1989 — 1993 |
Orkin, Stuart H |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Genetics @ Harvard University (Medical School) |
1 |
1994 — 2000 |
Orkin, Stuart H |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Training Grant in Genetics @ Harvard University (Medical School) |
1 |
2001 — 2004 |
Orkin, Stuart H |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Molecular Mechanisms of Tissue Stem Cell Plasticity @ Dana-Farber Cancer Institute
DESCRIPTION (provided by applicant): Recent findings lead to a reassessment of the nature and developmental potentiality of tissue stem cells. In vivo plasticity of tissue stem cells is a new phenomena: hematopoietic stem cells (HSCs) have been reported to generate muscle and liver cells on transplantation, and perhaps also contribute to the brain of mice. Muscle stem cells contribute to the hematopoietic system, while neural stem cells contribute to all germ layers when introduced into mouse blastocysts and to multiple tissues following transplantation into adult mice. The origin of the contributing cells and the potentiality of individual stem cells (clonality) remain to established in many of the reported examples of in vivo plasticity. We hypothesize that key lineage-specific regulatory factors, which are normally involved in cell-type specification, may influence tissue stem cell plasticity. Recent in vitro experiments reveal that gain or loss of such factors may lead to retrograde cell differentiation or transdifferentiation. The experimental plan in this RFA application is designed to test the role of such factors in stem cell plasticity and how specific environmental niches may influence in vivo plasticity. Aim 1 will establish the in vivo developmental potential of a hematopoietic committed stem cell population from in vitro differentiated embryonic stem (ES) cells and mouse yolk sac, and also the influence of loss of hematopoietic or muscle regulatory factors on observed plasticity. The clonality of contributing stem cells will be determined by single cell injection and/or by DNA tagging methods. Aim 2 will test the possible involvement of bone marrow colonization or hematopoietic potential in plasticity by inactivating hematopoietic regulatory genes conditionally in HSCs or muscle stem cells. Aim 3 will assess whether expression of a hematopoietic (SCL/tal-1) or myogenic (MyoD) regulatory gene alters in vivo HSC or muscle stem cell plasticity. Aim 4 will evaluate the effects of hematopoietic or muscle regulatory factors on the developmental potential of mesenchymal or neural stem cells. The various approaches used in this work should provide a mechanistic basis for tissue stem cell plasticity, and offer the opportunity in the future to channel differentiation along specific pathways in a directed manner. These strategies may facilitate cell and gene transfer therapies in the future.
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0.909 |
2004 — 2013 |
Orkin, Stuart H |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Gfi-Proteins in Hematopoietic Development @ Dana-Farber Cancer Inst
DESCRIPTION (provided by applicant): All blood cells are derived from rare hematopoietic stem cells (HSCs) that reside in the bone marrow in the adult. Several transcription factors are critical for the formation and subsequent function of HSCs, and for the development of specific blood lineages. Study of the molecular mechanisms underlying blood cell specification and function has contributed immeasurably to our understanding of mammalian development, stem cell biology, and hematopoietic malignancies. The Growth Factor Independent (Gfi)-genes, Gfi-1 and Gfi-1b, are essential for various aspects of blood cell development and function. Gfi-1 is required for functional integrity of HSCs;without Gfi-1, HSCs proliferate excessively and lack self-renewal activity. Subsequently, Gfi-1 is important for the choice between neutrophilic and monocytic lineages, differentiation of neutrophils, and also for proper lymphoid development. Gfi-1b is required for normal erythroid and megakaryocytic cell maturation. Although much has been learned, important questions remain unresolved. The overall goal of this proposal is to define the mechanisms by which the Gfi proteins function in both HSCs and specific lineages, as this will be the most direct route to identifying the pathways used to sustain HSCs and also promote cellular maturation, rather than malignant transformation. The principles gained from the proposed studies should be readily applicable to other nuclear regulators central to the blood system and to factors employed in other organ systems. Aim 1 focuses on genetic experiments designed to determine the contribution of Gfi-1b to the formation and/or function of HSCs. Conditional knockouts of Gfi-1 and Gfi-1b in the mouse will be combined, and the effects of combined gene loss on development of the hematopoietic system and on the survival, proliferation, and self-renewal of HSCs in the adult will be determined. A