ERC FUNDED PROJECTS

Despite considerable advances in drug discovery, resistance to anticancer chemotherapy confounds the effective treatment of patients. Cancer cells can acquire broad cross-resistance to mechanistically and structurally unrelated drugs. P-glycoprotein (Pgp) actively extrudes many types of drugs from cancer cells, thereby conferring resistance to those agents. The central tenet of my work is that Pgp, a universally accepted biomarker of drug resistance, should in addition be considered as a molecular target of multidrug-resistant (MDR) cancer cells. Successful targeting of MDR cells would reduce the tumor burden and would also enable the elimination of ABC transporter-overexpressing cancer stem cells that are responsible for the replenishment of tumors. The proposed project is based on the following observations: - First, by using a pharmacogenomic approach, I have revealed the hidden vulnerability of MDRcells (Szakács et al. 2004, Cancer Cell 6, 129-37); - Second, I have identified a series of MDR-selective compounds with increased toxicity toPgp-expressing cells (Turk et al.,Cancer Res, 2009. 69(21)); - Third, I have shown that MDR-selective compounds can be used to prevent theemergence of MDR (Ludwig, Szakács et al. 2006, Cancer Res 66, 4808-15); - Fourth, we have generated initial pharmacophore models for cytotoxicity and MDR-selectivity (Hall et al. 2009, J Med Chem 52, 3191-3204). I propose a comprehensive series of studies that will address thefollowing critical questions: - First, what is the scope of MDR-selective compounds? - Second, what is their mechanism of action? - Third, what is the optimal therapeutic modality? Extensive biological, pharmacological and bioinformatic analyses will be utilized to address four major specific aims. These aims address basic questions concerning the physiology of MDR ABC transporters in determining the mechanism of action of MDR-selective compounds, setting the stage for a fresh therapeutic approach that may eventually translate into improved patient care.

1 499 640 €

Start date: 2012-01-01, End date: 2016-12-31

We are largely unaware of our own motives. Understanding our motives can be reduced to knowing how we form goals and these goals translate into behavior. Goals can be defined as pleasurable situations that we particularly value and that we intend to reach. Recent investigation in the emerging field of neuro-economics has put forward a neuronal network constituting a brain valuation system (BVS). We wish to build a more comprehensive account of motivational processes, investigating not only valuation and choice but also effort (how much energy we would spend to attain a goal). More specifically, our aims are to better describe 1) how the brain assigns values to various objects and actions, 2) how values depend on parameters such as reward magnitude, probability, delay and cost, 3) how values are affected by social contexts, 4) how values are modified through learning and 5) how values influence the brain systems (perceptual, cognitive and motor) that underpin behavioral performance. To these aims, we would combine three approaches: 1) human cognitive neuroscience, which is central as we ultimately wish to understand ourselves, as well as human pathological conditions where motivation is either deficient (apathy) or out of control (compulsion), 2) primate neurophysiology, which is essential to describe information processing at the single-unit level and to derive causality by observing behavioral consequences of brain manipulations, 3) computational modeling, which is mandatory to link quantitatively the different descriptions levels (single-unit recordings, local field potentials, regional BOLD signal, vegetative manifestations and motor outputs). A bayesian framework will be developed to infer from experimental measures the subjects prior beliefs and value functions. We believe that our team, bringing together three complementary perspectives on motivation within a clinical environment, would represent a unique education and research center in Europe.

1 346 000 €

Start date: 2011-03-01, End date: 2016-08-31

The eukaryotic genome is packaged into large-scale chromatin structures that occupy distinct domains in the nucleus and this organization is now seen as a key contributor to genome functions. Two key functions of the genome can take advantage of nuclear organization: regulated gene expression and the propagation of a stable genome. To understand these fundamental processes, we have chosen to use yeast as a model system that allows genetics, molecular biology and advanced live microscopy approaches to be combined. Budding yeast have been very powerful to demonstrate that gene position can play an active role in regulating gene expression. Distinct subcompartments dedicated to either gene silencing or activation of specific genes are positioned at the nuclear periphery. To gain insight into the mechanisms underlying this sub-compartmentalization, we will address three complementary issues: - What are the mechanisms involved in the establishment and maintenance of silent nuclear compartments? - How and why are some activated genes recruited to the nuclear periphery? - What are the relationships between repressive and activating nuclear compartments? Concerning the maintenance of genome integrity, recent advances in yeast highlight the importance of nuclear architecture. However, how nuclear organization influences the formation and processing of DNA lesions remain poorly understood. We will focus on two main questions: - How and where in the nucleus are double strand breaks recognized, processed, and repaired? - Where do breaks or gaps resulting from replicative stress at 'fragile sites' arise in the nucleus and how does nuclear organization influence their stability? We hope to gain a better understanding of the mechanisms presiding nuclear organization and its importance for genome functions. These mechanisms are likely to be conserved and will be subsequently tested in higher eukaryotic cells.

1 000 000 €

Start date: 2008-09-01, End date: 2014-05-31

With the availability of the essentially complete sequence of the human genome, as well as a rapid development of massive sequencing techniques, the research efforts to understand genetics and disease from a cis standpoint will soon reach an endpoint. However, our emerging knowledge of gene regulation networks reveals that epigenetic regulation of the hereditary information plays crucial roles in various biological events through its influence on processes such as transcription, DNA replication and chromosome architecture. Another scenario in which the control of chromatin structure is crucial is the repair of lesions in genomic DNA. There is mounting evidence, particularly from model organisms such as Saccharomyces cerevisiae, that histone modifying enzymes (acetylases, deacetylases, kinases, …) are essential components of the machinery that maintains genome integrity and thereby guards against cancer, degenerative diseases and ageing. However, little is known about the specific “code” of histone tail modifications that coordinate DNA repair, and the impact that an aberrant “histone code” may have on human health. In CHROMOREPAIR we will systematically analyze the chromatin remodelling process that undergoes at DNA lesions and evaluate the impact that chromatin alterations have on the access, signaling and repair of DNA damage. Furthermore, we propose to translate our in vitro knowledge to the development of mouse models that help us evaluate how modulation of chromatin status impinges on genome maintenance and therefore on cancer and aging. As a provocative line of research and based on our preliminary data, we propose that certain chromatin alterations could not only impair but also in some cases promote a more robust response to DNA breaks, which could be a novel and not yet explored way to potentiate the elimination of pre-cancerous cells.

948 426 €

Start date: 2008-12-01, End date: 2013-11-30