Influence of non-thermal 900 MHZ mobile phone radiation on morphology, metabolic activity and differential gene expression in a breast adenocarcinoma and normal breast epithelial cell line

Abstract

Mobile phones and other hand-held type transceivers are widely used in the world and their utilization currently exceeds landline communication in Africa. This has raised concerns about the long-term health effects of their ongoing ever-increasing usage. In the present study, the in vitro effects of 1 hour exposure to 2W/kg non-thermal 900 MHz mobile phone radiation were assessed on morphology, metabolic activity and gene expression in breast adenocarcinoma (MCF-7) and normal breast epithelial (MCF-12A) cells. Light microscopy revealed no qualitative and quantitative differences in morphology of RF-exposed versus control MCF-12A and MCF-7 cells. Correspondingly, no significant differences in nuclear morphology were observed via fluorescence microscopy using propidium iodide and Hoechst 33342 staining. Statistically insignificant changes were observed in mitochondrial dehydrogenase enzyme activity in RF-exposed MCF-7 and MCF-12A cells respectively. Microarray analyses and bioinformatics analyses revealed 31 differentially expressed genes in the MCF-7 and 19 genes in the MCF-12A cell line. Genes involved in DNA repair in the MCF-7 cells include excision repair cross-complementing rodent repair deficiency complementation group 4 (ERCC4), DNA cross-link repair 1C (DCLRE1C) and poly (ADP-ribose) polymerase family member 2 (PARP2) and chromatin assembly factor 1 subunit B (CHAF1B). Genes involved in cell differentiation, namely epithelial membrane protein 2 (EMP2), germ cell-less homolog 1 (GMCL1) and BarH-like homeobox 1 (BARX1) were down regulated in the MCF-12A cells. Bioinformatics analyses are currently being performed on microarray techniques conducted using 4x44K whole human genome slides to confirm results and to contribute to the knowledge of the in vitro influence of non-thermal 900 MHz mobile phone radiation on signal transduction.