REGULATION OF P53 IN CERVICAL CARCINOMA BY HEAT/HYPOXIA
Amato J Giaccia, Professor And Director
Radiation Oncologystanford University
stanford, Ca 94305
Grant 3R01CA064489-03S1 from National Cancer Institute IRG: RAD
Project start date: 1996-05-03
Project end date: 2000-02-29
3R01CA064489-03S1 (1998): $36058
Sponsored Links Excellgen http://Excellgen.com
REGULATION OF P53 IN CERVICAL CARCINOMA BY HEAT/HYPOXIA
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 3R01CA064489-04S1 from National Cancer Institute IRG: RAD
Abstract: The normal fidelity of chromosome replication in untransformed cells is maintained by coordinately regulated cellular pathways that sense DNA alterations, modulate cell-cycle progression, and restore DNA integrity. Of these diverse cellular activities, the regulation of cell-cycle progression has the most profound effect on the chromosome stability of a cell exposed to adverse environmental conditions. Previous studies by us and other have demonstrated an increase in chromosome instability either by the deregulated expression of proto-oncogenes such as ras that accelerates cell proliferation or through the loss of negative growth regulators such as p53 and Rb that modulate a G1/S-phase transition. In addition to aberrant cell gene products, viral oncogene products such as the human papillomavirus E6 and E7 proteins are also able to increase genomic instability by reducing or eliminating a G1/S-phase checkpoint through inhibition of p53 and Rb, respectively. Oncogene overexpression is sufficient to rapidly (within a few cell divisions) enhance genomic instability. In contrast, abrogation of a cell-cycle checkpoint by the viral products E6 and E7 has a small effect on chromosome integrity in unperturbed cells. However, when E6 and E7 expressing cells are challenged by a growth restrictive stress or by exposure to DNA damaging agents, they become genomically unstable. Thus, the goals of this study are to use the human papillomavirus E6 and E7 genes as tools 1) to investigate the differences and similarities between the modulation of wild-type p53 activity by hypoxia vs ionizing radiation, and 2) to explore the mechanism of genomic instability and apoptosis induced by hypoxia. The results obtained from this study will give us new insights into how tumor specific physiological stresses such as hypoxia modulate viral oncogene products that have been implicated in the initiation of cervical carcinoma. The above proposed studies are predicted on two distinct differences we have found between p53 induction by DNA damaging agents and p53 induction by hypoxia. First, although hypoxia causes the accumulation of nuclear p53 DNA binding and transcriptional enhancing activity, the G1/S-phase block found only in wild-type p53 cell lines after ionizing radiation is found after hypoxia in both wild type and mutant p53 cell lines. Secondly, cells expressing the E6 gene from human papillomavirus (HPV type 16 or 18) fail to accumulate p53 in response to ionizing radiation and fail to induce a G1/S-phase checkpoint due to increased degradation of p53 by ubiquitination. In contrast, E6 expressing cells do increase their p53 levels when exposed to hypoxia, and induce a G1/S-phase checkpoint. These results indicate that the signal transduction pathway for growth arrest induced by hypoxia is distinct from the signal transduction pathway for growth arrest induced by ionizing radiation. We also present data to indicate that the induction of apoptosis by hypoxia is dependent on wild- type p53 activity and propose that hypoxia selects for cervical carcinomas that have lost their ability to undergo apoptosis, leading to a tumor that responds poorly to radiation or chemotherapy.
Keywords: carcinoma, cervix neoplasm, heat, hypoxia, neoplasm /cancer genetics, p53 gene /protein, DNA binding protein, DNA damage, DNA replication, biological signal transduction, chromosome, gene expression, gene induction /repression, genetic regulation, genome, ionizing radiation, oxygen tension, programmed cell death, protein biosynthesis, protein degradation, tumor suppressor gene, fluorescent in situ hybridization, gel mobility shift assay, human genetic material tag, human papillomavirus, tissue /cell culture
Project start date: 1996-05-03
Project end date: 2000-05-31
3R01CA064489-04S1 (1999): $9039
3R01CA064489-01A2S1 (1997): $7841
3R01CA064489-02S1 (1997): $39729
Grants awarded to Amato J Giaccia
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5R01CA088480-10 from National Cancer Institute
Abstract: The tumor microenvironment influences both therapeutic outcome and malignant progression. Previous studies from my laboratory have indicated that hypoxia induces apoptosis in oncogenically transformed cells in vitro, can act as a selective pressure for the expansion of transformed cells possessing diminished apoptotic potential, and co-localizes with apoptotic regions in tumors. The tumor suppressor protein p53 induces rapid apoptosis in response to oxygen concentrations that induce an S-phase arrest. Hypoxia-induced p53 is nuclear and associates with p53-response elements in target genes, such as mdm2 and p21. The cellular decision to use p53 transactivation or transrepression is mediated after the binding of p53 to the promoter by the stress, and is determined by the presence of co-activators or co-repressors. In contrast to p53-induced by DNAdamaging agents, hypoxia-induced p53 has primarily transrepression activity. Using extensive microarray analysis, we identified families of repressed targets of p53 that are involved in cell signaling, DNA repair, cell-cycle control and differentiation. Mutation analysis has determined that loss of transrepressor activity of p53 results in diminished apoptosis under hypoxic conditions. Mutation of residues 25,26 or 53,54 in the amino terminus of p53, that have previously been shown to inactivate p53-dependent transactivation, could still signal apoptosis under hypoxic conditions. However, mutation of all four residues completely abolished p53 dependent apoptosis as well as p53 dependent transrepression. This study defines a new role for the 53,54 residues of p53 regulating transrepression and suggests that 25,26 and 53,53 work in the same pathway to induce apoptosis through gene repression. Furthermore, p53 induced by both genotoxic as well as nongenotoxic stress is able to bind to the same promoters, but it is the stress that determines whether apoptosis is mediated by transcriptionally dependent or independent pathways. The critical hypothesis that we will be testing is that genotoxic and non-genotoxic stresses modulate gene activation and repression via p53´s association with chromatin. In this proposal, we will demonstrate the importance of gene repression by hypoxia in apoptosis and differentiation using in vivo derived models. We will investigate the importance of protein interactions with the amino terminus of p53 in regulating gene repression by hypoxia. We will test these hypotheses through a combination of genetic and biochemical approaches in cell lines and in mice
