The vascular endothelial growth factor (VEGF) and hypoxia induciblefactor (HIF)-la play a pivotal role in tumor angiogenesis. The overall objective of this proposal is to explore a new therapeutic strategy aimed at preventing tumor angiogenesis by repressing the transcription of VEGF and HIF-lcc genes through targeting G-quadruplex structures formed in the promoter region of these genes with small molecules.
The specific aims of this proposal are as follows: (1) To investigate whether G-quadruplex structures are formed in vivo in the promoter regions of VEGF and HIF-la genes in tumor cells and can be targeted with small molecules. (2) To determine the role of G-quadruplex structures in VEGF and HIF-la promoter regions in the regulation of these genes and how G-quadruplex interactive compounds modulate the regulation of these genes. (3) To explore the potential application of G-quadruplex- interactive agents as a new class of anti-angiogenic agents, which can repress the transcriptional activity of the VEGF and HIF-la genes. (4) To discover new classes of G-quadruplex compounds or new lead compounds based on known classes of G-quadruplex-interactive agents that specifically inhibit the transcriptional activation mediated by the promoter activity of VEGF and FHF-la genes. The formation of G-quadruplex structures in the promoter region of the VEGF and HIF-la genes will be studied by using in vivo chemical and enzymatic probing techniques. We will use mutation analysis and promoter reporter assays to determine the role of G-quadruplex structures formed in the promoter region of these genes. Utilizing multiple RT-PCR, microarray analysis, ChIP assay, bioluminescent imaging technique, and angiogenesis assays, we will evaluate in vitro and in vivo target selectivity and antiangiogenic activity of G-quadruplex-interactive agents. Lastly, cell free biochemical assays and cell based high-throughput screening system will be utilized to identify other lead compounds that selectively downregulate either VEGF or HIF-la expression in a cell culture system. These studies lead directly to the evaluation of the anti-angiogenic and antitumor effects of G- quadruplex-interactive agents in a preclinical model of human kidney cancer, a tumor type characterized by the abnormal overexpression of HIF-la and VEGF due to the frequent loss of the von Hippel Lindau (VHL) tumor suppressor gene.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
3R01CA109069-05S2
Application #
8034667
Study Section
Drug Discovery and Molecular Pharmacology Study Section (DMP)
Program Officer
Ogunbiyi, Peter
Project Start
2006-04-01
Project End
2012-02-28
Budget Start
2010-03-01
Budget End
2012-02-28
Support Year
5
Fiscal Year
2010
Total Cost
$54,629
Indirect Cost
Name
University of Arizona
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
806345617
City
Tucson
State
AZ
Country
United States
Zip Code
85721
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Sun, Daekyu; Guo, Kexiao; Shin, Yoon-Joo (2011) Evidence of the formation of G-quadruplex structures in the promoter region of the human vascular endothelial growth factor gene. Nucleic Acids Res 39:1256-65
Sun, Daekyu (2010) In vitro footprinting of promoter regions within supercoiled plasmid DNA. Methods Mol Biol 613:223-33
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