Platelet-derived growth factor increases the activity of the promoter of the insulin-like growth factor-1 (IGF-1) receptor gene.
Stimulation by platelet-derived growth factor (PDGF) is known to increase the number of IGF-I binding sites in cells in culture. We show here that PDGF also increases the levels of IGF-1 receptor mRNA. Using cell lines stably transfected with an expression plasmid in which the reporter luciferase gene is under the control of the rat IGF-1 receptor gene promoter, we find that PDGF increases the activity of this promoter. A short IGF-1 receptor gene promoter, comprising about 100 base pairs of the sequence immediately upstream of the initiation of transcription site, is sufficient for a response to the stimulatory action of PDGF. These results suggest that an increase in RNA levels and in promoter activity may play an important role in the increase in IGF-1 receptor levels that occurs after stimulation by PDGF.
Rubini
M
M
Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Werner
H
H
Gandini
E
E
Roberts
C T
CT
LeRoith
D
D
Baserga
R
R
D016475:3T3 Cells / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics*; D014162:Transfection
D000952:Antigens, Polyomavirus Transforming; D018076:DNA, Complementary; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D008156:Luciferases; D017526:Receptor, IGF Type 1