[Effects of p-nonylphenol on expression of ER protein and ER alpha mRNA of MCF-7 cells].
OBJECTIVE
To investigate the estrogenicity of p-nonylphenol (p-NP) through observation of its effects on expression of estrogen receptor (ER) and ER alpha mRNA of MCF-7 human breast cancer cells.


METHODS
MCF-7 cells were maintained in RPMI-1640 medium containing 10% bovine serum. Before addition of p-NP, the cells were washed by phenol red-free DMEM medium and then maintained in phenol red-free DMEM medium containing 3% charcoal/dextran treated fetal bovine serum for 3 days. The effects of five concentrations of p-NP on expression of ER protein and ER alpha mRNA were assayed using semi-quantitative immunohistochemical method and quantitative RT-PCR respectively, vehicle control and positive control were used.


RESULTS
Expression of ER protein in MCF-7 cells was down regulated by 1 x 10(-5) mol/L p-NP when cells were treated for 24 h. Expression of ER alpha mRNA in MCF-7 cells was down regulated by 1 x 10(-6) mol/L-1 x 10(-5) mol/L p-NP when cells were treated for 2 h and 24 h. Expression of both ER protein and ER alpha mRNA in MCF-7 cells showed a tendency of decline when the time of exposure to different concentrations of p-NP was elongated.


CONCLUSIONS
p-NP could down regulate the expression of both ER protein and ER alpha mRNA in MCF-7 cells, which mimicked the effects of estradiol and thus revealed the estrogenicity of p-NP.
Shen
Huiyun
H
Department of Toxicology, West China School of Public Health, Sichuan University, Chengdu 610041, China.
Xu
Peiyu
P
Yu
Wensan
W
Liu
Yuqing
Y
Wu
Desheng
D
D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D010636:Phenols / Q000633:toxicity*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D010636:Phenols; D012333:RNA, Messenger; D011960:Receptors, Estrogen; C041594:4-nonylphenol