Differential display screening for specific gene expression induced by dietary nonsteroidal estrogen.
The dietary phytoestrogen, daidzein, produced a biphasic response in cell proliferation of cultured, estrogen-responsive human breast carcinoma MCF-7 cells. Cell growth was stimulated at a daidzein concentration of 0.25 microg/ml whereas the addition of daidzein at concentrations >25 microg/ml significantly inhibited cell growth in a dose-dependent fashion, resulting in an IC50 value of 50 microg/ml. Upon exposure to 50 microg/ml of daidzein, cell morphology was severely altered, cell volume decreased, and condensation of the chromosomes was clearly noticeable. To identify genes whose expression were inhibited by daidzein, a differential display reverse transcriptase polymerase chain reaction assay (DD-RT-PCR) was performed and the cDNA fragments of several daidzein-regulated genes were visualized. The sequence of one of the cloned cDNA fragments that showed differential mRNA expression level in response to daidzein at a concentration of 50 microg/ml had a high homology with a cDNA expressed in fetal human brain, EST 06411.
Hsu
J T
JT
Department of Animal Sciences, National Taiwan University, Taipei, Republic of China.
Jean
T C
TC
Chan
M A
MA
Ying
C
C
D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D018076:DNA, Complementary; D004958:Estradiol / Q000737:chemistry / Q000494:pharmacology*; D004968:Estrogens, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007529:Isoflavones / Q000737:chemistry / Q000494:pharmacology*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004968:Estrogens, Non-Steroidal; D007529:Isoflavones; D004958:Estradiol; C004742:daidzein