Keywords: API4; Activation, Gene; Address; Antioncogene Protein p53; Apoptosis; Apoptosis Inhibitor 4; Apoptosis Inhibitor Survivin; Apoptosis Pathway; Apoptotic; Assay; BALB/c; BIRC5; Baculoviral IAP Repeat-Containing 5 (Survivin); Baculoviral IAP Repeat-Containing Protein 5; Binding; Binding (Molecular Function); Bioassay; Biochemical; Biologic Assays; Biological; Biological Assay; Cell Communication and Signaling; Cell Cycle; Cell Cycle Control; Cell Cycle Regulation; Cell Cycle Regulation, Including Apoptosis; Cell Death, Programmed; Cell Division Cycle; Cell Line; Cell Lines, Strains; Cell Signaling; CellLine; Cellular Tumor Antigen P53; Chromatin; Classification; DNA Damage; DNA Damage Repair; DNA Injury; DNA Repair; Data; EF5; EPR-1; Exhibits; FLR; Failure (biologic function); Family; Funding; Gene Activation; Gene Combinations; Gene Down-Regulation; Gene Expression; Gene Library; Gene Targeting; Gene Transcription; Generalized Growth; Genes; Genes, p53; Genetic; Genetic Alteration; Genetic Change; Genetic Transcription; Genetic defect; Genotoxic Stress; Grant; Growth; Heterograft; Human; Human, General; Hypoxia; Hypoxic; IAP4; IT Systems; Immune; In Vitro; Inbred BALB C Mice; Individual; Information Systems; Information Technology Systems; Intracellular Communication and Signaling; Investigation; Investigators; Laboratories; Link; Malignant; Malignant - descriptor; Mammals, Mice; Man (Taxonomy); Man, Modern; Mediating; Mice; Mice, Inbred BALB C; Microarray Analysis; Microarray-Based Analysis; Modeling; Molecular Interaction; Molecules, Repressor; Mouse, BALB C; Murine; Mus; Mutate; Mutation; Mutation Analysis; Neoplasm Transplantation; Nuclear; O element; O2 element; Oncogene Activation; Oncoprotein p53; Outcome; Oxygen; Oxygen Deficiency; Oxygen measurement, partial pressure, arterial; P53; Pathway interactions; Phase; Phosphoprotein P53; Phosphoprotein pp53; Pressure; Pressure- physical agent; Programs (PT); Programs [Publication Type]; Promoter; Promoters (Genetics); Promotor; Promotor (Genetics); Protein TP53; Protein p53; Proteins; RNA Expression; Recruitment Activity; Regulation; Repression; Repressor Molecules; Research Personnel; Researchers; Resistance; Response Elements; Role; Series; Signal Transduction; Signal Transduction Systems; Signaling; Stress; Stress, Genotoxic; System; System, LOINC Axis 4; Systematics; Systems, Data; TP53; TP53 gene; TRP53; Targetings, Gene; Testing; Therapeutic; Tissue Growth; Trans-Activation (Genetics); Transactivation; Transcription; Transcription Repression; Transcription, Genetic; Transcriptional Repression; Transfection; Transplantation, Heterologous; Tumor Protein p53; Tumor Protein p53 Gene; Tumor Suppressor Proteins; Unscheduled DNA Synthesis; Work; Xenograft; Xenograft procedure; Xenotransplantation; arterial pO2; base; biological signal transduction; cell transformation; cultured cell line; experiment; experimental research; experimental study; failure; gene product; gene repression; genetic library; genome mutation; in vivo; microarray technology; mutant; ontogeny; oxygen tension; p53 Antigen; p53 Tumor Suppressor; pathway; pressure; programs; recruit; research study; resistant; response; social role; success; survivin; transformed cells; tumor; tumor growth; tumor suppressor; tumor transplant; tumor transplantation
Project start date: 2000-07-01
Project end date: 2010-04-30
Budget start date: 1-MAY-2009
Budget end date: 30-APR-2010
5R01CA088480-10 (2009): $314678
5R01CA088480-08 (2007): $314651
5R01CA088480-07 (2006): $324037
2R01CA088480-06 (2005): $333050
2R37CA088480-11 (2010): $334079
POSTDOCTORAL TRAINING IN THE RADIATION SCIENCES
Amato J Giaccia
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5T32CA121940-04 from National Cancer Institute
Abstract: The training of academic radiation oncologists and biologists has suffered nationwide from the paucity of formalized training programs. In this application we propose to bring together faculty associated with all three radiation oncology subspecialties (medicine, biology and physics) to establish an interdisciplinary postgraduate training program in radiation sciences. This two year program will accept two exceptional postdoctoral fellows and/or medical residents per year who are interested in an intensive research-based program. The goals of the training program are 1) To teach the trainees the theory concerning the physics governing the delivery of radiation, and the cellular biology governing its biologic effect. 2) To educate participants in the design and execution of cutting edge research in the radiation sciences. And 3) To gather together trainees from the fields of medicine, biology and physics so that they may develop a mutual appreciation for the many aspects of the study and treatment of patients with cancer. This is a particularly timely and relevant application because therapeutic radiation has become a mainstay in the treatment of many forms cancer. It is therefore imperative to develop a well trained cohort of professionals who will be responsible for the next generation of therapeutic advancements
Keywords: Radiation; Science; post-doctoral training; postdoctoral training; ray (radiation)
Project start date: 2007-09-01
Project end date: 2012-08-31
Budget start date: 1-SEP-2010
Budget end date: 31-AUG-2011
PFA/PA: PA-02-109
5T32CA121940-04 (2010): $225996
1T32CA121940-01A1 (2007): $109395
Cancer Etiology, Prevention, Detection, And Diagnosis
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 5T32CA009302-30 from National Cancer Institute IRG: NCI
Abstract: The Training Grant supports graduate students and postdoctoral fellows in the Cancer Biology Program at Stanford University. This program is interdisciplinary and is composed of faculty from both the School of Medicine and of Humanities and Sciences. The Principal Investigator on the training grant is also the Director of the program and Chairperson of a faculty Committee on Cancer Biology which reports to the University Committee Graduate Studies and to the Dean of the Medical School. The program provides research training leading to the Ph.D. degree in Cancer Biology, and research training for postdoctoral fellows in areas relevant to the molecular and cellular biology of cancer. Training for predoctoral students involves unit course requirements as well as specific course requirements. The latter include the molecular and cellular biology of cancer, basic biochemistry, advanced molecular biology, cell sciences and the responsible conduct of research. Completion of the Ph.D. requires completion of a qualifying exam, an oral defense, and submission of a written thesis. Trainees supported by the training grant are selected annually by the Committee on Cancer Biology from written applications by qualified candidates and from interviews conducted at Stanford. A total of 16 funded positions for predoctoral trainees are available each year. Funding on this training grant is provided for 4 academic years, after which students are supported by faculty preceptors for the duration of their training. The training grant also provides stipend support for 6 postdoctoral fellows per year. These positions are awarded for 2 years and are selected annually by the Committee on Cancer Biology from a pool of applications. The facilities for training consist primarily of research laboratories under the control of individual faculty preceptors in the Schools of Medicine and Humanities and Sciences, and include all common and core facilities in individual departments represented in these schools. The Cancer Biology Program maintains an office staffed by the Director s Administrator for the program.
