Estrogen receptor expression and growth-promoting function in human choriocarcinoma cells.
Tamoxifen (1.0 microM) was found to inhibit the expression of a thymidine kinase (TK) promoter-reporter gene, lacking an estrogen response element (ERE), in transiently transfected BeWo cells, suggesting that inhibition of TK promoter activity was linked to secondary estrogen-dependent effects on BeWo cell function. Estradiol (0.05-0.45 microM) stimulated BeWo cell proliferation and increased the percentage of S-phase cells. Tamoxifen (1.35-4.05 microM) inhibited BeWo cell growth and antagonized the stimulatory actions of 0.15 microM estradiol. Reverse transcription-polymerase chain reaction and Western analyses confirmed the presence of estrogen receptor (ER) transcripts and the 67-kD ER in BeWo cells. The BeWo cell ER binds to an ERE consensus sequence and the ER-ERE complex is supershifted by antibodies directed against the ER. We conclude that BeWo cells express a functional ER that is important for the control of BeWo cell proliferation, suggesting a potential role for estrogens in mediating placental trophoblast growth and development.
Jiang
S W
SW
Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Lloyd
R V
RV
Jin
L
L
Eberhardt
N L
NL
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019556:COS Cells; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002822:Choriocarcinoma / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D011960:Receptors, Estrogen / Q000096:biosynthesis / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000235:genetics; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000378:metabolism* / Q000473:pathology
D017931:DNA Primers; D009838:Oligodeoxyribonucleotides; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D013629:Tamoxifen; D004958:Estradiol; D008156:Luciferases; D013937:Thymidine Kinase