title: Effects of 2450 MHz electromagnetic fields with a wide range of SARs on methylcholanthrene-induced transformation in C3H10T1/2 cells.
abstract: This study examined whether 2450 MHz continuous wave high frequency electromagnetic fields (HFEMF) could induce cancer-like changes in mouse C3H10T1/2 cells, and whether HFEMF could initiate malignant or synergistic transformation. Transformed foci, Type II and Type III, were independently counted as the experiment endpoint. The cells were exposed to HFEMF alone at a wide range of specific absorption rates (SARs) of 5 to 200 W/kg for 2 h and/or were treated with a known initiating chemical, methylcholanthrene (MC) (2.5 microg/ml). No significant differences were observed in the malignant transformation (Type II + Type III) frequency between the controls and HFEMF with or without 12-O-tetradecanoylphorbol-13-acetate (TPA) (0.5 ng/ml), a tumor promoter that could enhance transformation frequency initiated by MC in multistage carcinogenesis. However, the transformation frequency for HFEMF at SAR of more than 100 W/kg with MC or MC plus TPA was increased compared with MC alone or MC plus TPA. On the other hand, the corresponding heat groups (heat alone, heat + MC, and heat + MC + TPA) did not increase transformation compared with each control level in C3H10T1/2 cells. This result suggests that 2450 MHz HFEMF could not contribute to the initiation stage of tumor formation, but it may contribute to the promotion stage at the extremely high SAR (100 W/kg).
authors.affiliation: Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki 036-8564, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Tomonori
authors.initials: T
authors.lastname: Sakurai
authors.forename: Shin
authors.initials: S
authors.lastname: Koyama
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Komatubara
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Masao
authors.initials: M
authors.lastname: Taki
authors.forename: Junji
authors.initials: J
authors.lastname: Miyakoshi
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects*; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D008748:Methylcholanthrene / Q000008:administration & dosage*; D051379:Mice; D008809:Mice, Inbred C3H; D008872:Microwaves; D009381:Neoplasms, Radiation-Induced / Q000473:pathology; D011829:Radiation Dosage; D012062:Relative Biological Effectiveness
chemical_list: D008748:Methylcholanthrene