1994 — 1998 |
Cox, Adrienne D |
R29Activity Code Description: Undocumented code - click on the grant title for more information. |
Prenylation, Membrane Association, and Ras Transformatio @ University of North Carolina Chapel Hill
Despite our considerable knowledge of ras protein structure and biochemistry, we remain ignorant both of the precise biological function of normal ras proteins in normal cell growth and of the mechanism whereby oncogenic ras proteins trigger the aberrant growth of malignant cells. The recent observation that the posttranslational modification of ras proteins by a farnesyl isoprenoid (an essential intermediate in cholesterol biosynthesis) is critical for ras membrane association and transforming activity has prompted two new directions for ras studies: 1) specifically blocking the farnesyl modification of ras proteins as a novel method of rational drug design for cancer treatment, and 2) determining the significance of this lipid modification for normal and oncogenic ras biological activities. The experimental studies in this proposal are based on the recent observations that the substitution of the farnesyl isoprenoid on normal ras by a geranylgeranyl isoprenoid gave rise to a new class of dominant inhibitory ras mutant protein, whereas the substitution of the fatty acid myristate gave rise to a transforming protein. Either of these lipids can promote the membrane association and biological function of oncogenic ras proteins. Therefore, although membrane association is critical for ras function, normal and oncogenic ras proteins apparently possess different requirements for this association that may reflect their regulation of distinctly different mitogenic signal transduction pathways. The specific aims of this proposal are to determine (1) the role of protein prenylation in the biological activity of normal and oncogenic ras proteins, (2) the role of plasma membrane association in ras biological activity and whether this role differs for normal and oncogenic proteins, (3) to determine the basis for specific modification of proteins by specific types of lipids (isoprenoids versus fatty acids), and (4) whether the particular properties of lipid modification and subcellular location of a potential new oncogene protein, TC21, are shared with ras. These aims will be approached by comparing the biochemistry and biology of authentically farnesylated ras to mutant forms of ras that modified by heterologous lipids. These studies should contribute significantly to understanding the biochemical function of normal and oncogenic ras proteins and provide an important foundation for understanding the contribution of different lipid modifications to the function of other proteins, including src, the heterotrimeric G proteins, and ras-related proteins, that regulate diverse normal cellular processes.
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1 |
1998 — 2000 |
Cox, Adrienne 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. |
Mechanism of Fti Action and K-Ras Inhibition @ University of North Carolina Chapel Hill
(adapted from the investigator's abstract) Farnesyltransferase (FTase) inhibitors (FTIs) block a lipid modification critical for Ras membrane association and biological function, and easily inhibit H-Ras transforming activity in vitro and in animal models. Therefore, FTIs are under intense investigation as highly promising potential anti-cancer therapeutic agents. However, recent developments have made clear that the mechanism of FTI action is unexpectedly complex and not understood, although it certainly includes, although it certainly includes inhibition of FTase. Among the complexities are the findings that the excellent and straightforward results with H-Ras cannot be extrapolated to K-Ras; that K-Ras, the most commonly mutated form of Ras in human tumors, is highly resistant to FTI action; that FTI inhibition of transformation can be unlinked from inhibition of K-ras processing; and that Ras mutation status is not predictive for FTI sensitivity. There is general agreement that a likely explanation for some of these findings is the existence of critically important but as yet unidentified non-Ras targets of FTI action. However, both the academic and the pharmaceutic research communities are deeply divided over the significance and possible explanations for (and, therefore, of methods to overcome) the unexpectedly high resistance of K-Ras to FTIs. The existence and nature of this resistance has important implication, both for our understanding of the role and mechanism of action of the two different farnesylated Ras proteins in cellular transformation and for future successful drug design. The overall goals of this proposal are, therefore, to determine the basis for K-Ras resistance to FTI action and to determine the mechanism of FTI inhibition of transformation. To accomplish these goals, we propose to determine the relative contributions to FTI resistance of the high affinity of K-Ras for FTase and of possible alternative prenylation of K- Ras in human tumor cells; to compare the relative ability of unprocessed forms of H-, N-, and K-Ras to act as dominant negatives to block oncogenic Ras transformation; and to identify other physiologically important farnesylated targets for FTIs. The results of these experiments will provide further insight into the unexpectedly complex mechanisms of Ras processing and transformation and will provide fruitful directions for improvement in FTIs, as well as novel targets for drug design.
