[Establishment of drug screening model based on transcriptional regulation of estrogen responsive element].
OBJECTIVE
AIM To establish a drug screening model based on transcriptional regulation of estrogen responsive element (ERE) and use it to screen compounds for discovering new ligands of estrogen receptor (ER) subtypes.


METHODS
A recombinant reporter vector pERE-TAL-SEAP was constructed by inserting a synthetic sequence composed of five tandem copies of EREs upstream of promoter of the reporter vector pTAL-SEAP. The pERE-TAL-SEAP and the internal control plasmid pCMV were transiently co-transfected into Hela cells expressing ER subtype or ER subtype, and the effects of pure ER agonists 17estradiol, phytoestrogen genistein and pure ER antagonist ICI182, 780 on reporter gene SEAP expression were observed.


RESULTS
In the Hela cells expressing ER alpha or ER beta subtype, the expression of SEAP gene were induced in a dose dependent manner by 17-estrodiol with a maximal effect at approximately 10 nmol.L-1 and with EC50 of (80.58 +/- 8.51) pmol.L-1 and (103.90 +/- 5.29) pmol.L-1, respectively, so done by phytoestrogen genistein with a maximal effect at 1 mumol.L-1 and with EC50 of (10.86 +/- 0.75) nmol.L-1 and (39.38 +/- 2.26) nmol.L-1, respectively. The maximal level induced by estrodiol and genistein were about 7-14 fold higher than that of vehicle. The pure antiestrogen ICI182, 780 at concentration of 1 mumol.L-1 completely blocked the inductions of 17-estrodiol and genistein.


CONCLUSIONS
The cellular drug screening model can be established by transfecting reporter vector pERE-TAL-SEAP in Hela cell lines expressing ER alpha or ER beta. The cell lines can be used to screen compounds with estrogenicity by testing SEAP activity in the culture media of cells growing in microtitier wells. The system should provide an efficient model for screening and analyzing the activity of large numbers of ligands of ER.
Wang
Ling-qiao
LQ
Beijing University of Chinese Medicine and Pharmacology, Beijing 100029, China.
Lu
Qiu-jun
QJ
Niu
Jian-zhao
JZ
Wang
Jing-feng
JF
Qu
Yan-yan
YY
Wen
Li-qing
LQ
Zheng
Long-tai
LT
Chen
Yuan-yuan
YY
Zhang
Ming
M
D004353:Drug Evaluation, Preclinical / Q000379:methods; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D019833:Genistein / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D011401:Promoter Regions, Genetic; D011960:Receptors, Estrogen / Q000235:genetics*; D014162:Transfection
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D008024:Ligands; D011960:Receptors, Estrogen; D004958:Estradiol; D019833:Genistein