Project start date: 1977-09-15
Project end date: 2007-06-30
5T32CA009302-30 (2006): $1074447
5T32CA009302-29 (2005): $1021980
Sponsored Links Excellgen http://Excellgen.com
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Abstract: The Program in Radiation Biology is focused on ways in which the effectiveness of radiotherapy can increase local tumor control and survival of cancer patients. Three different approaches are being pursued to achieve this goal 1) Development of pharmacologic and biologic agents to combine with radiotherapy and chemotherapy to improve local tumor control and prevent metastatic spread. 2) Development of new approaches and clinical trials to administer radiotherapy. 3) The identification of genetic determinants that influence the tumor response to radiation or the combination of chemotherapy and radiation using yeast and mammalian genetics. The research of program members has resulted in a series of important findings that include the regulation of stem cell differentiation by hypoxia, identifying a serum biomarker for tumor hypoxia, developing hypoxic specific cytotoxins for cancer therapy, identifying new genes that are essential for DNA repair and adaptation to stress, defining the role of p53 in global genomic DNA repair, generation of mouse models to dissect the role of p53 transactivation and p53 target genes in in vivo stress responses, the use of radiosurgery to treat pancreatic cancer, liver, lung and prostate cancer, and developing molecular and functional imaging techniques to direct the delivery of radiotherapy. The 23 program members representing the School of Medicine and Department of Biological Sciences in the School of Humanities and Sciences are highly motivated to develop new targeted therapeutics to combine with radiotherapy and are well supported by two program project grants and $4.3 million in NCI funding. During the last five years, the program members published 188 papers. With the support of the Cancer Center, the role of Radiation Biology in tumor immunity, stem cell recruitment and differentiation, and functional imaging will be further developed and expanded. In particular, the Cancer Center will greatly aid in translating many of the laboratorybased findings to increase the effectiveness of radiotherapy into the clinic
Keywords: Affect; Anaerobic Bacteria; Anti-Cancer Agents; Anti-Tumor Agents; Anti-Tumor Drugs; Antibodies; Antineoplastic Agents; Antineoplastic Drugs; Antineoplastics; Antiproliferative Agents; Antiproliferative Drugs; Apoptosis; Apoptosis Pathway; Area; Attention; Bacteria, Anaerobic; Benzotriazines; Blood Tests; Brain; Cancer Center; Cancer Drug; Cancer Radiotherapy; Cancer of Prostate; Cancerous; Cancers; Carcinoma of the Pancreas; Cell Cycle Checkpoint; Cell Death; Cell Death, Programmed; Cells; Chemotherapeutic Agents, Neoplastic Disease; Clinical Research; Clinical Study; Clinical Trials, Phase II; Clinical Trials, Phase III; Clostridium; Cytotoxin; DNA Damage Repair; DNA Repair; Dose; Drug Delivery; Drug Delivery Systems; Drug Precursors; Drug Targeting; Drug Targetings; Drugs; Effectiveness; Encephalon; Encephalons; Enzymes; Exocrine Pancreas Carcinoma; Family; Forecast of outcome; Functional Imaging; Future; Gastrointestinal Tract, Pancreas; Gene Expression; Generalized Growth; Genes; Genes, p53; Genetic Determinism; Genome; Genome Instability; Genomic Instability; Goals; Growth; HNSCC; Head and Neck; Head and Neck Carcinoma; Head and Neck Squamous Cell Carcinoma; Head and neck structure; Hematologic Tests; Hematological Tests; Hematology Testing; Hypoxia; Hypoxic; IMRT; Image; Intensity Modulated RT; Intensity Modulated Radiation Therapy; Intensity-Modulated Radiotherapy; Intermediary Metabolism; Lesion; Liver; Lung; METBL; Malignant Neoplasms; Malignant Pancreatic Neoplasm; Malignant Tumor; Malignant Tumor of the Prostate; Malignant neoplasm of pancreas; Malignant neoplasm of prostate; Malignant prostatic tumor; Medical center; Medication; Metabolic Processes; Metabolism; Methods and Techniques; Methods, Other; Necrosis; Necrotic; Nervous System, Brain; O element; O2 element; Organ; Oxides; Oxygen; Oxygen Deficiency; Oxygen measurement, partial pressure, arterial; P53; Pancreas; Pancreas Cancer; Pancreatic; Pancreatic Cancer; Pancreatic carcinoma; Pathway interactions; Patients; Pharmaceutic Preparations; Pharmaceutical Preparations; Phase 2 Clinical Trials; Phase 3 Clinical Trials; Phase I/II Trial; Phase II Clinical Trials; Phase III Clinical Trials; Physiologic Imaging; Physiology; Pro-Drugs; Prodrugs; Prognosis; Programs (PT); Programs [Publication Type]; Prostate CA; Prostate Cancer; Prostatic Cancer; Protocol; Protocols documentation; QOL; Quality of life; Radiation; Radiation Biology; Radiation Sensitivity; Radiation Surgery; Radiation Tolerance; Radiation therapy; Radioactive; Radiobiology; Radiosensitivity; Radiosurgery; Radiotherapeutics; Radiotherapy; Relapse; Research; Respiratory System, Lung; Role; SCCHN; Solid Neoplasm; Solid Tumor; Stereotactic External Beam Irradiation; Stereotactic Radiosurgery; Stereotaxic Radiosurgery; Stress; System; System, LOINC Axis 4; TP53; TP53 gene; TRP53; Techniques; Testing; Tissue Growth; Tumor Cell; Tumor Protein p53 Gene; Tumor-Specific Treatment Agents; Universities; Unscheduled DNA Synthesis; Yeasts; anaerobe; anticancer agent; anticancer drug; arterial pO2; base; biomarker; body system, hepatic; drug/agent; efficacy testing; genetic determinant; imaging; irradiation; malignancy; necrocytosis; neoplasm/cancer; neoplastic cell; new therapeutics; next generation therapeutics; novel; novel therapeutics; ontogeny; organ system, hepatic; outcome forecast; oxygen tension; pancreas carcinoma; pathway; phase 2 study; phase 2 trial; phase 3 study; phase 3 trial; phase II trial; phase III trial; programs; protocol, phase II; protocol, phase III; pulmonary; ray (radiation); response; social role; study, phase II; study, phase III; therapeutic development; transcription factor; tumor; tumor growth
Budget start date: 1-SEP-2009
Budget end date: 31-AUG-2011
3P30CA124435-03S2_0004 (2009): $601
5P30CA124435-03_0004 (2009): $20909
REGULATION OF P53 IN CERVICAL CARCINOMA BY HEAT/HYPOXIA
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 5R01CA064489-02 from National Cancer Institute IRG: RAD
Abstract: The normal fidelity of chromosome replication in untransformed cells is m5R01CA064489-04
Keywords: 1999
Project start date: 1996-05-03
Project end date: 2000-02-29
5R01CA064489-02 (1997): $189578
5R01CA064489-04 (1999): $205046
5R01CA064489-03 (1998): $197159
MOLECULAR CYTOGENETICS OF PROSTATE CANCER
Amato J Giaccia, Professor And Director
Radiation Oncologystanford University
stanford, Ca 94305
Grant 5R01CA058838-02 from National Cancer Institute IRG: PTHB
