ERC FUNDED PROJECTS

Transcriptional dyregulation is a common driver in cancer and acute myeloid leukemia (AML) is an exemplar of this process. AML has a dismal survival rate of <30% with novel targeted therapies urgently required. My research focuses on improving our understanding of the biology of AML and using this knowledge to develop targeted therapies to improve outcomes. Recently loss-of-function mutations in members of the cohesin complex have been described in up to 15% of patients with AML. The cohesin complex mediates sister chromatid cohesion, an important process for DNA repair and proper chromosomal segregation. It has also recently been demonstrated to be important for transcriptional regulation, due to its coordination of communication between promoters and enhancer and insulator elements. Evidence suggests that transcriptional alterations underlie the mechanisms of transformation by cohesin mutations in AML. However, other evidence and my preliminary data also suggest cohesin mutant cells to have specific vulnerabilities related to their roles in proper chromosome segregation and DNA repair that can be specifically targeted. Objectives: 1) Generation of mouse models of cohesin-mutated AML. To model AML in vivo and as a resources for Obj 2-4 2) Characterisation of transcriptional defects in cohesin-mutated AML using state-of-the-art genomic techniques (RNA-Seq, ChIP-Seq and Capture Hi-C) 3) Define mechanisms of cohesin-mediated transcriptional regulation in normal hematopoiesis and its alteration in leukaemia using SILAC based proteomics and ChIP-Seq co-binding 4) Therapeutic targeting of the cohesin complex in cohesin-mutant AML using compounds identified in a large screen and suggested by Obj 1-3 and tested in cell lines, patient samples and in vivo models. This proposal will inform mechanisms of transcriptional regulation that occur during normal hematopoiesis and how these are altered in AML. It will also identify candidate therapies for this aggressive disease

1 999 574 €

Start date: 2015-09-01, End date: 2020-08-31

Nowadays, ageing is one of the main problems in Western society. The increase in the percentage of elderly people serves to strain the Social Security to the point of bankruptcy. The only way to alleviate the suffering caused by age-related degenerative disease is to fully understand the underlying forces which drive ageing and design strategies to delay it. Mitochondria are considered as central modulators of longevity in different species. It has been proposed that free radicals cause the accumulation of oxidative damage and as a result ageing. In accordance with this, production of Reactive Oxygen Species (ROS) by complex I negatively correlates with longevity. However, the overexpression of antioxidants or the reduction of ROS levels does not increase lifespan. These contradictory data can only be reconciled if complex I is modulating longevity through a ROS independent mechanism. We have expressed the alternative internal NADH dehydrogenase 1 (NDI1) from Saccharomyces cerevisiae in Drosophila melanogaster. The expression of NDI1 does not change the level of ROS but increases both the ratio of NAD+/NADH and Drosophila longevity. The main objective of this proposal is to study the mechanisms by which complex I regulates longevity. My general hypothesis is that complex I regulates longevity through a ROS independent mechanism. I propose that complex I controls the cellular levels of NAD+/NADH, keeping their levels at an equilibrium that favours the optimal functioning of the cell. When the ratio is moved towards NADH ageing is promoted, whereas when it is moved towards NAD+ pro-survival pathways are activated. I proposed two specific mechanisms downstream of complex I that promote cellular longevity or senescence: 1) activation of sirtuins, which would increase genome stability and 2) reduction of methylglyoxal generation, which would decrease the accumulation of cellular garbarge .

1 491 600 €

Start date: 2011-02-01, End date: 2016-09-30

Neurodegenerative diseases (NDs) are incurable, debilitating conditions, arise mid-late in life, represent an enormous health and socioeconomic burden and no therapies exist. An enigmatic finding in NDs is the early and selective alteration in intrinsic excitability of vulnerable neurons paralleling changes in its circuitry. However, a gap in understanding exists in ND field about the cause of these alterations and whether these modifications regulate degenerative pathomechanisms. Our recent study, examining mechanisms of Purkinje cell (PC) degeneration in Spinocerebellar ataxia type 1 (SCA1) revealed that the earliest cerebellar alterations occur in the major excitatory inputs onto PCs, the climbing fibers (CFs). Based on this, we propose a novel three-step model of neurodegeneration: First, suboptimal functioning of the presynaptic inputs initiates signaling deficits in target PCs. Second, those alterations trigger maladaptive responses such as altered intrinsic PC excitability, thus amplifying pathogenic cascades. Third, at network level progressive dysfunction triggers compensatory synaptic modifications within the cerebellar circuitry. In this proposal, we will test our new hypothesis for NDs on SCA1 and this will be the first study to test circuit-dependency in NDs by selectively silencing presynaptic inputs and examining molecular responses in the postsynaptic neuron. Specifically, we will 1) Identify the dysfunctional CF associated molecular signature in PCs. 2) Elucidate mechanisms involved in altering intrinsic PC excitability. 3) Map the connectome for a structural correlate of the pathology. Using conditional mouse models, pharmacogenetics, transcriptomics, proteomics and connectomics, we will delineate molecular alterations that govern disease from compensatory alterations. Our systematic approach will not only impact SCA related therapies but the entire spectrum of NDs and has the potential to change the conceptual approach of future studies on NDs.

2 000 000 €

Start date: 2017-06-01, End date: 2022-05-31

Vertebrates contain hundreds of different cell types which maintain phenotypic identity by a combination of epigenetic programming and genomic regulation. Systems biology approaches are now used in a number of laboratories to determine how transcription factors and chromatin marks pattern the human genome. Despite high conservation of the cellular and molecular function of many mammalian transcription factors, our recent experiments in matched mouse and human tissues indicates that most transcription factor binding events to DNA are very poorly conserved. A hypothesis that could account for this apparent divergence is that the larger regional pattern of transcription factor binding may be conserved. To test this, (1) we are characterizing the global transcriptional profile, chromatin state, and complete genomic occupancy of a set of tissue-specific transcription factors in hepatocytes of strategically chosen mammals; (2) to further identify the precise mechanistic contribution of cis and trans effects, we are comparing transcription factor binding at homologous regions of human and mouse DNA in a mouse line that carries human chromosome 21. Together, these projects will provide insight into the general principles of how transcriptional networks are evolutionarily conserved to regulate cell fate specification and function using a clinically important cell type as a model.

960 000 €

Start date: 2008-10-01, End date: 2013-09-30