Differentiation of K562 Cells Under ELF-EMF Applied at Different Time Courses

Abstract

The time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF.

Comparative Analysis of Biological Effects Induced on Different Cell Types by Magnetic Fields with Magnetic Flux Densities in the Range of 1–60 mT and Frequencies up to 50 Hz

“…The maximum possible exposure near a specific source often differs by some orders of magnitude from the average individual exposure of a person. For example, at 5 cm from a vacuum cleaner, B is of about 40 µT, but at 1 m it will be around 0.2 µT [9,10]; • alternation and duration of exposure [5][6][7][11][12][13].…”

Expression levels of PDYN and OPRM1 genes in SH-SY5Y cells exposed to 50 Hz electromagnetic field

“…Previous studies have demonstrated that ELF-EMF is associated with production of ROS. [16][17][18] Moreover, reduced PDYN expression in the human brain is associated with opiate dependency. 35,36 Interestingly, in the present study the continuous exposure condition of ELF-EMF was associated with the lower expression levels of the PDYN.…”

“…15 It has been reported that ELF-EMF enhanced production of reactive oxygen species (ROS). [16][17][18] Cells maintain redox balance through production of ROS and cellular antioxidant capacity. The altered balance between generation and elimination of ROS plays a critical role in a variety of multifactorial complex traits including neurodegenerative diseases.…”

Effect of ELF-EMF on antioxidant status and micronuclei in K562 cells and normal lymphocytes

“…Namely, application of ELF-EMF once at the onset of hemin induction may have interfered with the differentiation process and led to a decrease in differentiation as a result of increased oxidative stress and consequent MAPK signal path activation, while daily ELF-EMF application overcame this effect by an increase in HSP levels. It is debated that the time course of application and the duration may be of a nonlinear character suggesting a ''window'' effect in duration of the field application [8].…”

“…The increase in heat-shock protein levels induced by ELF-EMF is not able to reverse the increase in the number of apoptotic cells caused by oxidative stress [7]. Based on the results of Ayse and co-workers about influence of ELF-EMF on differentiation of K562 cancer cell line, it can be concluded that ELF-EMF exposure at different timecourses results in different outcomes [8].…”