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1 |
2004 — 2008 |
Cox, Adrienne 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. |
Protein Prenylation, Oncogenesis and Novel Therapeutics @ University of North Carolina Chapel Hill
[unreadable] DESCRIPTION (provided by applicant): A major goal of our research has been the delineation of the role of protein isoprenylation in facilitating Ras and Rhc GTPase-mediated oncogenesis. From these studies, three major themes have emerged. First, the aberrant activation of Ras and Rho GTPase function contributes significantly to many facets of human oncogenesis. Second, while it was initially believed that isoprenoid lipid modification of proteins served simply as hydrophobic, nonspecific membrane-targeting lipid "glues", we now appreciate that isoprenylation, together with other sequence elements and lipid modifications, dictate a complex spectrum of dynamic membrane interactions that endow otherwise highly related GTPases with strikingly divergent biological roles. Third, since Ras and Rho GTPase membrane association and function are critically dependent on isoprenoid modification, pharmacologic inhibition of protein prenylation may be an effective approach for cancer treatment. Inhibitors of the enzymes that catalyze the isoprenylation of Ras and Rho GTPases have been developed as novel, target-based therapies. In particular, inhibitors (FTIs) of the enzyme farnesyl transferase (FTase) that modifies Ras proteins have shown remarkable anti-tumor activity in preclinical models and are currently under phase II-III clinical evaluation. Surprisingly, it is now accepted that the anti-tumor activity of FTIs is not due to Ras inhibition. Instead, the critical targets of FTIs are thought to be other FTase substrates. Defining these critical FTI targets will be crucial for the successful clinical development of FTIs. We propose four specific aims that extend from these three themes. First, we will define the novel mechanism by which the C-terminal sequences of the Cdc42-related proteins, Wrch-1 and Wrch-2/Chp, dictate membrane association and functional diversity from Cdc42. Unexpectedly, these two Rho GTPases are not substrates for either the FTase or GGTase I enzyme that isoprenylates the other Ras and Rho GTPases. Second, we will determine whether the farnesylated GTPase Rheb, recently implicated in oncogenesis by activation of the mTOR/S6 kinase pathway, is targeted by FTIs. Third, we will determine whether FTI-mediated loss of the farnesylated, Ras-related tumor suppressor proteins NOEY2/ARHI and Rig/Di-Ras define a potentially deleterious consequence of FTI therapy. Finally, we will determine whether the PRL protein tyrosine phosphatases, involved in promoting tumor cell invasion and metastasis, are important targets of FTI antitumor activity. [unreadable] [unreadable]
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1 |
2005 |
Cox, Adrienne D |
U19Activity Code Description: To support a research program of multiple projects directed toward a specific major objective, basic theme or program goal, requiring a broadly based, multidisciplinary and often long-term approach. A cooperative agreement research program generally involves the organized efforts of large groups, members of which are conducting research projects designed to elucidate the various aspects of a specific objective. Substantial Federal programmatic staff involvement is intended to assist investigators during performance of the research activities, as defined in the terms and conditions of award. The investigators have primary authorities and responsibilities to define research objectives and approaches, and to plan, conduct, analyze, and publish results, interpretations and conclusions of their studies. Each research project is usually under the leadership of an established investigator in an area representing his/her special interest and competencies. Each project supported through this mechanism should contribute to or be directly related to the common theme of the total research effort. The award can provide support for certain basic shared resources, including clinical components, which facilitate the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence. |
Validation of Inhibitors of Rho Gtpases For Cancer Treatment @ H. Lee Moffitt Cancer Ctr &Res Inst |
0.916 |
2006 |
Cox, Adrienne D |
R13Activity Code Description: To support recipient sponsored and directed international, national or regional meetings, conferences and workshops. |
Regulation &Function of Small Gtpases @ Federation of Amer Soc For Exper Biology
[unreadable] DESCRIPTION (provided by applicant): The proposed conference, Regulation and Function of Small GTPases, will be the eighth in a series of FASEB summer research conferences devoted to the study of GTP-binding proteins that regulate normal cellular processes as diverse as proliferation, polarity, migration and gene expression, and that contribute to disease processes such as cancer. The conference will be held July 15-20, 2006, at the Vermont Academy in Saxtons River, Vermont. These conferences have provided a unique forum for addressing important questions of cell biology that are regulated by members of the Ras superfamily. Originally divided into sessions according to GTPase subfamily, these conferences are now arranged around biological themes to enhance the principal objective, which is to stimulate cross-pollination of ideas among a diverse group of cell and structural biologists and biochemists by bringing them together in an intimate setting to share the latest developments in their fields. There are 34 invited speakers from the United States, Europe and Japan, with additional short presentations to be selected from submitted abstracts. Special attention has been paid to inclusion of women, and of young and minority investigators. The 8 oral sessions and 4 poster sessions will be enhanced by informal interactions at the conference site to develop new ideas and collaborative relationships. [unreadable] [unreadable] [unreadable] [unreadable]
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0.913 |
2007 — 2008 |
Cox, Adrienne D |
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. |
Cell and Molocular Biology Training Grant @ University of North Carolina Chapel Hill
DESCRIPTION (provided by applicant): The University of North Carolina at Chapel Hill proposes to continue the training program in Cell and Molecular Biology (CMB). This program will train outstanding students in a broad interdisciplinary program focused on four major and related areas of research: 1) Nucleic acid biology, 2) dynamics of cell structure, 3) Signal Transduction, and 4) Regulation of Cell Growth and Differentiation. Preceptors come from eight departments in the School of Medicine or College of Arts and Sciences. The students will receive their Ph.D. degree in one of the participating departments or in one of three interdepartmental programs (Neurobiology, Toxicology, or Genetics). Students will take required courses in cell biology and molecular biology and a seminar course focusing on the evaluation of RO1 applications addressing questions consistent with the themes of the program. Students will also participate in CMB Discussion Group, a CMB Seminar Series and an annual research retreat. In addition to our focus on research and problem solving, we will provide career guidance and foster the development of excellent communication, mentoring and teaching skills. We will provide students with travel funds and a small research allowance to encourage and promote collaborative research. The overall goal is to help students view problems in cell and molecular biology from a broad perspective and to encourage them to apply a creative, multidisciplinary approach to solving these problems. Graduates of the CMB program at UNC-Chapel Hill will be prepared for careers in biomedical research and teaching and will be ready to tackle complex biological problems in the post-genome era.
