Project acronym BCLYM
Project Molecular mechanisms of mature B cell lymphomagenesis
Researcher (PI) Almudena Ramiro
Host Institution (HI) CENTRO NACIONAL DE INVESTIGACIONESCARDIOVASCULARES CARLOS III (F.S.P.)
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Most of the lymphomas diagnosed in the western world are originated from mature B cells. The hallmark of these malignancies is the presence of recurrent chromosome translocations that usually involve the immunoglobulin loci and a proto-oncogene. As a result of the translocation event the proto-oncogene becomes deregulated under the influence of immunoglobulin cis sequences thus playing an important role in the etiology of the disease. Upon antigen encounter mature B cells engage in the germinal center reaction, a complex differentiation program of critical importance to the development of the secondary immune response. The germinal center reaction entails the somatic remodelling of immunoglobulin genes by the somatic hypermutation and class switch recombination reactions, both of which are triggered by Activation Induced Deaminase (AID). We have previously shown that AID also initiates lymphoma-associated c-myc/IgH chromosome translocations. In addition, the germinal center reaction involves a fine-tuned balance between intense B cell proliferation and program cell death. This environment seems to render B cells particularly vulnerable to malignant transformation. We aim at studying the molecular events responsible for B cell susceptibility to lymphomagenesis from two perspectives. First, we will address the role of AID in the generation of lymphomagenic lesions in the context of AID specificity and transcriptional activation. Second, we will approach the regulatory function of microRNAs of AID-dependent, germinal center events. The proposal aims at the molecular understanding of a process that lies in the interface of immune regulation and oncogenic transformation and therefore the results will have profound implications both to basic and clinical understanding of lymphomagenesis.
Summary
Most of the lymphomas diagnosed in the western world are originated from mature B cells. The hallmark of these malignancies is the presence of recurrent chromosome translocations that usually involve the immunoglobulin loci and a proto-oncogene. As a result of the translocation event the proto-oncogene becomes deregulated under the influence of immunoglobulin cis sequences thus playing an important role in the etiology of the disease. Upon antigen encounter mature B cells engage in the germinal center reaction, a complex differentiation program of critical importance to the development of the secondary immune response. The germinal center reaction entails the somatic remodelling of immunoglobulin genes by the somatic hypermutation and class switch recombination reactions, both of which are triggered by Activation Induced Deaminase (AID). We have previously shown that AID also initiates lymphoma-associated c-myc/IgH chromosome translocations. In addition, the germinal center reaction involves a fine-tuned balance between intense B cell proliferation and program cell death. This environment seems to render B cells particularly vulnerable to malignant transformation. We aim at studying the molecular events responsible for B cell susceptibility to lymphomagenesis from two perspectives. First, we will address the role of AID in the generation of lymphomagenic lesions in the context of AID specificity and transcriptional activation. Second, we will approach the regulatory function of microRNAs of AID-dependent, germinal center events. The proposal aims at the molecular understanding of a process that lies in the interface of immune regulation and oncogenic transformation and therefore the results will have profound implications both to basic and clinical understanding of lymphomagenesis.
Max ERC Funding
1 596 000 €
Duration
Start date: 2008-12-01, End date: 2014-11-30
Project acronym DYNACOM
Project From Genome Integrity to Genome Plasticity:
Dynamic Complexes Controlling Once per Cell Cycle Replication
Researcher (PI) Zoi Lygerou
Host Institution (HI) PANEPISTIMIO PATRON
Call Details Starting Grant (StG), LS3, ERC-2011-StG_20101109
Summary Accurate genome duplication is controlled by multi-subunit protein complexes which associate with chromatin and dictate when and where replication should take place. Dynamic changes in these complexes lie at the heart of their ability to ensure the maintenance of genomic integrity. Defects in origin bound complexes lead to re-replication of the genome across evolution, have been linked to DNA-replication stress and may predispose for gene amplification events. Such genomic aberrations are central to malignant transformation.
