[Effect of insulin, cAMP, and dexamethasone on phosphoenolpyruvate carboxykinase gene promoter in vitro].
OBJECTIVE
To study the effect of insulin, cyclic adenosine monophosphate (cAMP), and dexamethasone (DEX) on 550 bp (-600 -/+ 69) fragment of phosphoenolpyruvate carboxykinase (PEPCK) gene promoter by reporter gene.


METHODS
The recombinant pGL2-PEPCK-Luc and the control plasmid pSV-beta-Galactosidase were co-transfected to rat hepatoma cell line (CBRH7919) by lipofectin. By measuring luciferase activity, we evaluated in vitro regulation of PEPCK gene promoter on reporter gene transcription.


RESULTS
cAMP and DEX stimulated PEPCK promoter obviously; meanwhile, they also had accumulative effects. At different physiological concentrations, insulin had a suppressive effect on PEPCK promoter, which was dose-independent.


CONCLUSIONS
There is a perfect feedback mechanism for PEPCK promoter in hepatoma cell. 550 bp (-600 -/+ 69) fragment of PEPCK may be a candidate gene in the gene therapy of diabetes.
Feng
Kai
K
Department of Endocrinology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. fengkai@medmail.com.cn
Wang
Heng
H
Sun
Qi
Q
Xiao
Xin-Hua
XH
D000818:Animals; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008114:Liver Neoplasms, Experimental / Q000473:pathology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D007328:Insulin; D011994:Recombinant Proteins; D003907:Dexamethasone; D000242:Cyclic AMP; D008156:Luciferases; D010729:Phosphoenolpyruvate Carboxykinase (GTP)