title: Gene expression in human breast epithelial cells exposed to 60 Hz magnetic fields.
abstract: Epidemiology suggests a possible relationship between exposure to power frequency magnetic fields (EMF) and breast cancer. One mechanism through which EMF could stimulate breast cancer induction is via altered expression of oncogenes and/or tumor suppressor genes that regulate normal and neoplastic growth. To evaluate the hypothesis that EMF action in the breast is mediated by alterations in gene expression, transcript levels of c-myc and a battery of other cancer-associated genes were quantitated in human breast epithelial cells exposed to pure, linearly polarized 60 Hz EMF with low harmonic distortion. HBL-100 cells and normal (non-transformed) human mammary epithelial cells were exposed to EMF flux densities of 0.1, 1.0 and 10.0 Gauss (G) for periods ranging from 20 min to 24 h; concurrent sham controls were exposed to ambient fields (<0.001 G) only. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure. These results suggest that EMF is unlikely to influence breast cancer induction through a mechanism involving altered expression of these genes.
authors.affiliation: Experimental Toxicology and Carcinogenesis Division, Microbiology and Immunology Division and Electronics and Electromagnetics Section, IIT Research Institute, Chicago, IL 60616, USA.
authors.forename: L I
authors.initials: LI
authors.lastname: Loberg
authors.forename: J R
authors.initials: JR
authors.lastname: Gauger
authors.forename: J L
authors.initials: JL
authors.lastname: Buthod
authors.forename: W R
authors.initials: WR
authors.lastname: Engdahl
authors.forename: D L
authors.initials: DL
authors.lastname: McCormick
mesh_terms: D001940:Breast / Q000528:radiation effects*; D002273:Carcinogens; D002460:Cell Line; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004847:Epithelial Cells / Q000528:radiation effects; D005260:Female; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D016259:Genes, myc / Q000528:radiation effects*; D006801:Humans; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D011829:Radiation Dosage; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate; D013997:Time Factors
chemical_list: D002273:Carcinogens; D016271:Proto-Oncogene Proteins c-myc; D018719:Erb-b2 Receptor Tyrosine Kinases; D013755:Tetradecanoylphorbol Acetate