TY - JOUR
T1 - The proximal promoter region of the human vascular endothelial growth factor gene has a G-quadruplex structure that can be targeted by G-quadruplex-interactive agents
AU - Sun, Daekyu
AU - Liu, Wei Jun
AU - Guo, Kexiao
AU - Rusche, Jadrian J.
AU - Ebbinghaus, Scot
AU - Gokhale, Vijay
AU - Hurley, Laurence H.
PY - 2008/4/1
Y1 - 2008/4/1
N2 - Previous studies on the functional analysis of the human vascular endothelial growth factor (VEGF) promoter using the full-length VEGF promoter reporter revealed that the proximal 36-bp region (-85 to -50 relative to transcription initiation site) is essential for basal or inducible VEGF promoter activity in several human cancer cells. This region consists of a polypurine (guanine) tract that contains four runs of at least three contiguous guanines separated by one or more bases, thus conforming to a general motif capable of forming an intramolecular G-quadruplex. Here, we show that the G-rich strand in this region is able to form an intramolecular propeller-type parallel-stranded G-quadruplex structure in vitro by using the electrophoretic mobility shift assay, dimethyl sulfate footprinting technique, the DNA polymerase stop assay, circular dichroism spectroscopy, and computer-aided molecular modeling. Two well-known G-quadruplex-interactive agents, TMPyP4and Se2SAP, stabilize G-quadruplex structures formed by this sequence in the presence of a potassium ion, although Se2SAP is at least 10-fold more effective in binding to the G-quadruplex than TMPyP4. Between these two agents, Se2SAP better suppresses VEGF transcription in different cancer cell lines, including HEC1A and MDA-MB-231. Collectively, our results provide evidence that specific G-quadruplex structures can be formed in the VEGF promoter region, and that the transcription of this gene can be controlled by ligand-mediated G-quadruplex stabilization. Our results also provide further support for the idea that G-quadruplex structures may play structural roles in vivo and therefore might provide insight into novel methodologies for rational drug design.
AB - Previous studies on the functional analysis of the human vascular endothelial growth factor (VEGF) promoter using the full-length VEGF promoter reporter revealed that the proximal 36-bp region (-85 to -50 relative to transcription initiation site) is essential for basal or inducible VEGF promoter activity in several human cancer cells. This region consists of a polypurine (guanine) tract that contains four runs of at least three contiguous guanines separated by one or more bases, thus conforming to a general motif capable of forming an intramolecular G-quadruplex. Here, we show that the G-rich strand in this region is able to form an intramolecular propeller-type parallel-stranded G-quadruplex structure in vitro by using the electrophoretic mobility shift assay, dimethyl sulfate footprinting technique, the DNA polymerase stop assay, circular dichroism spectroscopy, and computer-aided molecular modeling. Two well-known G-quadruplex-interactive agents, TMPyP4and Se2SAP, stabilize G-quadruplex structures formed by this sequence in the presence of a potassium ion, although Se2SAP is at least 10-fold more effective in binding to the G-quadruplex than TMPyP4. Between these two agents, Se2SAP better suppresses VEGF transcription in different cancer cell lines, including HEC1A and MDA-MB-231. Collectively, our results provide evidence that specific G-quadruplex structures can be formed in the VEGF promoter region, and that the transcription of this gene can be controlled by ligand-mediated G-quadruplex stabilization. Our results also provide further support for the idea that G-quadruplex structures may play structural roles in vivo and therefore might provide insight into novel methodologies for rational drug design.
UR - http://www.scopus.com/inward/record.url?scp=42249101229&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=42249101229&partnerID=8YFLogxK
U2 - 10.1158/1535-7163.MCT-07-2119
DO - 10.1158/1535-7163.MCT-07-2119
M3 - Article
C2 - 18413801
AN - SCOPUS:42249101229
SN - 1535-7163
VL - 7
SP - 880
EP - 889
JO - Molecular Cancer Therapeutics
JF - Molecular Cancer Therapeutics
IS - 4
ER -