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1 |
2015 — 2019 |
Cox, Adrienne D Der, Channing J. [⬀] |
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. |
Identification of Synthetic Lethal Interactors in Pancreatic Cancer @ Univ of North Carolina Chapel Hill
? DESCRIPTION (provided by applicant): The goal of research supported by this FOA is to identify targets whose inhibition would induce synthetic lethality in cancers dependent on the expression of mutant KRas alleles, with a focus on one or more of the four most frequently observed alleles...in one or more of the predominant mutant KRas-dependent cancers e.g., pancreas..., and utilizing advanced screens that go beyond the current screens in 2D tissue culture. To accomplish this goal, we have assembled a well-integrated team of five investigators at three institutions. Our team will apply three complementary and highly innovative advanced screens to identify and validate targets whose inhibition would induce synthetic lethality in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). Each of our screens differs substantially from those in previously published RNAi-based synthetic lethal screens. We will focus not only on K-Ras G12D and G12V but also on G12R, the third most frequent KRAS mutation in PDAC and one whose properties we believe differ from those of other G12 mutants. We propose three specific aims: (1) a robust chemical library screen to convert pharmacologic inhibitors of K-Ras effector signaling from cytostatic to cytotoxic activities; (2) a focused genetic screen to identify cancer signaling pathway components whose activation overcomes addiction to mutant K-Ras; and (3) an unbiased, genome-wide gain-of-function insertional mutagenesis screen to identify genes whose overexpression overcomes addiction to mutant KRAS. Aim 1 will use a powerful chemical library screen (Drug Sensitivity and Resistance Testing, DSRT) of compounds selected specifically to allow rapid clinical transition of positive results. Aims 2 and 3 will employ complementary innovative gain-of-function genetic screens. Aim 2 will take a signaling-centric approach (Cancer Toolkit) shown in preliminary data to be able to identify both known and unknown mechanisms of inhibitor resistance, whereas Aim 3 will apply a genome-wide unbiased approach (CDt/MS) that is mass spectrometry-based and uniquely reads out at the protein level, thereby enabling a cheaper, faster and more informative process than conventional functional genomic screens. Aims 1 and 2 share a signaling focus, whereas Aims 2 and 3 share a conceptual theme. We will utilize low passage KRAS-mutant pancreatic cancer patient-derived xenograft (PDX)-derived cell lines throughout our studies. While the initial Aim 1 screens will be done in conventional high throughput 2D assays, validation of the hits will be done in 3D culture models including pancreatic organoids. Aim 2 and 3 screens will be done in both 2D and 3D culture as well as in vivo in tumor-bearing mice, and hits will be validated in 2D and 3D culture. The top hits from Aims 1-3 will then be further validated in PDX orthotopic pancreatic cancer models. We will apply pathway and network analysis, and expect to find significant overlap of important hits among the three screening approaches. Information from each of these strategies will be integrated across all platforms to identify the best synthetic lethal targets for pharmacologic inhibition and induction of cytotoxicity in KRAS-mutant pancreatic cancer cells.
