gene sequencing. The technique of MLPA protocol associated with a specific mutation detection founder Portuguese c.156_157insAlu strategy can be used as initial screening for mutations in families with Brazilian syndrome. The results presented here, however, indicate mutations that will be identified in less than 10% of the cases using this strategy.