1994 — 1996 |
Licht, Jonathan D. |
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. |
Transcriptional Repression by the Wt-1 Protein @ Mount Sinai School of Medicine of Cuny
The application of molecular genetics to syndromes of familial cancer has led to the identification of recessive genes encoding possible tumor suppressing proteins. Elucidation of the function of such proteins will in the long term yield new insights into the pathogenesis and treatment of malignancy. Molecular analysis of the WAGR syndrome, in which children suffer from Wilms' tumors, often bilateral, at a young age, aniridia, genitourinary malformations and mental retardation, led to the molecular cloning of the WT-1 recessive tumor suppressor gene. WT-1 encodes a sequence specific DNA-binding repressor of gene transcription. Loss of repression by WT-1 may predispose to neoplasia and malformations by the deregulation of growth promoting genes. We hypothesize that WT-1 represses transcription through specific inhibitory contacts with components of the transcriptional machinery. Accordingly, we will characterize the mechanism of action of the WT-1 by determining its ability to repress transcription from a defined promoter in-vivo, using procedures similar to those we have used to characterize transcriptional repression by the Drosophila Kruppel protein. We will analyze the transcriptional effects of mutations of the WT-1 protein found in patients with the Denys-Drash syndrome and spontaneous Wilm's tumors, which we speculate to be dominant negative mutations of WT-1. We will reconstitute transcriptional repression by WT-1 in-vitro, in order to determine which phase of transcriptional initiation is blocked by the WT-1 protein. Collectively, these studies will yield insight into the molecular mechanism of a transcription factor whose alteration or deletion can lead to malignancy and malformations.
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0.946 |
1997 — 2000 |
Licht, Jonathan D. |
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. |
Transcriptional Repression by the Wti Protein @ Mount Sinai School of Medicine of Nyu
DESCRIPTION: (adapted from the investigator's abstract) The WT1 protein is a sequence-specific DNA-binding transcription factor with an critical role in normal kidney development and the pathogenesis of Wilms' tumor. During the initial funding period the investigators established that WT1 may act as an activator of transcription and that dominant negative forms of WT1 can block activation. The investigators further demonstrated that WT1 can self associate and proposed that non-DNA binding, dominant-negative forms of the WT1 protein shield or sequester wild-type WT1. However, the role of WTl multimerization in its normal function to activate or repress transcription is not clear. The ability of WT1 to activate or repress transcription depends on the nature of the expression vector used in co-transfection experiments. The investigators believe that WT1 is a default activator of transcription and under experimental conditions that deplete WT1 of essential co-factors for activation, WT1 will repress a target gene. Despite much study, the mechanism by which gene regulation is modulated by WT1 remains obscure and the nature of the transcriptional co-factors required for WT1 function is not yet known. In addition it is not known which transcriptional function of WT 1 is critical for its role in controlling differentiation and cellular growth. Tumor associated mutations in WT1 have been isolated in both its minimal activation domain and repression domain. They believe that these mutations interfere with critical protein-protein interactions of WT1 and may serve to genetically identify critical co-factors required for the action of the WT1 protein. During the initial term of this grant they found that WT1 can repress growth and induce epithelial-like differentiation of fibroblasts. This offers us a system in which to study the biological effects of tumor-associated and artificial mutations of WT 1. Such a system may also allow us to determine the biological importance of proteins that closely associate with WT1. Through these aims, by the end of the next period of funding, they will have a much more detailed understanding of the mechanism of action of WT1 in gene regulation, growth suppression and induction of differentiation. They hope to characterize the mechanism(s) by which WT1 represses target genes and identify proteins that interact with WT1 to modulate both its transcriptional and biological effects.
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0.949 |
2000 — 2002 |
Licht, Jonathan D. |
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. |
Convergent Functions of P53 and Brca1 in Gene Regulation @ Mount Sinai School of Medicine of Cuny
The tumor suppressor protein p53 is a transcription factor that has been implicated in the cellular response to DNA damage and mediates either growth arrest or apoptosis. The tumor suppressor BRCA1 is less well- characterized but over-expression of BRCA1 was shown to also alternatively lead to growth arrest or apoptosis p53 and BRCA1 have been shown to interact both physically and functionally. The research proposed in the application is designed to explore the details of p53 and BRCA1-dependent transcriptional activation and elucidate whether the interaction of these tumor suppressor proteins has biological relevance. Preliminary studies have identified two classes of p53 response elements by examining the effect of monoclonal antibody moAb421 on the sequence-specific DNA binding of p53 in electrophoretic mobility shift assays. Incubation with moAb421 enhances the binding of p53 to one set of response elements by inhibits binding to another set, suggesting that different conformations of p53 may interact with each subset of response elements. BRCA1 selectively enhances p53-dependent activation of one subset of sites. Our studies have also shown that the ATF1 transcription factor can interact with BRCA1 protein both physically and functionally and that BRCA1 can augment transcription through a cyclic AMP response element (CRE). Promoters have been identified which contain both a CRE and a p53 binding site. Thus, the proposed aims include experiments to: (1) Determine the significance of distinct subsets of p53 response elements classified by the differential effect of monoclonal antibody moAb421. (2) Determine how BRCA1 alters transcription through the CRE and characterize the interaction of BRCA1 with members of the ATF1 and CREB transcription factors. (3) Characterize the interaction of BRCA1 and p53 on genes that contain both a CRE and a p53 site. (4) Determine the role of BRCA1 and ATF1 in the p53- mediated response to DNA damage. As p53 is mutated in up to 30% of cases of breast cancer and the BRCA1 gene is responsible for approximately 50% of inherited breast cancer, it will be important to determine whether these two tumor suppressor proteins play convergent roles in gene expression involved in the cellular response to DNA damage as well as in the pathogenesis of breast cancer.