We wish to understand how once per cell cycle replication is normally controlled within the context of the living cell and how defects in this control may result in loss of genome integrity and provide genome plasticity. To this end, live cell imaging in human cells in culture will be combined with genetic studies in fission yeast and modelling and in silico analysis.
The proposed research aims to:
1. Decipher the regulatory mechanisms which act in time and space to ensure once per cell cycle replication within living cells and how they may be affected by system aberrations, using functional live cell imaging.
2. Test whether aberrations in the licensing system may provide a selective advantage, through amplification of multiple genomic loci. To this end, a natural selection experiment will be set up in fission yeast .
3. Investigate how rereplication takes place along the genome in single cells. Is there heterogeneity amongst a population, leading to a plethora of different genotypes? In silico analysis of full genome DNA rereplication will be combined to single cell analysis in fission yeast.
4. Assess the relevance of our findings for gene amplification events in cancer. Does ectopic expression of human Cdt1/Cdc6 in cancer cells enhance drug resistance through gene amplification?
Our findings are expected to offer novel insight into mechanisms underlying cancer development and progression.
Summary
Accurate genome duplication is controlled by multi-subunit protein complexes which associate with chromatin and dictate when and where replication should take place. Dynamic changes in these complexes lie at the heart of their ability to ensure the maintenance of genomic integrity. Defects in origin bound complexes lead to re-replication of the genome across evolution, have been linked to DNA-replication stress and may predispose for gene amplification events. Such genomic aberrations are central to malignant transformation.
We wish to understand how once per cell cycle replication is normally controlled within the context of the living cell and how defects in this control may result in loss of genome integrity and provide genome plasticity. To this end, live cell imaging in human cells in culture will be combined with genetic studies in fission yeast and modelling and in silico analysis.
The proposed research aims to:
1. Decipher the regulatory mechanisms which act in time and space to ensure once per cell cycle replication within living cells and how they may be affected by system aberrations, using functional live cell imaging.
2. Test whether aberrations in the licensing system may provide a selective advantage, through amplification of multiple genomic loci. To this end, a natural selection experiment will be set up in fission yeast .
3. Investigate how rereplication takes place along the genome in single cells. Is there heterogeneity amongst a population, leading to a plethora of different genotypes? In silico analysis of full genome DNA rereplication will be combined to single cell analysis in fission yeast.
4. Assess the relevance of our findings for gene amplification events in cancer. Does ectopic expression of human Cdt1/Cdc6 in cancer cells enhance drug resistance through gene amplification?
Our findings are expected to offer novel insight into mechanisms underlying cancer development and progression.
Max ERC Funding
1 531 000 €
Duration
Start date: 2012-02-01, End date: 2017-01-31
Project acronym FliesCan
Project Modelling Cancer Traits in Drosophila
Researcher (PI) Cayetano Gonzalez Hernandez
Host Institution (HI) FUNDACIO INSTITUT DE RECERCA BIOMEDICA (IRB BARCELONA)
Call Details Advanced Grant (AdG), LS3, ERC-2011-ADG_20110310
Summary Despite significant advance, cancer treatment remains suboptimal. Anatomical and physiological differences between humans and simple model organisms like Drosophila are many and major, and preclude the modelling of key aspects of the disease as it proceeds in vertebrates. However, malignant tumors in vertebrates and flies are made of cells that have derailed from their normal course of development, grow out of control, become immortal, invasive, and kill the host. Moreover, like most solid human tumors, Drosophila malignant tumors display chromosomal instability and copy number variation. In addition, some of them are characterized by the upregulation of germline genes, a distinct feature of certain human cancers. Drosophila tumor models offer an unprecedented opportunity to study these basic malignant traits, which characterize human tumors, in a genetically tractable organism, applying sophisticated genome-wide and comprehensive functional assays at a rate and with a level of detail that are not possible in vertebrates. The goal of this project is twofold: (1) to identify new paths of intervention to inhibit tumor growth, and (2) to determine the origin and function of aneuploidy and changes in gene copy number in malignant growth. We are expectant that the results obtained during the course of this project might eventually have a real impact in human health.
