This thesis addresses the repair of DNA double-strand breaks (DSBs) that arise in different contexts, both artificially inflicted DNA damage and spontaneously arising breaks. We have found that the... Show moreThis thesis addresses the repair of DNA double-strand breaks (DSBs) that arise in different contexts, both artificially inflicted DNA damage and spontaneously arising breaks. We have found that the (mutational) repair outcome of a DSB depends on the context in which it occurs. When cells are not replicating, DSBs are repaired via non-homologous end-joining (NHEJ). NHEJ efficiency can be affected by defective RNA processing. In replicating cells, the preferable mechanism for DSB repair is homologous recombination (HR). When canonical HR cannot be executed, because the repair template is not available (at G4-induced breaks, for example) or when not all HR factors are present (in BRCA1 deficient situations), alternative annealing is needed. This is carried out via polymerase theta-mediated end-joining (TMEJ), or when homologous nucleotides are available, via HELQ-1 mediated annealing of these homologous stretches. Finally, we have found that large tandem duplications can arise when break ends cannot anneal properly after the extension step in HR. Show less
In this thesis I describe the developmental role of the Y-family polymerases Pol Eta, Pol Kappa and Rev1 in protection against exogenous and endogenous damage in C. elegans. Furthermore I identify... Show moreIn this thesis I describe the developmental role of the Y-family polymerases Pol Eta, Pol Kappa and Rev1 in protection against exogenous and endogenous damage in C. elegans. Furthermore I identify a new role for the A-family Polymerase Pol Theta in repair of replication-associated breaks. Show less
This thesis, titled __Genetic and pharmacogenetic determinants of cardiovascular disease__ is divided in three sections. In section one the genetic determinants of coronary restenosis are explored.... Show moreThis thesis, titled __Genetic and pharmacogenetic determinants of cardiovascular disease__ is divided in three sections. In section one the genetic determinants of coronary restenosis are explored. In the first genome-wide association study on this condition, in the GENetic DEterminants of Restenosis study, we describe a novel locus on chromosome 12 possibly associated with restenosis. Furthermore, by using several analysis tools on this data, we describe multiple biological pathways and genes that are likely associated with restenosis. In section two, we focus on genetic factors involved in three other (cardio)vascular diseases. We explore the role of DNA repair genes in myocardial infarction and stroke and the genetic determinants of dialysis shunt failure. Section three is on pharmacogenetics. In particular, we were interested in genetic variation involved in aspirin and clopidogrel resistance. We validated two genetic polymorphisms associated with recurrent thrombotic events during treatment with these agents in patients with an acute myocardial infarction. Genetic research is a fast developing field of research. By increasing our knowledge on the molecular background of diseases, genetics potentially could lead to more personalized treatment in the near future. Show less
