title: Induction of tamoxifen resistance in breast cancer cells by ELF electromagnetic fields.
abstract: The incidence of breast cancer in western societies has been rising ever since the Second World War. Besides the exposure to a multitude of new chemical compounds, electromagnetic field exposure has been linked to breast cancer through a radiation-mediated anti-melatonin pathway. We investigated, whether low-frequency electromagnetic field exposure interferes with the anti-estrogenic activity of tamoxifen. Two different clones of the breast cancer cell line MCF-7 were exposed to highly homogeneous 50Hz electromagnetic fields and IC(50) values were calculated from dose-response curves of tamoxifen at various field intensities. An intensity-dependent shift of tamoxifen dose-response curves to higher concentrations with a maximal response at 1.2muT was observed. Hypothetically, electromagnetic field exposure could contribute to tamoxifen resistance observed in breast cancer after long-term treatment.
authors.affiliation: Department of Obstetrics and Gynecology, University of Göttingen, Germany. rainer.girgert@med.uni-goettingen.de
authors.forename: Rainer
authors.initials: R
authors.lastname: Girgert
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schimming
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Körner
authors.forename: Carsten
authors.initials: C
authors.lastname: Gründker
authors.forename: Volker
authors.initials: V
authors.lastname: Hanf
mesh_terms: D001943:Breast Neoplasms; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D019008:Drug Resistance, Neoplasm / Q000528:radiation effects*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D005260:Female; D006801:Humans; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D004965:Estrogen Antagonists; D013629:Tamoxifen