Summary
Despite significant advance, cancer treatment remains suboptimal. Anatomical and physiological differences between humans and simple model organisms like Drosophila are many and major, and preclude the modelling of key aspects of the disease as it proceeds in vertebrates. However, malignant tumors in vertebrates and flies are made of cells that have derailed from their normal course of development, grow out of control, become immortal, invasive, and kill the host. Moreover, like most solid human tumors, Drosophila malignant tumors display chromosomal instability and copy number variation. In addition, some of them are characterized by the upregulation of germline genes, a distinct feature of certain human cancers. Drosophila tumor models offer an unprecedented opportunity to study these basic malignant traits, which characterize human tumors, in a genetically tractable organism, applying sophisticated genome-wide and comprehensive functional assays at a rate and with a level of detail that are not possible in vertebrates. The goal of this project is twofold: (1) to identify new paths of intervention to inhibit tumor growth, and (2) to determine the origin and function of aneuploidy and changes in gene copy number in malignant growth. We are expectant that the results obtained during the course of this project might eventually have a real impact in human health.
Max ERC Funding
2 406 000 €
Duration
Start date: 2012-07-01, End date: 2017-06-30
Project acronym GADD45&P38SIGNALING
Project Role of the Gadd45 family and p38 MAPK in tumor suppression and autoimmunity
Researcher (PI) Jesús Salvador
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Gadd45 family proteins play a critical role in genomic stability, cell cycle regulation proliferation and apoptosis. Gadd45a is activated by the tumor suppressor gene p53, which is mutated in >50% of human tumors. The lack of GADD45a in mice leads to spontaneous development of an autoimmune disease similar to systemic lupus erythematosus. The molecular mechanisms that cause autoimmunity are poorly understood. Recent evidence suggests that p38 activation is involved in autoimmune development and tumor suppression. We found that Gadd45a negatively regulates p38 activity in T cells by preventing phosphorylation on Tyr323. Inhibition of Tyr323p38 phosphorylation is a potential therapeutic target in several types of leukemia and autoimmune diseases, including lupus and rheumatoid arthritis. The main goals of this project are a) to study the in vivo function of the Gadd45 family and p38 in tumor suppression and autoimmunity, and b) to analyze their molecular mechanisms to identify targets for disease treatment. We will dissect the signaling pathways involved in development of autoimmunity and cancer using a multidisciplinary approach that combines mouse genetic, human epigenetic, biochemical, molecular biological and immunological techniques. Our project involves the characterization of murine models deficient in each member of the Gadd45 family (Gadd45a, Gadd45b, Gadd45g), as well as double- and triple-knockout mice, development of a knock-in model for p38a, in vivo and in vitro analysis of T cell activation, proliferation, apoptosis and differentiation, epigenetic studies of potential targets, and finally, validation of these results in autoimmune disease and cancer patients. The results of this project will help identify new therapeutic targets for autoimmune diseases and/or cancer.
Summary
Gadd45 family proteins play a critical role in genomic stability, cell cycle regulation proliferation and apoptosis. Gadd45a is activated by the tumor suppressor gene p53, which is mutated in >50% of human tumors. The lack of GADD45a in mice leads to spontaneous development of an autoimmune disease similar to systemic lupus erythematosus. The molecular mechanisms that cause autoimmunity are poorly understood. Recent evidence suggests that p38 activation is involved in autoimmune development and tumor suppression. We found that Gadd45a negatively regulates p38 activity in T cells by preventing phosphorylation on Tyr323. Inhibition of Tyr323p38 phosphorylation is a potential therapeutic target in several types of leukemia and autoimmune diseases, including lupus and rheumatoid arthritis. The main goals of this project are a) to study the in vivo function of the Gadd45 family and p38 in tumor suppression and autoimmunity, and b) to analyze their molecular mechanisms to identify targets for disease treatment. We will dissect the signaling pathways involved in development of autoimmunity and cancer using a multidisciplinary approach that combines mouse genetic, human epigenetic, biochemical, molecular biological and immunological techniques. Our project involves the characterization of murine models deficient in each member of the Gadd45 family (Gadd45a, Gadd45b, Gadd45g), as well as double- and triple-knockout mice, development of a knock-in model for p38a, in vivo and in vitro analysis of T cell activation, proliferation, apoptosis and differentiation, epigenetic studies of potential targets, and finally, validation of these results in autoimmune disease and cancer patients. The results of this project will help identify new therapeutic targets for autoimmune diseases and/or cancer.
Max ERC Funding
1 755 805 €
Duration
Start date: 2008-09-01, End date: 2014-08-31
Project acronym PAGE
Project The role of mRNA-processing bodies in ageing
Researcher (PI) Popi Syntichaki
Host Institution (HI) IDRYMA IATROVIOLOGIKON EREUNON AKADEMIAS ATHINON
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Recently, we and others have revealed that, in the nematode Caenorhabditis elegans, reduction of protein synthesis rates in somatic cells extends lifespan. Based on this, we postulate that the molecular factors and mechanisms that control the mRNA metabolism in post-mitotic cells are critical determinants of ageing. This project will validate this hypothesis using C. elegans as main model system, but parallel studies in Saccharomyces cerevisiae and Drosophila melanogaster will prove the conservation of our observations. The cellular factors involved in mRNA metabolism (degradation/storage) are localized at specific particles in the cytoplasm of all eukaryotic cells, termed mRNA processing (P) bodies. Additionally, stress granules are cytoplasmic sites of mRNA-metabolism that are formed under stress conditions in mammalian cells. The objectives of this project include: -Monitoring of both P bodies and stress granules in adult worms and characterization of the age-related alterations in their profile, by immunostaining and real-time fluorescence imaging -Direct alterations in the expression of genes encoding factors of each particle in wild-type worms and analysis of the effects on lifespan and stress resistance -Comparison of the age-related changes in the profile of P bodies and stress granules between wild-type and long- or short-lived mutant worms -Direct alterations in the expression of genes encoding factors of each particle in worms with altered lifespan and investigation of the effects on lifespan and stress resistance -Observation of the age-related alterations in the profile of P bodies in yeast and flies, both in wild-type and long-lived strains. The rationale for this project is to provide insight into the modulation of ageing and stress resistance at the level of mRNA metabolism, which is a yet unexplored field of the biology of ageing and global stress response.
Summary
Recently, we and others have revealed that, in the nematode Caenorhabditis elegans, reduction of protein synthesis rates in somatic cells extends lifespan. Based on this, we postulate that the molecular factors and mechanisms that control the mRNA metabolism in post-mitotic cells are critical determinants of ageing. This project will validate this hypothesis using C. elegans as main model system, but parallel studies in Saccharomyces cerevisiae and Drosophila melanogaster will prove the conservation of our observations. The cellular factors involved in mRNA metabolism (degradation/storage) are localized at specific particles in the cytoplasm of all eukaryotic cells, termed mRNA processing (P) bodies. Additionally, stress granules are cytoplasmic sites of mRNA-metabolism that are formed under stress conditions in mammalian cells. The objectives of this project include: -Monitoring of both P bodies and stress granules in adult worms and characterization of the age-related alterations in their profile, by immunostaining and real-time fluorescence imaging -Direct alterations in the expression of genes encoding factors of each particle in wild-type worms and analysis of the effects on lifespan and stress resistance -Comparison of the age-related changes in the profile of P bodies and stress granules between wild-type and long- or short-lived mutant worms -Direct alterations in the expression of genes encoding factors of each particle in worms with altered lifespan and investigation of the effects on lifespan and stress resistance -Observation of the age-related alterations in the profile of P bodies in yeast and flies, both in wild-type and long-lived strains. The rationale for this project is to provide insight into the modulation of ageing and stress resistance at the level of mRNA metabolism, which is a yet unexplored field of the biology of ageing and global stress response.