Abstract: The incidence of prostate cancer is rapidly overcoming all other cancers in men 50 years and older and is now the second leading cause of cancer deaths in men. Prostate cancer can be broadly classified into three forms latent, aggressive and metastatic. Each of these forms can be pathologically "staged" with respect to their anatomical location in or beyond the prostate and their degree of differentiation (Gleason´s grade). Since a tumor results from a series of chromosomal alterations which allow the cell to escape from the normal mechanisms which control its growth, then it would be a logical first step to identify the specific chromosomal changes which are associated with tumor development. However, a paucity of information exists on the genetic and molecular evolution of events which are responsible for prostate cancer. To date, most attempts at identifying karyotypic chromosomal rearrangements in prostate cancer biopsies have proven to be frustrating. In part this is due to the cellular growth characteristics of prostate cancers which can lie dormant for months before division. In addition to their slow growth rate, obtaining metaphases from prostate cancer biopsies also has the inherent problem of selection for rapidly growing cells, biasing the results to cells that may not be representative of the tumor. Therefore, to avoid the problems associated with conventional cytogenetic banding techniques, we intend to apply the techniques of fluorescent in situ hybridization combine with premature chromosome condensation to karyotype prostate cancer cells from biopsies. With this new approach, the need to grow cells for even short periods of time can be avoided, and the population of cells to be analyzed is only limited by the size of the biopsy. this will allow direct analysis of tumor cells in situ, a goal that is difficult to achieve by conventional cytogenetic analysis because of the requirement for cell cultures to obtain metaphase chromosomes for banding analysis. We will use chromosome specific DNA libraries as probes to detect gross structural aberrations for each human chromosome; chromosome specific repetitive probes such as alpha satellite DNA (centromere specific probes) to detect numerical chromosome changes; and cosmid or YAC (Yeast Artificial Chromosomes) probes specific for microchromosomal regions that have putatively been implicated in prostate cancer such as 7q24 and 10q24 as well as those we will find during the course of this study. The ultimate goal of this study is to identify chromosome alterations which are stage or differentiation specific for prostate cancer. This goal has not yet been achieved for prostate cancer, mainly due to the problems of obtaining sufficient material for cytogenetic analysis. In addition, knowledge of known cytogenetic changes in prostate cancers will be useful both for prognosis and detection of minimal residual disease
Keywords: chromosome aberration, cytogenetics, genetic technique, karyotype, prostate neoplasm fluorescence, gene rearrangement, hybrid cell, in situ hybridization, metastasis, neoplasm /cancer classification /staging, neoplasm /cancer diagnosis, yeast artificial chromosome biopsy, cell bank /registry, genetic library, human tissue, nucleic acid probe
Project start date: 1993-02-01
Project end date: 1996-01-31
5R01CA058838-02 (1994): $191044
Small-molecule Cytotoxics Dependent On HIF1 Activity
Amato J Giaccia, Professor And Director
Stanford University
stanford, Ca 94305
Grant 5P01CA082566-080004 from National Cancer Institute IRG: NCI
Abstract: The importance of hypoxia as a critical determinant in tumor progression and response to therapy has been well-documented. It is hypothesized that the effects of hypoxia on malignant progression are based on transcriptional changes in gene expression. The development of tumor cell cytotoxins based on the critical regulators of hypoxia-induced transcription represents a new therapeutic approach. One major regulator of transcription under hypoxic conditions is the hypoxia-inducible transcription factor 1 (HIF-1). Thus, the central focus of this project will be to identify compounds that are selectively cytotoxic to tumor cells that possess elevated levels of HIF-1. The HIF-1 transcription factor is a tumor specific target and is induced by hypoxia as well as oncogenes and dysregulated growth factors. In recent years, we have developed a great deal of knowledge about the pathways and genetic determinants that influence the stabilization and activity of the oxygen-sensitive HIF-1alpha subunit of HIF-1. Recent studies indicate that mutations of proline 402 or 564 will prevent HIF-1alpha binding to VHL, an E3 ubiquitin ligase, and therefore stabilized under aerobic conditions. While pharmacologic and genetic inhibitors of HIF-1alpha stabilization and activity have been identified, no in-depth screen has been performed to identify drugs that selectively kill tumor cells that possess elevated HIF-1 levels. Thus, the major goal of this grant is to identify compounds that result in cellular growth inhibition or cytotoxicity in a HIF-1/VHL-dependent manner by performing both in silico and functional screens of the NCI drug screening libraries, as well as commercial libraries that possess wide chemical diversity. We possess the equipment and methodology to perform such screens to identify new HIF-1/VHL-dependent cytotoxins. Ultimately during this grant period, we will identify one compound that has the desired selectivity and potent anti-tumor activity in transplanted tumors to take into the clinic. This project will also investigate mechanisms of drug cytoxicity that are HIF-1 dependent. We envision that such studies will provide new insights into how to exploit HIF-1 for future drug development by identifying specific pathways that lead to cytoxicity directly through HIF-1 or in combination with HIF-1
Keywords: antineoplastic, cytotoxicity, drug discovery /isolation, drug screening /evaluation, genetic regulation, hypoxia, neoplasm /cancer, neoplasm /cancer genetics, transcription factor combination cancer therapy, drug adverse effect, drug metabolism, gene expression, neoplasm /cancer radiation therapy, nonhuman therapy evaluation, tumor suppressor gene human tissue, neoplastic cell
Sponsored Links Excellgen http://Excellgen.com
PROTEIN STABILITY UNDER HYPOXIC CONDITIONS
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 5P01CA067166-070006 from National Cancer Institute IRG: NCI
Abstract: Regulation of protein expression by hypoxia is complex and is mediated through both translational and post-translational controls. Post- translational regulation by hypoxia is an underappreciated means of regulating protein expression and is best exemplified by the alpha subunit for the HIF-1 transcription factor. Hypoxia is very unique in that it has developed a means of modulating gene expression by regulating the post- translational stabilization of a protein. Genetic and molecular analysis of HIF-1 alpha indicates that its hypoxia responsiveness is governed by two different domains located in its carboxy terminal region. One domain regulates its stabilization under hypoxic conditions (ODD) and a second domain governs its hypoxia inducible transactivation activity. Importantly, addition of the ODD to heterologous proteins can result in their enhanced degradation under aerobic conditions and increased stabilization under hypoxic conditions. Thus, one goal of the grant is to devise a scheme to regulate protein stability (and as a consequent protein activity) by changes in the oxygen environment of a tumor. However, such a strategy would have low clinical translational potential if there is not an efficient means of transducing the protein into a high percentage of tumor cells in vivo. Fortunately, a new approach to protein transduction is available that has great promise for in vivo therapeutics This approach involves the transfer of proteins into cells through their tethering to the HIV TAT protein. To date over 50 proteins ranging from 10 to 110 kd have been transferred into cells using TAT. The combination of TAT transduction of proteins under the regulation of the HIF-1 alpha ODD is a powerful means of modulating protein expression in tumor tissue and sparing normal tissue based on the well validated premise that hypoxia is not found in normal tissue. In this proposal we will test four hypotheses that will determine whether such an approach can be developed for enhanced anti-tumor therapy 1) Proteins can be made unstable under aerobic conditions by the addition of the HIF-1a oxygen degradation domain, 2) protein transduction using the HIV-TAT protein transduction domain (PDT) will be an efficient means of introducing proteins can be enhanced in tumor cells that are oxygen labile into cells in vitro, 3) tumors in vivo and 4) Stabilization of ODD transduced proteins can be enhanced in tumors cells that possess adys Ras/PI-3K signaling pathway or have lost the VHL tumor suppressor gene.
