title: Effect of low frequency (LF) electric fields on gene expression of a bone human cell line.
abstract: We evaluated the effects, on cultured human SaOS-2 cells, of exposures to the low frequency (LF) electric signal (60 kHz sinusoidal wave, 24.5 V peak-to-peak voltage, amplitude modulated by a 12.5 Hz square wave, 50% duty cycle) from an apparatus of current clinical use in bone diseases requiring regenerating processes. Cells in flasks were exposed to a capacitively coupled electric field giving electric current density in the sample of 4 µA/cm(2). The whole expressed cellular mRNAs were systematically analyzed by "DNA microchips" technology to identify all individual species quantitatively affected by field exposure. Comparisons were made between RNA samples from exposed and control sham-exposed cells. Results indicated that immediately and 4 h after exposure there were almost no differentially modulated mRNA species. However, samples obtained at 24 h after exposure showed a small number of limitedly differential signals (7 down-regulated and 3 up-regulated with a cut-off value of ±1.5; 38 and 11, respectively, with a cut-off value of ±1.3), which included mostly mRNA encoding transcription factors and DNA binding proteins. Nevertheless, in identical experimental conditions, we previously demonstrated enzymatic changes of alkaline phosphatase occurring immediately after exposure and declining in a few hours. Therefore, since enzymatic changes occur before those observed at gene regulation level, it is conceivable that only earlier effects are directly due the treatment and then these effects are later able to affect gene expression only indirectly.
authors: Department of Pharmacy and.
authors: Mariella
authors: M
authors: Caputo
authors: Hylde
authors: H
authors: Zirpoli
authors: Maria Caterina
authors: MC
authors: De Rosa
authors: Tania
authors: T
authors: Rescigno
authors: Francesco
authors: F
authors: Chiadini
authors: Antonio
authors: A
authors: Scaglione
authors: Claudia
authors: C
authors: Stellato
authors: Giorgio
authors: G
authors: Giurato
authors: Alessandro
authors: A
authors: Weisz
authors: Mario Felice
authors: MF
authors: Tecce
authors: Bruno
authors: B
authors: Bisceglia
mesh_terms: D001842:Bone and Bones / Q000166:cytology* / Q000528:radiation effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004574:Electromagnetic Fields; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D012333:RNA, Messenger
keywords: Bone regeneration; DNA microarray; LF capacitively coupled electric fields; SaOS-2 cell line