Yonsei Med J.  2006 Dec;47(6):852-861. 10.3349/ymj.2006.47.6.852.

Effects of Sinusoidal Electromagnetic Field on Structure and Function of Different Kinds of Cell Lines

• Sul AR
• Park SN
• Suh H

• KMID: 1777176
• DOI: http://doi.org/10.3349/ymj.2006.47.6.852

Abstract

This study investigated that whether a 2 mT, 60 Hz, sinusoidal electromagnetic field (EMF) alters the structure and function of cells. This research compared the effects of EMF on four kinds of cell lines: hFOB 1.19 (fetal osteoblast), T/G HA-VSMC (aortic vascular smooth muscle cell), RPMI 7666 (B lymphoblast), and HCN-2 (cortical neuronal cell). Over 14 days, cells were exposed to EMF for 1, 3, or 6 hours per day (hrs/d). The results pointed to a cell type-specific reaction to EMF exposure. In addition, the cellular responses were dependent on duration of EMF exposure. In the present study, cell proliferation was the trait most sensitive to EMF. EMF treatment promoted growth of hFOB 1.19 and HCN-2 compared with control cells at 7 and 14 days of incubation. When the exposure time was 3 hrs/d, EMF enhanced the proliferation of RPMI 7666 but inhibited that of T/G HA- VSMC. On the other hand, the effects of EMF on cell cycle distribution, cell differentiation, and actin distribution were unclear. Furthermore, we hardly found any correlation between EMF exposure and gap junctional intercellular communication in hFOB 1.19. This study revealed that EMF might serve as a potential tool for manipulating cell proliferation.

Keyword

Electromagnetic field; fetal osteoblast; aortic vascular smooth muscle cell; B lymphoblast; cortical neuronal cell; proliferation

MeSH Terms

Signal Transduction
Microfilaments/radiation effects
Humans
Gap Junctions/metabolism/radiation effects
*Electromagnetic Fields
Cell Proliferation/radiation effects
Cell Physiology/*radiation effects
Cell Line
Cell Differentiation/radiation effects
Cell Cycle/radiation effects

Figure

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  Fig. 1 EMF exposure system. (A) Control part. (B) Placement of the system and position of the sample in a cell culture incubator. (C) Magnified view of the experimental setup.

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  Fig. 2 Proliferation of hFOB 1.19 cells. After 7 and 14 days of incubation, cell numbers of the control (No EMF Exposure) and EMF-treated (2 mT) groups was quantified by hexosaminidase assay. The bars represent the mean ± SD (n = 7; *p < 0.05).

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  Fig. 3 Proliferation of T/G HA-VSMC cells. After 7 and 14 days of incubation, cell numbers of the control (No EMF Exposure) and EMF-treated (2 mT) groups was quantified by hexosaminidase assay. The bars represent the mean ± SD (n = 4; *p < 0.05).

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  Fig. 4 Proliferation of RPMI 7666 cells. After 7 and 14 days of incubation, cell numbers of the control (No EMF Exposure) and EMF-treated (2 mT) groups was quantified by hexosaminidase assay. The bars represent the mean ± SD (n = 4; *p < 0.05).

• 

  Fig. 5 Proliferation of HCN-2 cells. After 7 and 14 days of incubation, cell numbers of the control (No EMF Exposure) and EMF-treated (2 mT) groups was quantified by hexosaminidase assay. The bars represent the mean ± SD (n = 5; *p < 0.05).

• 

  Fig. 6 Cell cycle distribution of hFOB 1.19 cells. After 7 (A) and 14 (B) days of incubation, cells from the control (No EMF Exposure) and EMF-treated (2 mT) groups were analyzed by flow cytometry. The bars represent the mean ± SD (n = 5; *p < 0.05).

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  Fig. 7 Cell cycle distribution of T/G HA-VSMC cells. After 7 (A) and 14 (B) days of incubation, cells from the control (No EMF Exposure) and EMF-treated (2 mT) groups were analyzed by flow cytometry. The bars represent the mean ± SD (n = 4; *p < 0.05, **p < 0.005).

• 

  Fig. 8 Cell cycle distribution of RPMI 7666 cells. After 7 (A) and 14 (B) days of incubation, cells from the control (No EMF Exposure) and EMF-treated (2 mT) groups were analyzed by flow cytometry. The bars represent the mean ± SD (n = 3; *p < 0.05, **p < 0.005).

• 

  Fig. 9 Cell cycle distribution of HCN-2 cells. After 7 (A) and 14 (B) days of incubation, cells from the control (No EMF Exposure) and EMF-treated (2 mT) groups were analyzed by flow cytometry. The bars represent the mean ± SD (n = 4; *p < 0.05).

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  Fig. 10 ALP activity of hFOB 1.19 cells. After 7 and 14 days of incubation, ALP activities from the control (No EMF Exposure) and EMF-treated (2 mT) groups were calculated. The bars represent the mean ± SD (n = 4; *p < 0.05).

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  Fig. 11 Confocal microscopy analysis of HCN-2 cells. Distribution of actin filaments was visualized for control (A, B) and 42 hour-EMF-treated (C, D) cells. Scale bar, 50 µm.

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  Fig. 12 GJIC in hFOB 1.19 cells. Fluorescence microscopy analysis of Cx43 was performed for control (A) and 42 hour-EMF-treated (B) cells. Scale bar, 100 µm. (C) Western blotting (C) and densitometric (D) analyses were carried out with anti-GAPDH and anti-Cx43. The Cx43/GAPDH ratio of the control group was normalized to 1. The bars represent the mean ± SD (n = 3).

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