Keywords: chemical stability, hypoxia, neoplasm /cancer, oncoprotein, human immunodeficiency virus, neoplasm /cancer genetics, phosphatidylinositol 3 kinase, transcription factor, tumor suppressor gene, virus protein, genetic transduction, tissue /cell culture
MOLECULAR PHYSIOLOGY OF HYPOXIA INDUCED STRESS
Amato J Giaccia, Professor And Director
Radiation Oncologystanford University
stanford, Ca 94305
Grant 5R01CA073832-03 from National Cancer Institute IRG: RAD
Abstract: Recent experimental studies have implicated tumor micro-environment in the selection of particular genetic mutations during tumorigenesis. In response to low oxygen conditions in the growing tumor mass, certain oncogenic mutations appear to predispose cells to apoptotic cell death. This leads to selection for anti-apoptotic mutations and for a genetic switch to a pro-angiogenesis phenotype. This switch to the angiogenic phenotype is associated with a coordinated increase in expression of angiogenic-promoting cytokines such as TNFalpha, bFGF, PDGF, and VEGF. Based on data that shows that oncogenic forms of Ha-Ras can increase the expression of VEGF, the hypothesis is put forth that oncogenic transformation primes cells for VEGF expression and that tumor hypoxia would then provide the necessary signal to increase or maintain the state of angiogenic growth factor production. Experiments are proposed which will 1) Investigate whether cells which express oncogenic forms of Ras utilize PI-3 kinase in signaling the induction of pro-angiogenic cytokines and mitogens and whether this induction is regulated through HIF-1 and CACACAG/C; 2) To determine how Ras interacts with PDGF receptor and PI-3K signaling in the induction of VEGF; and 3) To investigate the relationship between the Ras and myc oncogenes and promoting cell death or survival at the unicellular and multicellular stages
Keywords: gene mutation, hypoxia, neoplasm /cancer genetics, oncogene, physiologic stressor angiogenesis, biological signal transduction, enzyme activity, gene expression, genetic regulatory element, growth factor receptor, phosphatidylinositol 3 kinase, platelet derived growth factor, programmed cell death, receptor expression, tumor necrosis factor alpha, tumor necrosis factor beta, tumor progression, vascular endothelial growth factor RNase protection assay, SCID mouse, immunocytochemistry, northern blotting, tissue /cell culture, western blotting
Project start date: 1997-12-15
Project end date: 2000-11-30
5R01CA073832-03 (2000): $210904
1R01CA073832-01A1 (1998): $210814
TUMOR HYPOXIA: MOLECULAR STUDIES & CLINICAL EXPLOITATION
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5P01CA067166-14 from National Cancer Institute
Abstract: Our program project represents a highly integrated approach to translate basic science findings on the role of hypoxia in tumor progression and resistance to therapy to pre-clinical models of cancer that we ultimately hope to take into the clinic. The overall hypothesis of this proposal is that hypoxia not only makes tumor cells resistant to therapy, but also increases their invasiveness and metastatic potential by inducing metastatic-related genes such as osteopontin (OPN) and connective tissue growth factor (CTGF). During the last four years, the investigators of this program project have worked together using yeast as well as mammalian cells to understand the genomic response of tumor cells to hypoxia and develop new targeted therapies to eliminate hypoxic cells or inhibit the secreted gene products of hypoxic cells that drive malignant progression. We have advanced understanding of gene regulation under hypoxic conditions, used the yeast deletion pool to identify genetic determinants that are critical for survival under hypoxia as well as other stress inducing conditions, and developed new diagnostics for hypoxia. In the renewal application we will further define critical effectors of the hypoxic response that will be manipulated to increase the effectiveness of new hypoxic cytotoxins as well as inhibit the activity of secreted proteins induced by hypoxia that are essential for tumor growth and expansion. Emphasis is placed on understanding and exploiting the tumor microenvironment of head & neck cancers where overcoming hypoxia is important in achieving local tumor control, and pancreatic cancers where the role of hypoxia in tumor progression has been largely uninvestigated. One way to take advantage of the decreased oxygenation status of a tumor is to administer a hypoxia-activated cytotoxin such as TPZ, which is currently being studied in Phase III clinical trials as a result from previous work in this Program Project. However, newer and more potent hypoxic cytotoxins such as PR-104, that have the additional benefit of producing a bystander effect, will be investigated in combination with cytotoxic agents such as cisplatin, inhibitors of HIF-1 which increase tumor hypoxia by shutting down mitochondrial activity and mAbs directed against CTGF and OPN that act in a cytostatic manner to inhibit tumor growth and metastases. The overall goals of this PPG are to exploit tumor hypoxia therapeutically through the inhibition of specific targets that are induced by hypoxia. Project 1 will investigate the role of HIF and CTGF in regulating tumor growth and metastases. Project 2 will investigate the efficacy of a new hypoxic cytotoxin PR-104 in combination with both cytotoxic and cytostatic agents. Project 3 will investigate mitochondrial regulation by hypoxia in yeast and mammalian cells and determine whether inhibition of HIF will increase the efficacy of hypoxic cytotoxins. Project 4 will examine the role of OPN in modulating tumor growth and metastasis. Project 5 will determine the importance of the three major signaling pathways activated by the unfolded protein response for tumor growth and adaptation to hypoxia. Few groups could be better positioned to use yeast and mammalian genetics to develop novel hypoxia based therapeutics
Project start date: 1997-04-01
Project end date: 2012-01-31
Budget start date: 1-FEB-2010
Budget end date: 31-JAN-2011
5P01CA067166-14 (2010): $1665852
Tumor Hypoxia: Molecular Studies And Clinical Exploitation
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 2P01CA067166-11A1 from National Cancer Institute IRG: ZCA1
Abstract: Our program project represents a highly integrated approach to translate basic science findings on the role of hypoxia in tumor progression and resistance to therapy to pre-clinical models of cancer that we ultimately hope to take into the clinic. The overall hypothesis of this proposal is that hypoxia not only makes tumor cells resistant to therapy, but also increases their invasiveness and metastatic potential by inducing metastatic-related genes such as osteopontin (OPN) and connective tissue growth factor (CTGF). During the last four years, the investigators of this program project have worked together using yeast as well as mammalian cells to understand the genomic response of tumor cells to hypoxia and develop new targeted therapies to eliminate hypoxic cells or inhibit the secreted gene products of hypoxic cells that drive malignant progression. We have advanced understanding of gene regulation under hypoxic conditions, used the yeast deletion pool to identify genetic determinants that are critical for survival under hypoxia as well as other stress inducing conditions, and developed new diagnostics for hypoxia. In the renewal application we will further define critical effectors of the hypoxic response that will be manipulated to increase the effectiveness of new hypoxic cytotoxins as well as inhibit the activity of secreted proteins induced by hypoxia that are essential for tumor growth and expansion. Emphasis is placed on understanding and exploiting the tumor microenvironment of head and neck cancers where overcoming hypoxia is important in achieving local tumor control, and pancreatic cancers where the role of hypoxia in tumor progression has been largely uninvestigated. One way to take advantage of the decreased oxygenation status of a tumor is to administer a hypoxia-activated cytotoxin such as TPZ, which is currently being studied in Phase III clinical trials as a result from previous work in this Program Project. However, newer and more potent hypoxic cytotoxins such as PR-104, that have the additional benefit of producing a bystander effect, will be investigated in combination with cytotoxic agents such as cisplatin, inhibitors of HIF-1 which increase tumor hypoxia by shutting down mitochondrial activity and mAbs directed against CTGF and OPN that act in a cytostatic manner to inhibit tumor growth and metastases. The overall goals of this PPG are to exploit tumor hypoxia therapeutically through the inhibition of specific targets that are induced by hypoxia. Project 1 will investigate the role of HIF and CTGF in regulating tumor growth and metastases. Project 2 will investigate the efficacy of a new hypoxic cytotoxin PR-104 in combination with both cytotoxic and cytostatic agents. Project 3 will investigate mitochondrial regulation by hypoxia in yeast and mammalian cells and determine whether inhibition of HIF will increase the efficacy of hypoxic cytotoxins. Project 4 will examine the role of OPN in modulating tumor growth and metastasis. Project 5 will determine the importance of the three major signaling pathways activated by the unfolded protein response for tumor growth and adaptation to hypoxia. Few groups could be better positioned to use yeast and mammalian genetics to develop novel hypoxia based therapeutics.
