title: The proliferative response of NB69 human neuroblastoma cells to a 50 Hz magnetic field is mediated by ERK1/2 signaling.
abstract: A number of studies have reported that extremely low frequency magnetic fields (ELF-MF) can modulate proliferative processes in vitro; however, the transduction mechanisms implicated in such phenomena remain to be identified. The present study was aimed to determine whether a 50 Hz, 100 μT MF can induce cell proliferation in the human neuroblastoma line NB69, and whether the signaling pathway MAPK-ERK1/2 (Mitogen-Activated Protein Kinase - Extracellular-Signal-Regulated Kinase 1 and 2) is involved in that proliferative response. The cultures were exposed intermittently or continuously to the MF for a 63-hour duration. The continuous treatment did not induce significant changes in cell proliferation. In contrast, intermittent exposure caused statistically significant increase in the percent of cells in phase S of the cell cycle, followed by a significant increase in cell number. The intermittent treatment also induced an early, transient and repetitive activation of ERK1/2 that could be involved in the proliferative effects. In fact, both the proliferative response and the repeated activation of ERK1/2 were blocked by PD98059, the specific inhibitor of MEK (ERK kinases 1 and 2). Taken together, the described results indicate that a 50 Hz, 100 μT MF can stimulate proliferation in NB69 cells by triggering MAPK-ERK1/ 2 signaling at each of the "On" periods of an intermittent exposure.
authors.affiliation: Servicio de Investigación-BEM, Hospital Ramón y Cajal - IRYCIS, Madrid, Spain. m.antonia.martinez@hrc.es
authors.forename: María Antonia
authors.initials: MA
authors.lastname: Martínez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Úbeda
authors.forename: María Antonia
authors.initials: MA
authors.lastname: Cid
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Trillo
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D020935:MAP Kinase Signaling System; D008280:Magnetics; D009447:Neuroblastoma / Q000201:enzymology / Q000473:pathology*; D010766:Phosphorylation
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein