title: Effects of the pesticides prochloraz and methiocarb on human estrogen receptor alpha and beta mRNA levels analyzed by on-line RT-PCR.
abstract: Exposure to endocrine disrupters such as dioxins, PCBs and certain pesticides are suspected to affect human reproductive health. We have analyzed the effect of the currently used pesticides prochloraz and methiocarb on the estrogen receptor (ER)alpha and beta mRNA levels in parallel with the natural ligand, 17beta-estradiol (E2). Using the highly sensitive on-line RT-PCR technique we were able to quantify the ERalpha and ERbeta mRNA levels in the human breast cancer cell line, MCF7-BUS. Upon exposure with E2 or prochloraz a down regulation of ERalpha and ERbeta mRNAs was observed after 48 h of treatment. Co-treatment with the ER antagonist ICI 182,780 abolished these mRNA down regulations. Western blot analyses elicited a decreased ER protein level after 3 h of exposure with prochloraz but after 24 h the ERalpha protein level had recovered to basal level. Methiocarb exposure had no effect on the ERalpha mRNA level, whereas an increase in the ERbeta mRNA level was observed after 3 h of exposure. Our study demonstrates that like E2, prochloraz had the potential to down regulate the expression of ERalpha and ERbeta mRNAs as well as the ERalpha protein level in MCF7-BUS cells.
authors.affiliation: Department of Environmental and Occupational Medicine, University of Aarhus, Vennelyst Boulevard 6, DK-8000C Aarhus, Denmark. mvh@mil.au.dk
authors.forename: M V
authors.initials: MV
authors.lastname: Hofmeister
authors.forename: E C
authors.initials: EC
authors.lastname: Bonefeld-Jørgensen
mesh_terms: D001331:Automation; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000473:pathology; D015536:Down-Regulation; D047628:Estrogen Receptor alpha / Q000096:biosynthesis* / Q000187:drug effects; D047629:Estrogen Receptor beta / Q000096:biosynthesis* / Q000187:drug effects; D005659:Fungicides, Industrial / Q000633:toxicity*; D006801:Humans; D007093:Imidazoles / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D008714:Methiocarb / Q000633:toxicity*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005659:Fungicides, Industrial; D007093:Imidazoles; D007306:Insecticides; D012333:RNA, Messenger; C045362:prochloraz; D008714:Methiocarb