systematic genomic approach will be developed to identify the critical gene targets regulated by the Gfi proteins in HSCs. Aim 2 centers on biochemical mechanisms of transcriptional repression by the Gfi proteins. Work in this laboratory has identified a repressor complex recruited to gene targets by the Gfi proteins. This complex includes the histone demethylase LSD1. Further work will be directed to elucidation of the details of the action of the repressor complex at target genes, and the roles of LSD1 in HSCs and specific hematopoietic lineages. Aim 3 probes a potential connection between Gfi proteins and the regulation of the micro RNA-21 gene locus. Preliminary work indicates that the Gfi proteins occupy chromatin within the miR-21 locus and miR-21 levels are elevated in Gfi-1 deficiency. To test the possible connection in a formal genetic manner in vivo, the requirement for miR-21 in hematopoietic development will be assessed in the context of a conditional mouse mutant at the miR-21 locus, a new mouse strain that is already on hand in this laboratory. If, as suggested, miR-21 participates in control of HSC function or lineage specification, it will provide a new avenue to pursue in development of the blood system. Project Narrative: How blood stem cells and different types of blood cells are programmed at the biochemical and genetic levels is important to our understanding of normal blood cell control, host defense against infection, the properties of adult stem cells, and how cancer is forestalled. The proposed project focuses on mechanisms by which one small family of gene products is critical to blood cell development and function. One long-term outcome of the findings of this work may be improved methods for expansion of blood stem cells, an advance that would facilitate many treatments based on bone marrow transplantation.
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0.909 |
2005 — 2008 |
Orkin, Stuart H |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Systems Analysis of Cancer Pathways in Mouse Models @ Dana-Farber Cancer Institute
[unreadable] DESCRIPTION (provided by applicant): [unreadable] Human cancer is comprised of a broad spectrum of phenotypes, based in part on the tissue of origin of the tumor. While cancer phenotypes are diverse, cancer biology has converged on shared pathways and molecular mechanisms of transformation among all tumor types. A multidisciplinary approach to defining promising molecular targets in selected pathways will utilize sophisticated mouse models in combination with bioinformatic integration of high throughput data from systems technology in order to drive discovery. [unreadable] [unreadable] Three established investigators Gilliland, Korsmeyer and Orkin, committed to mouse models of human cancer, are thematically aligned in this MMHCC proposal by the shared belief that interrogating mouse genetic models of cancer pathways will define unanticipated targets. Multiple shared interests are noted in each project at the intersections of tyrosine kinase, cell death, transcription and tumor suppressor pathways of oncogenesis. Existing or newly developed mouse models will be validated as accurate models of human cancer. The unique component of this application is to use genome wide techniques to further probe these models in order to identify resulting networks of genes and proteins that will provide new targets. Multiple high throughput assay systems will be developed within the context of the Center for Systems Biology (CSB) at DFCI. Marc Vidal, a leader in the emerging field of systems biology and a full participant of the applicant group, will enable transcriptome, proteome-interactome, and phenome profiles to create correlation maps, representing functional gene networks. The goal of this MMHCC proposal is to use these systems approaches to identify and then credential the most promising molecular targets within each cancer pathway. [unreadable] [unreadable] All investigators are committed to sharing resources and data with other members of the MMHCC and to the broader scientific community. [unreadable] [unreadable]
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0.909 |
2006 — 2010 |
Orkin, Stuart H |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Modeling Childhood Tel-Aml1 (Runx1) @ Dana-Farber Cancer Institute |
0.909 |
2009 — 2013 |
Orkin, Stuart H |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Exploiting Mouse Models of Pediatric Cancers and Epigenetics For Therapy @ Dana-Farber Cancer Inst
