Rubini M, Werner H, Gandini E, Roberts C T, LeRoith D, Baserga R
Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Exp Cell Res. 1994 Apr;211(2):374-9. doi: 10.1006/excr.1994.1101.
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.
已知血小板衍生生长因子（PDGF）刺激可增加培养细胞中胰岛素样生长因子-I（IGF-I）结合位点的数量。我们在此表明，PDGF还可增加IGF-1受体mRNA的水平。使用稳定转染了表达质粒的细胞系，其中报告荧光素酶基因受大鼠IGF-1受体基因启动子的控制，我们发现PDGF可增加该启动子的活性。一个短的IGF-1受体基因启动子，包含转录起始位点上游约100个碱基对的序列，足以对PDGF的刺激作用产生反应。这些结果表明，RNA水平和启动子活性的增加可能在PDGF刺激后IGF-1受体水平的增加中起重要作用。