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0.946 |
2001 — 2005 |
Licht, Jonathan D. |
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. |
Sprouty, a Wt1 Target For Growth and Development @ Mount Sinai School of Medicine of Nyu
DESCRIPTION: (Adapted from the applicant's abstract) In this proposal we will characterize the expression of sprouty in renal development, murine development in general and in Wilm's tumors. We will characterize the mechanism of action of sprouty. Hence we will determine if sprouty is a growth inhibitor which may mediate some of the effects of WT1. We will determine at which steo in signaling through receptor tyrosine kinase sprouty acts. We then isolate partner proteins of spry which will lead to better idea of the molecular mechanism of sprouty. In order to determine the role of spry in normal and aberrant development we will determine in cell culture models and transgenic animals if engineered expression of spry interferes with normal renal morphogenesis. Finally to provide a critical role of sprouty as a target of WT1 important for renal development we will create knockout animals for sprouty one using conditiona cre-lox technology. Through these studies we will characterize an exciting molecule involved isgnal transduction and development. Spry may present a target for future strategies against Wilm's tumor, other malignancies and renal disorder such as polycystic kidney disease.
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0.949 |
2009 — 2013 |
Licht, Jonathan |
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. |
Transcriptional Functions and Targets of the Mmset Protein of T(4:14) Myeloma @ Northwestern University At Chicago
DESCRIPTION (provided by applicant): Multiple myeloma (MM) represents the malignant transformation of plasma cells, differentiated, post-germinal center B-cells adapted for the production of large quantities of antibody. Multiple myeloma is one of the commonest hematological malignancies and despite the advent of several new therapies such as proteosome inhibitors and thalidomide and the use of stem cell transplant consolidation, the disease is incurable with a median survival of about three years. The pathogenesis of this disease for many years was quite obscure, but over the past decade progress has been made based upon the characterization of consistent chromosomal translocations involving the immunoglobulin heavy chain (IgH). These translocations implicate particular genes in the pathogenesis of myeloma. MMSET (MULTIPLE MYELOMA SET DOMAIN) gene was identified at the breakpoint of the t(4;14) translocation, present in ~15% of multiple myeloma. This gene rearrangement leads to the transcriptional activation and overexpression of the FGFR3 gene and the MMSET gene, however in about 15% of cases only MMSET and not FGFR3 is overexpressed due to the rearrangement leading to the idea that deregulation of MMSET expression is central to the pathogenesis of this form of multiple myeloma. MMSET has a SET domain previously identified in histone methyl transferases and several other protein domains found in chromatin regulators. It has been confirmed that the MMSET protein is significantly overexpressed in myeloma cells harboring the t(4;14) translocation. The preliminary data indicates that MMSET has proprieties of a transcriptional co-factor, including localization to the nucleus, the ability to bind to sequence specific transcription factors including the zinc finger protein ZNF331 and transcriptional co-factors and histone deacetylases. In addition MMSET has histone methyl transferase activity which may be significantly different in terms of specificity when compared to other such proteins. These data lead to our overarching hypothesis that aberrant overexpression of MMSET leads to deregulated gene expression in B cells, contributing to the pathogenesis of myeloma. Our specific aims are: 1) To determine the transcriptional functions of MMSET, 2) To determine the biological activity of MMSET on Myeloma Cell Growth using gain of function and loss of function strategies, 3) To characterize the MMSET transcriptional complex and partner proteins for gene regulation, 4) To identify genes regulated by MMSET relevant to Multiple Myeloma. PUBLIC HEALTH RELEVANCE: MMSET protein is significantly overexpressed in myeloma cells harboring the t(4;14) translocation. These data lead to our overarching hypothesis that aberrant overexpression of MMSET leads to deregulated gene expression in B cells, contributing to the pathogenesis of myeloma.
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0.907 |