Project start date: 1997-04-01
Project end date: 2012-01-31
2P01CA067166-11A1 (2007): $1581538
Hypoxia--Molecular Studies And Clinical Exploitation
Amato J Giaccia, Professor And Director
Stanford University Stanford, Ca 94305
Grant 3P01CA067166-10S1 from National Cancer Institute IRG: NCI
Abstract: It has been recognized for decades that solid tumors can contain regions at very low oxygen concentrations (hypoxia) which do not occur in normal tissues under physiological conditions. During the last four years, we have used multiple technologies to identify and characterize the genomic response of untransformed and transformed mammalian cells to decreased oxygenation (hypoxia) as well as agents such as tirapazamine (TPZ) that become cytotoxic only under oxygen limiting conditions. During the last four years, we have used multiple technologies to identify and characterize the genomic response of untransformed and transformed mammalian cells to decreased oxygenation (hypoxia) as well as agents such as tirapazamine (TPZ) that become cytotoxic only under oxygen limiting conditions. A direct application of gene expression profiling to be used in this study is to identify hypoxia induced genes that code for a secreted products that could be detected in the serum of patients by ELISA assays (Project 4). Such an assay would be a non-invasive, rapid and simple means of assessing tumor hypoxia. One way to take advantage of the decreased oxygenation status of a tumor is to administer a hypoxia activated cytotoxin such as TPZ (Projects 1 and 2). While TPZ has demonstrated great promise in the clinic, the potential to enhance its toxicity could be achieved by increasing the formation of its damaging radical species (Project 1) and/or by inhibiting pathways that restitute the cellular damage induced by TPZ (Project 2). Expression of profiling of squamous cell carcinomas of the head and neck and cervix revealed that two family members, NIP3 (Nineteen K interacting protein) and NIP3L of the pro-apoptotic bcl-2 family are induced under hypoxic conditions (Project 3). These proteins may present a new approach to kill hypoxic cells using molecular cytotoxins that are regulated by low oxygen conditions (Projects 1 and 3). The overall goals of this PPG are to exploit tumor hypoxia therapeutically, and develop molecular markers to detect it. Thus, a common theme of hypoxia or TPZ induced changes in gene and protein expression run throughout the project. Project 1 will investigate the ability to use hypoxia to control the stabilization of proteins to kill cells directly by apoptosis or to metabolize TPZ into its radical damaging species. Project 2 will use yeast expression profiling and homozygous deletion strains to discover genes (and pathways) affecting TPZ sensitivity. Project 3 will use mammalian and yeast gene knockout and expression profiling to understand genes that affect the ability of NIP3 to kill tumor cells. Project 4 will use mammalian expression profiling of hypoxia induced genes that code for secreted proteins as surrogate markers for hypoxia. Few groups could be better positioned to use expression profiling of yeast and mammalian cells to address the mechanism of action of TPZ and pro- apoptotic genes, identify molecular hypoxia markers, and develop novel hypoxia based therapeutics.
Keywords: hypoxia, molecular oncology, neoplasm /cancer, neoplasm /cancer therapy, clinical research, human subject
Project start date: 1996-06-15
Project end date: 2007-06-30
3P01CA067166-10S1 (2006): $391601
5P01CA067166-10 (2005): $1548838
5P01CA067166-09 (2004): $1469887
Sponsored Links Excellgen http://Excellgen.com
5P01CA067166-08 (2003): $1477857
5P01CA067166-07 (2002): $1443138
2P01CA067166-06 (2001): $1439417
CANCER ETIOLOGY, PREVENTION, DETECTION AND DIAGNOSIS
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5T32CA009302-34 from National Cancer Institute
Abstract: Ever since its inception in 1978, the Stanford Cancer Biology Program aims to provide the best possible predoctoral and postdoctoral training in cancer research across the nation. One of the great strengths of the training program is its interdepartmental organization that gathers 62 faculty from 23 basic and clinical departments from the schools of Medicine and Humanities and Sciences at Stanford. The central core of our program is intensive and mentored research training. Our trainees conduct cutting-edge research in key areas of Cancer Biology such as cancer stem cells, animal models for cancer, tumor suppressor gene function, and the development of novel therapies to inhibit tumor growth and metastases. Research topics range from using Drosophila to identify genes involved in growth control, to more translational research in screening for small molecules inhibitors that selectively kill tumor cells, to clinical research that applies microarray technology to determine patients´ prognostic outcome from tumor gene-expression profiling. Predoctoral trainees build a solid foundation in the discipline of Cancer Biology through required and elective coursework, laboratory research, grant and thesis writing. Postdoctoral trainees also receive rigorous training through research, attending scientific seminars in Cancer Biology, writing fellowship applications and research manuscripts. All trainees are required to present their research at the Annual Asilomar Conference where the entire Stanford Cancer Biology Community gathers to share data and exchange ideas. Trainees are also highly encouraged to attend and present at national and international conferences. All trainees receive formal instructions on biomedical ethics. Trainees´ research progress are reviewed annually. In addition, all trainees have the opportunity to meet the invited scientific leaders to discuss about their research, career goals and opportunities. Besides the outstanding faculty mentorship, students are now exposed to the state of the art teaching facilities and research labs that foster extensive research collaborations that arise due to the rapid advancement of cancer research. Finally, with creation of the Stanford Cancer and Stem Cell Institute and the application to become a NCI designated Cancer Center, the Cancer Biology training program will serve an even more prominent role in supporting cancer education and research at Stanford
Keywords: Cancer Cause; Cancer Etiology; Detection; Diagnosis; Prevention
Project start date: 1977-09-15
Project end date: 2012-06-30
Budget start date: 1-JUL-2010
Budget end date: 30-JUN-2011
PFA/PA: PA-06-468
5T32CA009302-34 (2010): $991385
5T32CA009302-33 (2009): $956929
2T32CA009302-31 (2007): $902334
CTGF IN PANCREATIC TUMOR GROWTH
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5R01CA116685-05 from National Cancer Institute
