title: Static magnetic fields modulate X-ray-induced DNA damage in human glioblastoma primary cells.
abstract: Although static magnetic fields (SMFs) are used extensively in the occupational and medical fields, few comprehensive studies have investigated their possible genotoxic effect and the findings are controversial. With the advent of magnetic resonance imaging-guided radiation therapy, the potential effects of SMFs on ionizing radiation (IR) have become increasingly important. In this study we focused on the genotoxic effect of 80 mT SMFs, both alone and in combination with (i.e. preceding or following) X-ray (XR) irradiation, on primary glioblastoma cells in culture. The cells were exposed to: (i) SMFs alone; (ii) XRs alone; (iii) XR, with SMFs applied during recovery; (iv) SMFs both before and after XR irradiation. XR-induced DNA damage was analyzed by Single Cell Gel Electrophoresis assay (comet assay) using statistical tools designed to assess the tail DNA (TD) and tail length (TL) as indicators of DNA fragmentation. Mitochondrial membrane potential, known to be affected by IR, was assessed using the JC-1 mitochondrial probe. Our results showed that exposure of cells to 5 Gy of XR irradiation alone led to extensive DNA damage, which was significantly reduced by post-irradiation exposure to SMFs. The XR-induced loss of mitochondrial membrane potential was to a large extent averted by exposure to SMFs. These data suggest that SMFs modulate DNA damage and/or damage repair, possibly through a mechanism that affects mitochondria.
authors.affiliation: Radiation Development and Application, UTAPRAD-DIM, ENEA, Via Enrico Fermi 45, Frascati, Rome 00044, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Teodori
authors.forename: Anna
authors.initials: A
authors.lastname: Giovanetti
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Albertini
authors.forename: Marco
authors.initials: M
authors.lastname: Rocchi
authors.forename: Barbara
authors.initials: B
authors.lastname: Perniconi
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Valente
authors.forename: Dario
authors.initials: D
authors.lastname: Coletti
mesh_terms: D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D004249:DNA Damage / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005909:Glioblastoma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D060526:Magnetic Fields; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000235:genetics* / Q000528:radiation effects; D014407:Tumor Cells, Cultured; D014965:X-Rays / Q000009:adverse effects*
chemical_list: D004273:DNA, Neoplasm
keywords: DNA fragmentation; comet assay; glioblastoma; ionizing radiation; mitochondrial membrane potential; static magnetic field