Max ERC Funding
1 080 000 €
Duration
Start date: 2008-09-01, End date: 2014-08-31
Project acronym RevMito
Project Deciphering and reversing the consequences of mitochondrial DNA damage
Researcher (PI) Cory Dunn
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Starting Grant (StG), LS3, ERC-2014-STG
Summary Mitochondrial DNA (mtDNA) encodes several proteins playing key roles in bioenergetics. Pathological mutations of mtDNA can be inherited or may accumulate following treatment for viral infections or cancer. Furthermore, many organisms, including humans, accumulate significant mtDNA damage during their lifespan, and it is therefore possible that mtDNA mutations can promote the aging process.
There are no effective treatments for most diseases caused by mtDNA mutation. An understanding of the cellular consequences of mtDNA damage is clearly imperative. Toward this goal, we use the budding yeast Saccharomyces cerevisiae as a cellular model of mitochondrial dysfunction. Genetic manipulation and biochemical study of this organism is easily achieved, and many proteins and processes important for mitochondrial biogenesis were first uncovered and best characterized using this experimental system. Importantly, current evidence suggests that processes required for survival of cells lacking a mitochondrial genome are widely conserved between yeast and other organisms, making likely the application of our findings to human health.
We will study the repercussions of mtDNA damage by three different strategies. First, we will investigate the link between a conserved, nutrient-sensitive signalling pathway and the outcome of mtDNA loss, since much recent evidence points to modulation of such pathways as a potential approach to increase the fitness of cells with mtDNA damage. Second, we will explore the possibility that defects in cytosolic proteostasis are precipitated by mtDNA mutation. Third, we will apply the knowledge and concepts gained in S. cerevisiae to both candidate-based and unbiased searches for genes that determine the aftermath of severe mtDNA damage in human cells. Beyond the mechanistic knowledge of mitochondrial dysfunction that will emerge from this project, we expect to identify new avenues toward the treatment of mitochondrial disease.
Summary
Mitochondrial DNA (mtDNA) encodes several proteins playing key roles in bioenergetics. Pathological mutations of mtDNA can be inherited or may accumulate following treatment for viral infections or cancer. Furthermore, many organisms, including humans, accumulate significant mtDNA damage during their lifespan, and it is therefore possible that mtDNA mutations can promote the aging process.
There are no effective treatments for most diseases caused by mtDNA mutation. An understanding of the cellular consequences of mtDNA damage is clearly imperative. Toward this goal, we use the budding yeast Saccharomyces cerevisiae as a cellular model of mitochondrial dysfunction. Genetic manipulation and biochemical study of this organism is easily achieved, and many proteins and processes important for mitochondrial biogenesis were first uncovered and best characterized using this experimental system. Importantly, current evidence suggests that processes required for survival of cells lacking a mitochondrial genome are widely conserved between yeast and other organisms, making likely the application of our findings to human health.
We will study the repercussions of mtDNA damage by three different strategies. First, we will investigate the link between a conserved, nutrient-sensitive signalling pathway and the outcome of mtDNA loss, since much recent evidence points to modulation of such pathways as a potential approach to increase the fitness of cells with mtDNA damage. Second, we will explore the possibility that defects in cytosolic proteostasis are precipitated by mtDNA mutation. Third, we will apply the knowledge and concepts gained in S. cerevisiae to both candidate-based and unbiased searches for genes that determine the aftermath of severe mtDNA damage in human cells. Beyond the mechanistic knowledge of mitochondrial dysfunction that will emerge from this project, we expect to identify new avenues toward the treatment of mitochondrial disease.
Max ERC Funding
1 497 160 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
