ERC FUNDED PROJECTS

During the human lifetime 10000 trillion cell divisions take place to ensure tissue homeostasis and several vital functions in the organism. Mitosis is the process that ensures that dividing cells preserve the chromosome number of their progenitors, while deviation from this, a condition known as aneuploidy, represents the most common feature in human cancers. Here we will test two original concepts with strong implications for chromosome segregation fidelity. The first concept is based on the “tubulin code” hypothesis, which predicts that molecular motors “read” tubulin post-translational modifications on spindle microtubules. Our proof-of-concept experiments demonstrate that tubulin detyrosination works as a navigation system that guides chromosomes towards the cell equator. Thus, in addition to regulating the motors required for chromosome motion, the cell might regulate the tracks in which they move on. We will combine proteomic, super-resolution and live-cell microscopy, with in vitro reconstitutions, to perform a comprehensive survey of the tubulin code and the respective implications for motors involved in chromosome motion, mitotic spindle assembly and correction of kinetochore-microtubule attachments. The second concept is centered on the recently uncovered chromosome separation checkpoint mediated by a midzone-associated Aurora B gradient, which delays nuclear envelope reformation in response to incompletely separated chromosomes. We aim to identify Aurora B targets involved in the spatiotemporal regulation of the anaphase-telophase transition. We will establish powerful live-cell microscopy assays and a novel mammalian model system to dissect how this checkpoint allows the detection and correction of lagging/long chromosomes and DNA bridges that would otherwise contribute to genomic instability. Overall, this work will establish a paradigm shift in our understanding of how spatial information is conveyed to faithfully segregate chromosomes during mitosis.

2 323 468 €

Start date: 2016-07-01, End date: 2021-06-30

Conventional cancer therapies suffer from poor efficacy owing to the lack of efficient delivery systems and to the inherent tumor heterogeneity that requires multi-modal approach to abrogate cancer progression. Nanotechnology holds promise to address these drawbacks, as the use of (bio)nanomaterials for diagnostics and therapy has been gaining momentum over the last years. The main goal of this project is to develop a novel and facile platform capable of profiling both the therapy outcome and heterogeneity in cancer, by using bioresponsive nanohydrogels for the delivery of logic multicolor synthetic gene circuits. These logic synthetic gene circuits will be designed as a biobarcode of multicolor RNA circuits embedded in hybrid nanoparticles and doped in hydrogels for local therapy in breast cancer in vivo. Using cell-type specific promoters, the multicolor miRNA circuits will be expressed specifically to each type of the cells of the tumor microenvironment. Subsequently, this will permit to evaluate the therapeutic efficacy in a cell-by-cell basis and to profile the tumor heterogeneity across different breast cancer types. In order to potentiate the translation of this ground-breaking platform into clinics and precision medicine, novel de-regulated miRNA targets will be identified based on screens performed in breast cancer patient-derived tumors that better reflect the heterogeneous tumor microenvironment in a patient-by-patient basis. In sum, the material platforms developed herein and newly identified biological targets can be harnessed to design effective cancer treatments that go beyond breast cancer. The project is highly versatile and multidisciplinary and this system can be easily adapted to target any cancer cell type and molecular mechanisms and translated to clinical testing.

1 435 312 €

Start date: 2020-02-01, End date: 2025-01-31

Epithelia have the essential role of acting as a barrier that protects living organisms and its organs from the surrounding milieu. Therefore, it is crucial for epithelial tissues to have robust ways of maintaining its integrity despite the frequent damage caused by normal cell turnover, inflammation and injury. All epithelia have some capacity to repair themselves, however, the wound-healing process differs dramatically between the developmental stage and type of tissue involved. In this project we will focus on investigating the capacity that several simple epithelial tissues have to reseal small discontinuities very rapidly and efficiently. This repair mechanism that we call epithelial resealing is based on the contraction of an actomyosin purse string in the leading edge cells around the wound margin. Epithelial resealing seems to be a fundamental repair mechanism, acting in several types of simple embryonic and adult epithelia, in both vertebrates and invertebrates. The cell biology of epithelial resealing has started to be understood but there are still many open questions and the signalling cascades that regulate this process are largely unknown. We propose to investigate epithelial resealing using a combination of genetics and high resolution live imaging. The Drosophila embryonic epithelium will be our primary model system and we will start by characterizing in detail novel genes involved in resealing that have been identified in a pilot screen previously performed in the laboratory. We will also perform a new RNAi genetic screen based on a very large collections of transgenic lines to completely unravel the signalling network that controls epithelial resealing. In order to investigate how conserved in vertebrates are the epithelial resealing mechanisms, we will establish epithelial wounding assays in zebrafish simple epithelial tissues and we will study, in this vertebrate model system, the molecular mechanisms that we will uncover using Drosophila.

1 150 000 €

Start date: 2008-11-01, End date: 2014-10-31

Mitochondria at the synapse have a pivotal role in neurotransmitter release, but almost nothing is known about synaptic mitochondria composition or specific functions. Synaptic mitochondria compared to mitochondria in other cells, need to cope with increased calcium load, more oxidative stress, and high demands of energy generation during synaptic activity. My hypothesis is that synaptic mitochondria have acquired specific mechanisms to manage local stress and that disruption of these mechanisms contributes to neurodegeneration. How mitochondria sense their dysfunction is unclear. Even more intriguing is the question how they decide whether their failure should lead to removal of the organelle or dismissal of the complete neuron via cell death. We anticipate that these decisions are not only operational during disease, but might constitute a fundamental mechanism relevant for maintenance of synaptic activity and establishment of new synapses. Recent studies have revealed several genes implicated in neurodegenerative disorders involved in mitochondrial maintenance. However the function of these genes at the synapse, where the initial damage occurs, remains to be clarified. These genes provide excellent starting points to decipher the molecular mechanisms discussed above. Furthermore I propose to use proteomic approaches to identify the protein fingerprint of synaptic mitochondria and to compare them to mitochondria from other tissues. I plan to identify key players of the proposed regulatory pathways involved in intrinsic mitochondria quality control. In a complimentary approach, I will exploit our findings and use in vitro and in vivo experimental approaches to measure mitochondrial function of synaptic versus non-synaptic mitochondria and the relevance of those changes for synaptic function. Our work will unravel the specific properties of synaptic mitochondria and provide much needed insight in their hypothesized predominant role in neurodegenerative disorders.

1 300 000 €

Start date: 2016-09-01, End date: 2022-02-28