ERC FUNDED PROJECTS

Faithful repair of double stranded DNA breaks (DSBs) is essential, as they are at the origin of genome instability, chromosomal translocations and cancer. Cells repair DSBs through different pathways, which can be faithful or mutagenic, and the balance between them at a given locus must be tightly regulated to preserve genome integrity. Although, much is known about DSB repair factors, how the choice between pathways is controlled within the nuclear environment is not understood. We have shown that nuclear architecture and non-random genome organization determine the frequency of chromosomal translocations and that pathway choice is dictated by the spatial organization of DNA in the nucleus. Nevertheless, what determines which pathway is activated in response to DSBs at specific genomic locations is not understood. Furthermore, the impact of 3D-genome folding on the kinetics and efficiency of DSB repair is completely unknown. Here we aim to understand how nuclear compartmentalization, chromatin structure and genome organization impact on the efficiency of detection, signaling and repair of DSBs. We will unravel what determines the DNA repair specificity within distinct nuclear compartments using protein tethering, promiscuous biotinylation and quantitative proteomics. We will determine how DNA repair is orchestrated at different heterochromatin structures using a CRISPR/Cas9-based system that allows, for the first time robust induction of DSBs at specific heterochromatin compartments. Finally, we will investigate the role of 3D-genome folding in the kinetics of DNA repair and pathway choice using single nucleotide resolution DSB-mapping coupled to 3D-topological maps. This proposal has significant implications for understanding the mechanisms controlling DNA repair within the nuclear environment and will reveal the regions of the genome that are susceptible to genomic instability and help us understand why certain mutations and translocations are recurrent in cancer

1 999 750 €

Start date: 2017-03-01, End date: 2022-02-28

Epigenetic alterations can be detected in all cancers and in essentially every patient. Despite their prevalence, the concrete functional roles of these alterations are not well understood, for two reasons: First, cancer samples tend to carry many correlated epigenetic alterations, making it difficult to statistically distinguish relevant driver events from those that co-occur for other reasons. Second, we lack tools for targeted epigenome editing that could be used to validate biological function in perturbation and rescue experiments. The proposed project strives to overcome these limitations through experimental and bioinformatic methods development, with the ambition of making and breaking cancer cells in vitro by introducing defined sets of epigenetic alterations. We will focus on leukemia as our “model cancer” (given its low mutation rate, frequent defects in epigenetic regulators, and availability of excellent functional assays), but the concepts and methods are general. In Aim 1, we will generate epigenome profiles for a human knockout cell collection comprising 100 epigenetic regulators and use the data to functionally annotate thousands of epigenetic alterations observed in large cancer datasets. In Aim 2, we will develop an experimental toolbox for epigenome programming using epigenetic drugs, CRISPR-assisted recruitment of epigenetic modifiers for locus-specific editing, and cell-derived guide RNA libraries for epigenome copying. Finally, in Aim 3 we will explore epigenome programming (methods from Aim 2) of candidate driver events (predictions from Aim 1) with the ultimate goal of converting cancer cells into non-cancer cells and vice versa. In summary, this project will establish a broadly applicable methodology and toolbox for dissecting the functional roles of epigenetic alterations in cancer. Moreover, successful creation of a cancer that is driven purely by epigenetic alterations could challenge our understanding of cancer as a genetic disease.

1 281 205 €

Start date: 2016-12-01, End date: 2021-11-30

Palaeogenomics is the nascent discipline concerned with sequencing and analysis of genome-scale information from historic, ancient, and even extinct samples. While once inconceivable due to the challenges of DNA damage, contamination, and the technical limitations of PCR-based Sanger sequencing, following the dawn of the second-generation sequencing revolution, it has rapidly become a reality. Indeed, so much so, that popular perception has moved away from if extinct species’ genomes can be sequenced, to when it will happen - and even, when will the first extinct animals be regenerated. Unfortunately this view is naïve, and does not account for the financial and technical challenges that face such attempts. I propose an exploration of exactly what the limits on genome reconstruction from extinct or otherwise historic/ancient material are. This will be achieved through new laboratory and bioinformatic developments aimed at decreasing the cost, while concomitantly increasing the quality of genome reconstruction from poor quality materials. In doing so I aim to build a scientifically-grounded framework against which the possibilities and limitations of extinct genome reconstruction can be assessed. Subsequently genomic information will be generated from a range of extinct and near-extinct avian and mammalian species, in order to showcase the potential of reconstructed genomes across research questions spanning at least three different streams of research: De-extinction, Evolutionary Genomics, and Conservation Genomics. Ultimately, achievement of these goals requires formation of a dedicated, closely knit team, focusing on both the methodological challenges as well as their bigger picture application to high-risk high-gain ventures. With ERC funding this can become a reality, and enable palaeogenomics to be pushed to the limits possible under modern technology.

2 000 000 €

Start date: 2016-04-01, End date: 2021-03-31

Decoding of the genome during development and differentiation depends on sequence-specific DNA binding proteins that regulate transcription. The activity of transcription factors is constrained, however, by chromatin structure and by modification of histones and DNA, known collectively as the “epigenome”. Diseased states, particularly cancers, are often accompanied by epigenomic disturbances that contribute to aetiology, but despite much research the molecular determinants of chromatin and DNA marking remain poorly understood. A widespread view is that the epigenome responds to developmental decisions or environmental impacts that are memorised by the epigenetic machinery. Complementary to this “memory” hypothesis, there is evidence that the epigenome can directly reflect the underlying DNA sequence. We aim to explore genetic determinants of the epigenome based on our over-arching hypothesis that chromatin structure is influenced by the interaction of DNA binding proteins with short, frequent base sequence motifs. Prototypes for this scenario are proteins that bind to the two base pair sequence CpG. These proteins accumulate at CpG islands (CGIs), which are platforms for gene regulation, where they recruit multi-protein complexes that lay down epigenetic marks. By identifying and characterising novel DNA-binding proteins that sense global properties of the DNA sequence (e.g. base composition), we will address several major unanswered questions about genome regulation, including the origin of global DNA methylation patterns and the causal basis of higher order chromosome structures. Our research programme will advance genome biology and shed light on the role of epigenetic signalling in development. In particular it will explore the extent to which the epigenome is “hard-wired” by genes, with important implications for health.

2 499 717 €

Start date: 2016-06-01, End date: 2021-05-31