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0.988 |
2016 — 2021 |
Cox, Adrienne D |
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. |
Cancer Cell Biology Training Program @ Univ of North Carolina Chapel Hill
ABSTRACT This application seeks continuation of our T32 Cancer Cell Biology Training Program (CCBTP), now in its 19th year. This exclusively predoctoral training program, together with the long-standing exclusively postdoctoral Integrated Training in Cancer Model Systems (ITCMS) T32, comprise the training component of the Lineberger Comprehensive Cancer Center (LCCC) at UNC-Chapel Hill. LCCC is one of only 45 NCI-designated Comprehensive Cancer Centers. The CCTP premise is that cancer cell biology is a distinct, interdisciplinary biomedical science that encompasses experimental approaches and didactic knowledge from fields as diverse as biochemistry, cell biology, epidemiology, genetics, immunology, microbiology, molecular biology, pathology, pharmacology, physiology and toxicology. The CCBTP mission has been, and continues to be, training the next generation of basic and translational cancer biologists. Since ours is not a degree-granting program, we seek to provide our students with unique opportunities beyond their departmental requirements. In this renewal application, the CCBTP seeks to build on its past success, while also recognizing that the landscape of cancer research and training has entered a new era of very dynamic change. With the approach of precision medicine, and the genomic era of cancer research continuing at warp speed, these are now some of the best of times for cancer research. Conversely, these are also challenging times. We are faced with information overload and must ensure that our trainees can leverage this information to advance their own research studies. Grant funding continues to challenge the research community. Issues of reproducibility dog this and other research fields. The pharmaceutical industry is no longer able to sustain its own research capabilities, changing the dynamics between industry and academia. To keep the CCBTP program fresh and to address the needs of future cancer biology trainees, we have critically evaluated the program and remodeled some aspects to keep abreast of this changing landscape. The core mission remains to ensure that we provide the best training for our cancer biology students. We also now focus on preparing our trainees for both academic and non-academic careers. In the past cycle, we have added novel interactions with faculty mentors, improved our diversity pipeline, and obtained enhanced institutional support. Going forward, in addition to our continued emphasis on translational cancer biology, we will provide our trainees with new opportunities to develop their knowledge of state-of-the-art methodologies to profile and dissect the cancer genome, bioinformatics and computational biology, the emerging areas of immunotherapy and epigenetics, the best model systems to study cancer, and reproducibility in research. The CCBTP serves a vital role in the mission of training to support the pipeline of future cancer biologists, preparing them to serve leading roles in the NCI Cancer Moonshot Initiative, and to accelerate progress in the prevention, diagnosis and treatment of cancer.
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0.988 |
2016 — 2020 |
Cox, Adrienne 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. |
Project 3: Mechanisms and Therapeutic Targeting of Nras in Melanoma @ Univ of North Carolina Chapel Hill
ABSTRACT Much remains to be learned about how RAS isoforms differ functionally from each other, and about the impact of specific mutations on each RAS protein. NRAS-mutant melanoma represents both a critical unmet need in terms of efficacious therapeutic options and also an outstanding opportunity to elucidate these functional differences. Although KRAS is the predominant RAS isoform mutated in cancers overall, NRAS is the predominant RAS isoform mutated in malignant melanoma, and whereas mutations at codon 61 are rare in KRAS, they predominate in NRAS. Project 2 has recently demonstrated that Nras Q61R but not G12D could drive melanoma formation in Ink4a-deficient mice. These provocative findings indicate that NRAS Q61R and G12D must activate distinct effectors, and/or activate effectors in a distinct manner. Given the preferential occurrence of NRAS Q61 mutations in melanoma, we propose studies to elucidate the signaling mechanisms that distinguish the roles of Q61- versus G12-mutant NRAS in driving these cancers. We hypothesize that there are structural, biochemical and biological properties distinct from those of the more common G12-mutant KRAS proteins found in lung, colorectal and pancreatic carcinomas. We have also identified an unexpected requirement for both KRAS and HRAS WT forms in NRAS-mutant melanomas. We will investigate effector signaling mechanisms driven by different NRAS mutants, define the requirements for WT isoforms, and leverage both candidate- and unbiased methodologies to identify targets that can lead to novel combination therapies for effective treatment of NRAS-driven melanomas. To address our goals, we propose three aims. In Aim 1, we will elucidate known and unknown effector signaling pathways downstream of cellular NRAS mutated at codon 61 versus codon 12. This Aim will be performed in close collaboration with Project 2, which will focus on structural and biochemical differences in the same panel of NRAS mutants. Projects 1 and 4 will also examine some of the cellular and tumorigenic phenotypes of the same mutations in different RAS isoforms. In Aim 2, we will characterize the requirement for WT RAS isoforms, and determine functional differences in effectors and signaling networks, as well as in transformed growth properties. In Aim 3, we will determine whether the same mechanisms that overcome melanoma addiction to mutant NRAS also overcome dependency on WT RAS isoforms. To do this, we will first interrogate YAP, known to be capable of rescuing addiction to mutant KRAS in carcinomas, and we will next perform a novel functional genetic screen to identify non-YAP mechanisms in an unbiased manner. Collectively, our studies will elucidate a better understanding of the neglected NRAS isoform, characterize functional distinctions among different NRAS mutations, determine relationships between WT and mutant NRAS-driven effector signaling pathways and networks, and identify new directions for novel therapeutic options in NRAS-driven melanoma.
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0.988 |