Abstract: During the last grant period, we have obtained evidence that the expression of connective tissue growth factor (CTGF) is elevated in human pancreatic tumors, but not in normal pancreas or pancreatitis. Since pancreatic tumors are highly hypoxia and CTGF is known to be hypoxia inducible, we have focused this grant to understand the role of hypoxia and CTGF in pancreatic tumor progression. The basis for these studies to investigate the importance of CTGF in pancreatic tumor progression derive from our demonstration that targeted inhibition of CTGF with a monoclonal specific antibody results in significant growth inhibition of two different pancreatic cancer cell lines implanted as subcutaneous tumors. In this grant, we will focus on determining the mechanistic role of CTGF and its individual domains on pancreatic tumor progression under normoxic and hypoxic conditions. Our preliminary data suggests that CTGF is able to enhance the growth of pancreatic tumor cells. Induction of CTGF had no effect on cell growth on plastic, but significantly enhanced spheroid growth in soft agar. Most striking was the increase in cell adhesion induced by CTGF expression. These changes in cell adhesion that are necessary for 3-D growth lead us to test the hypothesis that one of the major roles of CTGF in malignant progression is to regulate cell-cell adhesion, and that inhibiting this activity will impact tumor growth and metastases. Thus, the aims of this proposal are to 1) determine how CTGF affects cell adhesion of pancreatic tumor cells under normoxic and hypoxic conditions using domain specific deletion mutants in cells that are manipulated to express different levels of HIF-1, 2) determine how important CTGF is for 3-D growth and invasion under normoxic and hypoxic conditions, 3) determine how inhibition of CTGF mediated adhesion affects metastatic growth, 4) determine how inhibition of cell adhesion by CTGF affects subcutaneous and orthotopic tumor growth of pancreatic tumor cells, 5) determine the role of stromal and tumor cell CTGF on tumor growth, 6) determine how effective the combination of CTGF Ab and ionizing radiation or gemcitabine are in controlling pancreatic tumor growth compared to ionizing radiation or gemcitabine alone. In summary, the proposed studies are intended to address an important mechanism by which CTGF affects tumor progression in pancreatic cancers and to determine how effective it is in combination therapy to bring it to the clinic
Keywords: 1-(2-Oxo-4-amino-1, 2-dihydropyrimidin-1-yl)-2-deoxy-2, 2-difluororibose; 2`, 2`-DFDC; 2`, 2`-difluoro-2`-deoxycytidine; 2`, 2`-difluorodeoxycytidine; 2`-deoxy-2`-difluorocytidine; 2`Deoxy-2`, 2`-Difluorocytidine; 2, 2 difluorodexoycytidine; 3-D; 3-Dimensional; Address; Adhesions; Adhesives; Affect; Agar; Antibodies; CTGF; Cancer Radiotherapy; Cancer cell line; Cell Adhesion; Cell Adhesion Inhibition; Cell-Cell Adhesion; Cells; Cellular Adhesion; Cellular Expansion; Cellular Growth; Characteristics; Clinic; Combined Modality Therapy; Data; Difluorodeoxycytidine; Effectiveness; Electromagnetic Radiation, Ionizing; Employee Strikes; Gastrointestinal Tract, Pancreas; Generalized Growth; Grant; Growth; HNSCC; Head and Neck Cancer; Head and Neck Carcinoma; Head and Neck Neoplasm (Excluding Central Nervous System); Head and Neck Neoplasms; Head and Neck Squamous Cell Carcinoma; Human; Human, General; Hypoxia; Hypoxic; IGF-binding protein-related protein-2; IGFBP-8; IGFBP-rP2; Implant; Individual; Investigators; Ionizing radiation; Lead; Malignant; Malignant - descriptor; Malignant Head and Neck Neoplasm; Malignant Pancreatic Neoplasm; Malignant Tumor of the Head and Neck; Malignant neoplasm of pancreas; Mammals, Mice; Man (Taxonomy); Man, Modern; Mediating; Metastasis; Metastasize; Metastatic Neoplasm; Metastatic Tumor; Mice; Multimodal Therapy; Multimodal Treatment; Multimodality Treatment; Murine; Mus; Neoplasm Metastasis; Oxygen Deficiency; Pancreas; Pancreas Cancer; Pancreas Neoplasms; Pancreatic; Pancreatic Cancer; Pancreatic Tumor; Pancreatitis; Pb element; Plastics; Programs (PT); Programs [Publication Type]; Protocol; Protocols documentation; Radiation; Radiation therapy; Radiation-Ionizing Total; Radiotherapeutics; Radiotherapy; Research Personnel; Researchers; Role; SCCHN; Secondary Neoplasm; Secondary Tumor; Strikes; Strikes, Employee; Stromal Neoplasm; Stromal Tumor; Testing; Tissue Growth; Tumor Cell; Tumor Cell Migration; Tumor of the Head and Neck; Tumor of the Pancreas; Tumor-Derived; base; cancer metastasis; cancer progression; cell growth; combination therapy; combined modality treatment; combined treatment; connective tissue growth factor; dFdC; dFdCyd; effective therapy; expectation; fisp12 protein; gemcitabine; head & neck cancer; head & neck tumor; head and neck tumor; heavy metal Pb; heavy metal lead; insulin-like growth factor binding protein 8; irradiation; matrigel; multimodality therapy; mutant; neoplasm progression; neoplastic cell; neoplastic progression; ontogeny; pancreatic neoplasm; programs; ray (radiation); shRNA; short hairpin RNA; small hairpin RNA; social role; subcutaneous; tumor; tumor growth; tumor progression
Project start date: 2006-09-27
Project end date: 2011-07-31
Budget start date: 1-AUG-2010
Budget end date: 31-JUL-2011
5R01CA116685-05 (2010): $177814
5R01CA116685-04 (2009): $241835
5R01CA116685-02 (2007): $241302
1R01CA116685-01A2 (2006): $260813
Sponsored Links Excellgen http://Excellgen.com
HYPOXIA, P53 AND GENETIC INSTABILITY
Amato J Giaccia, Professor And Director
Institution:
Grant 1P01CA067166-01A10004 from National Cancer Institute
Abstract: Cancer is a dynamic disease that results from an imbalance between the deregulated expression of positive growth regulators (oncogenes) and the growth inhibitory effects of negative growth regulators (tumor suppressor genes). The inactivation of negative growth regulators such as p53 and Rb has been found in many tumor types, and in general occurs late in the neoplastic process. Functionally, p53 acts as a negative growth regulator by activating either a G1/S-phase cell-cycle checkpoint or by activating an apoptotic cell death pathway in response to DNA damaging agents or growth limiting conditions. Although it is well established p53 s role in activation of a cell-cycle checkpoint in response to DNA damage is through transcriptional activation of downstream effector genes such as p21 and GADD 45, it does not seem that p53 s role as a transcription factor is needed for activation of cell death by the same agents. Recent studies by several labs have demonstrated that the introduction of dominant oncogenes such as E1A and ras into embryonic stem cells that still possess functional wild-type p53 will poise them for apoptotic cell death when subsequently exposed to DNA damaging agents or growth restrictive stresses. If these cells possess mutated p53 or are devoid of wild-type p53 activity, they exhibit a significant reduction in their ability to undergo apoptosis when exposed to the same stresses. The predisposition of oncogenically transformed cells that possess wild-type p53 to apoptotic cell death coupled with the knowledge that many p53 mutations occur at the later stages of tumor formation suggests that cells possessing wild-type p53 are somehow selected against during tumor growth. We hypothesize that hypoxia or low oxygen conditions act as a tumor specific stress to select against oncogenically transformed cells that possess wild-type p53. Hypoxia, like ionizing radiation, causes the activation of wild-type p53 protein and induces growth arrest in established cell lines. However, exposure of minimally transformed cells to low oxygen conditions in the presence of serum and glucose induces apoptotic cell death that depends on the presence of wild-type p53. The goals of this study are to investigate the genetics of p53 mediated growth arrest and apoptosis induced by low oxygen conditions. We will examine the p53 dependence of hypoxia induced growth arrest and apoptosis in p53 genetically matched mouse, rat and human cells that are minimally transformed by the introduction of dominant oncogenes. By mixing different ratios of wild-type and mutant p53 cells, we will first attempt to demonstrate in cell culture and then in multicellular spheroids that hypoxia selects against the growth of oncogenically transformed cells that possess wild-type p53, and permits the survival and/or growth of mutant p53 cells. Finally, we will correlate the oxygen status of human head and neck tumors with their p53 genotype to investigate whether there is a correlation between these two parameters in human tumors. We feel that these experiments will provide mechanistic insight into how the tumor microenvironment can play a role in selecting for the clonal expansion of a tumor cell that has lost its ability to modulate cell proliferation.
