Effect of extremely low frequency magnetic fields on cell proliferation and gene expression

TLDR

Extremely low frequency magnetic fields (ELF‑MF) have been studied for potential biological effects, yet controversies remain. This study examined ELF‑MF effects on proliferation, viability, DNA synthesis, and gene expression in MCF10A, MCF7, Jurkat, and NIH3T3 cells. Cells were exposed to 1 mT at 60 Hz for 4 or 16 h, then proliferation, viability, DNA synthesis, and cell death were measured; MCF7 cells were also exposed to 2 mT for 16 h for transcriptomic analysis. ELF‑MF caused significant reductions in cell number, viability, and DNA synthesis in MCF10A and MCF7 but not in Jurkat or NIH3T3, and up‑regulated PMAIP1 in MCF7, indicating cell‑context‑specific cell‑cycle delay.

Abstract

Owing to concerns regarding possible effects of extremely low frequency magnetic fields (ELF-MF) on human health, many studies have been conducted to elucidate whether ELF-MF can induce modifications in biological processes. Despite this, controversies regarding effects of ELF-MF are still rife. In this study, we investigated biological effects of ELF-MF on MCF10A, MCF7, Jurkat, and NIH3T3 cell lines. ELF-MF with a magnetic flux density of 1 mT at 60 Hz was employed to stimulate cells for 4 or 16 h, after which the effects of ELF-MF on cell proliferation, cell death, cell viability, and DNA synthesis rates were assessed. Whereas Jurkat and NIH3T3 cells showed no consistent variation in cell number, cell viability, and DNA synthesis rate, MCF10A and MCF7 cells showed consistent and significant decreases in cell number, cell viability, and DNA synthesis rates. However, there was no effect of ELF-MF on cell death in any of tested cell lines. Next, to investigate the effect of ELF-MF on gene expression, we exposed MCF7 cells to 2 mT at 60 Hz for 16 h and examined transcriptional responses by using gene expression array. We found a gene, PMAIP1, that exhibited statistically significant variation using two-fold cut-off criteria and certified its expression change by using semi-quantitative and quantitative reverse transcription polymerase chain reaction. From these results, we concluded that ELF-MF could induce the delay of cell cycle progression in MCF7 and MCF10A cells in a cell context-specific manner and could up-regulate PMAIP1 in MCF7 cells.