DESCRIPTION (provided by applicant): This UOl application brings together three Principal Investigators (Drs. Orkin, Armstrong, and Roberts) to exploit genetically engineered mouse models of devastating human pediatric cancers for the development of new therapeutic avenues. A common theme in these projects is understanding the role of epigenetics in cancer initiation and/or progression. In Project 1, "New approaches to osteosarcoma", the involvement of the polycomb repressive complex PRC2, which is overactive in many malignancies as well as in the mouse model of osteosarcoma, will be addressed by a multidisciplinary and integrated biochemical and genetic strategies. In parallel, efforts will be directed toward high-throughput screens to identify agents that induce differentiation of osteosarcoma cells or selectively kill cells deficient in both p53 and Rb (as in the case of this cancer). Project 2, "Epigenetic programs in leukemia development and drug response", will focus on the roles of DNA methylation and PRC2 in leukemias due to translocations involving the MLL locus. In addition, efforts will concentrate on high-throughput screening to identify inhibitors of D0T1L, the H3K79 histone methyltransferase associated with MLL-fusion proteins. Project 3, "Epigenetics in cancer initiation and progression: from mechanism to therapy", focuses on malignancies due to SNF5 inactivation, as these appear to be "epigenetically driven" and without evident somatic mutations. The interactions between SNF5 and MLL or PRC2 will be tested genetically, and thereafter drugs that target epigenetic pathways will be tested for efficacy in SNF5-deficinet cancer in the mouse. This U01 program is highly integrated as the mouse models affecting epigenetic pathways are shared among the projects. In addition to providing a highly interactive framework, this integration will allow for identification of features that are either common or specific for these malignancies.
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0.909 |
2009 — 2010 |
Orkin, Stuart H |
RC2Activity Code Description: To support high impact ideas that may lay the foundation for new fields of investigation; accelerate breakthroughs; stimulate early and applied research on cutting-edge technologies; foster new approaches to improve the interactions among multi- and interdisciplinary research teams; or, advance the research enterprise in a way that could stimulate future growth and investments and advance public health and health care delivery. This activity code could support either a specific research question or propose the creation of a unique infrastructure/resource designed to accelerate scientific progress in the future. |
Extending Gwas At the Bcl11a Locus to Novel Therapeutics For Hbf Induction @ Dana-Farber Cancer Inst
DESCRIPTION (provided by applicant): The goal of the proposed work is the development of novel approaches to the stimulation of fetal hemoglobin (HbF) production in red blood cells of adults. HbF is a known modifier of the severity of the major hemoglobin disorders, sickle cell anemia and beta-thalassemia. These diseases affect numerous individuals worldwide. As an important mission of the NHLBI is improved treatment of these conditions, the goal of the proposed work should be of high priority. Recent work has demonstrated that the repressor protein BCL11A is a major silencer of HbF expression in adult red cell precursors. The BCL11A gene was identified as a candidate regulator through genome-wide association studies (GWAS). The project has interrelated goals that will serve to validate BCL11A as a therapeutic target for HbF induction. First, the mechanism by which single nucleotide polymorphisms (SNPs) in the BCL11A gene influence the expression of BCL11A itself will be examined. This will demonstrate HOW SNPs control the locus. Second, experiments will be employed to assess the specificity of BCL11A as a regulator of HbF. Specifically;the gene expression profile of adult erythroid cells in which BCL11A expression is knocked-down will be determined and compared with the genomic chromatin occupancy of BCL11A. These experiments will define the number of proteins other than HbF that are affected by BCL11A knock-down and also potential "off-target" effects of BCL11A inhibition in erythroid cells. Third, approaches to therapeutic modulation of BCL11A expression or function will be explored. These studies will include highthroughput screening for small molecules or drugs that mimic the knock-down of BCL11A in erythroid cells, the development of engineered zinc finger proteins designed to inactivate the BCL11A gene, and testing of stabilized helical peptides that might interfere with BCL11A function. These efforts should establish experimental platforms that will facilitate the identification and validation of new therapeutics agents for subsequent clinical trials in patients. PUBLIC HEALTH RELEVANCE: Inherited disorders of hemoglobin (sickle cell disease and the thalassemias) are anemias that adversely affect the health of countless individuals worldwide. As maintenance of a form of hemoglobin that is expressed prior to birth, called fetal hemoglobin (HbF), in the adult lessens the severity of these conditions, reactivation of HbF in adult type red blood cells is an important therapeutic goal. The proposed research focuses on how to interfere with the major silencer of HbF, a recently identified protein BCL11A, in an effort to develop new treatment for inherited anemias.