Keywords: head /neck neoplasm, hypoxia, neoplasm /cancer genetics, neoplastic growth, tumor suppressor gene, angiogenesis, gene mutation, oxygen tension, programmed cell death, thrombospondin, fluorescent in situ hybridization, genetic library, nucleic acid probe, nucleic acid sequence, polymerase chain reaction, tissue /cell culture
Amato J Giaccia
Stanford University
Project start date: 2000-07-01
Project end date: 2015-04-30
REGULATION OF TUMOR AND METASTATIC GROWTH BY HYPOXIA AND CTGF
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Keywords: 1-(2-Oxo-4-amino-1, 2-dihydropyrimidin-1-yl)-2-deoxy-2, 2-difluororibose; 2`, 2`-DFDC; 2`, 2`-difluoro-2`-deoxycytidine; 2`, 2`-difluorodeoxycytidine; 2`-deoxy-2`-difluorocytidine; 2`Deoxy-2`, 2`-Difluorocytidine; 2, 2 difluorodexoycytidine; 3-D; 3-Dimensional; Address; Adhesions; Adhesives; Affect; Agar; Agents, Cytostatic; Antibodies; CTGF; Cancer cell line; Cell Adhesion; Cell Adhesion Inhibition; Cell-Cell Adhesion; Cells; Cellular Adhesion; Cellular Expansion; Cellular Growth; Characteristics; Clinic; Clinical; Collaborations; Combined Modality Therapy; Cytostatic Drugs; Cytostatics; Cytotoxic agent; Cytotoxic drug; Cytotoxin; Data; Difluorodeoxycytidine; Effectiveness; Employee Strikes; Gastrointestinal Tract, Pancreas; Generalized Growth; Grant; Growth; Head and Neck Neoplasm (Excluding Central Nervous System); Head and Neck Neoplasms; Human; Human, General; Hypoxia; Hypoxic; IGF-binding protein-related protein-2; IGFBP-8; IGFBP-rP2; Implant; Individual; Lead; Malignant; Malignant - descriptor; Malignant Pancreatic Neoplasm; Malignant neoplasm of pancreas; Mammals, Mice; Man (Taxonomy); Man, Modern; Mediating; Metastasis; Metastasize; Metastatic Neoplasm; Metastatic Tumor; Mice; Molecular; Multimodal Therapy; Multimodal Treatment; Multimodality Treatment; Murine; Mus; Neoplasm Metastasis; Oxygen Deficiency; Pancreas; Pancreas Cancer; Pancreas Neoplasms; Pancreatic; Pancreatic Cancer; Pancreatic Tumor; Pancreatitis; Pb element; Plastics; Principal Investigator; Programs (PT); Programs [Publication Type]; Protocol; Protocols documentation; Regulation; Role; Secondary Neoplasm; Secondary Tumor; Strikes; Strikes, Employee; Stromal Neoplasm; Stromal Tumor; Testing; Tissue Growth; Tumor Cell; Tumor Cell Migration; Tumor of the Head and Neck; Tumor of the Pancreas; Tumor-Derived; base; cancer metastasis; cancer progression; cell growth; combination therapy; combined modality treatment; combined treatment; connective tissue growth factor; dFdC; dFdCyd; effective therapy; expectation; fisp12 protein; gemcitabine; head and neck tumor; heavy metal Pb; heavy metal lead; insulin-like growth factor binding protein 8; matrigel; multimodality therapy; mutant; neoplasm progression; neoplastic cell; neoplastic progression; ontogeny; pancreatic neoplasm; programs; social role; subcutaneous; tumor; tumor growth; tumor progression
Budget start date: 1-FEB-2010
Budget end date: 31-JAN-2011
5P01CA067166-14_0010 (2010): $278002
ADMINISTRATION & SCIENTIFIC SUPPORT
Amato J Giaccia, Professor & Director, Division Of Cancer
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Keywords: Advisory Committees; Cells; Clinical; Ensure; Expenditure; Goals; Human Resources; Hypoxia; Hypoxic; Investigators; Leadership; Manpower; Molecular; Monitor; Oxygen Deficiency; Programs (PT); Programs [Publication Type]; Progress Reports; Protocol; Protocols documentation; Reagent; Reporting; Reports, Progress; Research; Research Personnel; Research Resources; Researchers; Resource Allocation; Resources; Task Forces; Writing; meetings; member; personnel; programs; success; tumor
Budget start date: 1-FEB-2010
Budget end date: 31-JAN-2011
5P01CA067166-14_9003 (2010): $116833
Regulation Of Tumor And Metastatic Growth By Hypoxia And CTGF
Amato J Giaccia, Professor And Director
Stanford University
stanford, Ca 94305
Grant 5P01CA067166-120010 from National Cancer Institute IRG: ZCA1
Amato J Giaccia, Professor And Director
Stanford University
stanford, Ca 94305
Grant 5P30CA124435-020004 from National Cancer Institute IRG: NCI
Keywords: biology, radiation
Sponsored Links Excellgen http://Excellgen.com