[The Effect of Cytokines on Expression of Growth Hormone Gene in Rat Pituitary GH(3) Cells].

To study the effect of interleukin-11(IL-11), ciliary neurotropic factor (CNTF) and transforming growth factor-beta (TGF-beta) on the hGH gene promoter activity in rat pituitary GH(3) cells and the interaction with pituitary-specific transcription factor Pit-1, firstly the stable transformed GH(3) cell line which contained hGH gene promoter 484-30 bp and luciferase reporter gene was established, then the concentration of GH in the medium and lysate of GH(3) cells and luciferase activities in GH(3) 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-beta(5 nmol/L) regulated secretion and synthesis of GH, and the luciferase expression in stable-transformed GH(3) cells. IL-11 and CNTF had a stimulatory effect, whereas TGF-beta 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-beta regulated the GH production in pituitary GH(3) cell line by regulating the hGH gene promoter activity, while Pit-1 might not be involved in the roles.