The Effect of Cytokines on Expression of Growth Hormone Gene
in Rat Pituitary GH3 Cells

GONG Feng-Ying, DENG Jie-Ying*, SHI Yi-Fan, ZHANG Dian-Xi

( Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy Medical Sciences & Peking Union Medical College, Beijing 100730, China )

Abstract To study the effect of interleukin-11 (IL-11), ciliary neurotropic factor (CNTF) and transforming growth factor-b (TGF-b) on the hGH gene promoter activity in rat pituitary GH3 cells and the interaction with pituitary-specific transcription factor Pit-1, firstly the stable transformed GH3 cell line which contained hGH gene promoter -484 to 30 bp and luciferase reporter gene was established, then the concentration of GH in the medium and lysate of GH3 cells and luciferase activities in GH3 cells were measured, after treating these cells with the above cytokines, the effects of cytokines on secretion and synthesis of GH, and the promoter activity of the hGH gene were observed. The results of our experiments showed that IL-11 (20 nmol/L), CNTF (10 nmol/L) and TGF-b (5 nmol/L) regulated secretion and synthesis of GH, and the luciferase expression in stable-transformed GH3 cells. IL-11 and CNTF had a stimulatory effect, whereas TGF-b had an inhibitory one. Neither overexpression of Pit-1 nor inhibition of Pit-1 expression could affect the regulatory role of these cytokines. In conclusion, IL-11, CNTF and TGF-b regulated the GH production in pituitary GH3 cell line by regulating the hGH gene promoter activity, while Pit-1 might not be involved in the roles.

Key words cytokine; hGH gene promoter; GH3 cells; Pit-1 protein

Corresponding author: Tel, 86-10-65295075; e-mail, [email protected]