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0.909 |
2009 — 2016 |
Orkin, Stuart H |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Research Training in Pediatric Oncology @ Dana-Farber Cancer Inst
DESCRIPTION (provided by applicant): This is a competitive renewal application for training grant support in pediatric oncology. The goal of this T32 program is to train physicians who will be the future academic leaders in basic and/or clinical pediatric oncology research and who will work to reduce the burden of cancer in the pediatric population. To accomplish this goal we have engaged a diverse and outstanding training faculty that embraces multiple areas of basic (wet bench), translational and clinical research. This experienced and highly accomplished group includes members of the Department of Pediatric Oncology at the Dana-Farber Cancer Institute (DFCI), the Division of Pediatric Hematology/Oncology at Boston Children's Hospital (BCH), and additional components of the Harvard Medical School (HMS). Particular emphasis is placed on close mentorship of trainees in the selection of mentors and in on-going oversight during their research. The T32 program provides training in oncology research at the postdoctoral level for 8 trainees, selected from the combined DFCI-BCH pediatric hematology/oncology fellowship program, who are in their second, third and fourth years of training. The program is committed to identifying and supporting the most promising fellows, including minority candidates. Over the past 45 years the DFCI-BCH fellowship program has trained over 200 individuals, many of whom are leaders of academic pediatric hematology/oncology programs. Continued T32 support will ensure the training of investigational pediatric oncologists, whose research will contribute immeasurably to the understanding and management of childhood cancers.
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0.909 |
2014 — 2018 |
Orkin, Stuart H Yuan, Guo-Cheng [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Systems Biology Analysis of Human Erythropoiesis @ Dana-Farber Cancer Inst
DESCRIPTION (provided by applicant): Erythropoiesis is a fundamental process in vertebrate animals and has long served as a paradigm for molecular investigations of developmental regulation. It has been well established that a small number of transcription factors, also known as master regulators, play an essential role in the maintenance of cell-identity and/or regulate the cell differentiation process. However, it is not fully elucidated how they work in combination with each other or various cofactors, particularly at different developmental stages. Since there are at least a thousand transcriptional regulators in mammals, the number of possible combinations is astronomical. Using experimental methods alone to dissect such complexity remains a daunting task as it demands prohibitively high cost and labor. To overcome this challenge, we propose a systems biology approach to be carried out by a team of experienced experimental and computational biologists. Using human primary erythroid precursor cells as the model system, we will generate extensive experimental data by genomic, epigenomic, and transcriptomic profiling, develop data-integrative and predictive computational methods, and perturb the systems by disrupting the normal regulatory activities. Our preliminary work has identified important regulatory network differences between adult and fetal erythroid precursors and suggested that collaboration between master regulators and cofactors plays an important role in driving developmental stage-specific transcriptional changes through acting upon enhancer elements. This will be extended by focusing on the following specific aims: (1) Predict and validate the developmental stage-specific gene regulatory networks in human primary erythroid precursors by integrating genomic and epigenomic data-types; (2) Perturb the gene regulatory networks using molecular and genetic experiments and further integrate such information to refine our network model; (3) Characterize the role of genetic variants influencing chromatin state, gene expression, and erythroid traits. In the end our results will greatly expand our current mechanistic understanding of combinatorial control in establishing cell-type and developmental stage-specificity and provide functional insights into erythroid trait- associated genetic variants.
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0.909 |