Medical/biological study (experimental study)

Effect of 50 Hz magnetic field exposure on neuroblastoma morphology med./bio.

By: Pozzi D, Grimaldi S, Ledda M, De Carlo F, Modesti A, Scarpa S, Foletti A, Lisi A

Published in: Int J Integr Biol 2007; 1 (1): 12-17

Aim of study (acc. to author)

The effects of an acute in vitro exposure of neuroblastoma cells to a 50 Hz magnetic field on differentiation and proliferation processes should be investigated.

Background/further details

Cell growth tests were repeated three times. Neurofilaments are components of the neural cytoskeleton und NF160 and NF200 are two common types.

Endpoint

cell viability/cell division/proliferation: differentiation and proliferation of neuroblastoma cells

Exposure

- 50 Hz
- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 5 days	magnetic flux density: 2 mT effective value

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 5 days

Exposure setup

Exposure source	solenoid
Chamber	cells were placed in 5 ml Corning flasks in the exposure area
Setup	solenoid consisting of a 2 cm thick, 20 cm high asbestos cylinder with a diameter of 20 cm and 1200 turns of 2 mm diameter copper wire wound in three layers in continuous forward-backward fashion; solenoid placed inside a cell incubator, the centre of which was ventilated by a fan to guarantee a constant temperature; magnetic field homogenuos within 5% in the 11 cm x 17 cm exposure area along the solenoid's axis
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	2 mT	effective value	measured	-	-

Additional parameter details

vertical ambient geomagnetic field = 32 µT horizontal ambient geomagnetic field = 16 µT stray ambient AC field < 0.1 µT

Reference articles

Santoro N et al. (1997): Effect of extremely low frequency (ELF) magnetic field exposure on morphological and biophysical properties of human lymphoid cell line (Raji)
Stauffer PR et al. (1994): Practical induction heating coil designs for clinical hyperthermia with ferromagnetic implants

Exposed system:

intact cell/cell culture
LAN-5 cells (human neuroblastoma cell line)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: neurofilament synthesis (detection of NF160 and NF200 with immunofluorescence, microscopy), expression of heat shock proteins (Western Blot)
cell viability/cell division/proliferation: cell growth curves (living cell count after 3,4 and 5 days of exposure, trypan blue staining, microscopy)
morphol./histopathol. changes: cell morphology (phase contrast microscopy, scanning electron microscopy)

Investigated system:

isolated bio./chem. substance
intact cell/cell culture

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

Cell growth was significantly decreased in exposed cell cultures compared to sham exposure (comment from EMF-Portal editorial office: the graph shows an increase in cell growth - a contradiction). Moreover, morphology of exposed cells was strikingly altered by a stretched appearance with axon-like structures and blebs. Finally, higher levels of neurofilaments NF160 and NF200 could be observed in exposed cells via immunofluorescence tests.
The authors conclude that the results indicate that an acute in vitro exposure of neuroblastoma cells to a 50 Hz magnetic field decreases their growth rate and changes the cell morphology towards a neuronal cell like form. However, these results were not evaluated in any form.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro (ISPESL; National Institute for Occupational Safety and Prevention), Italy
NAMED, Italy

Martínez MA et al. (2019): Involvement of the EGF Receptor in MAPK Signaling Activation by a 50 Hz Magnetic Field in Human Neuroblastoma Cells
Su L et al. (2017): The effects of 50 Hz magnetic field exposure on DNA damage and cellular functions in various neurogenic cells
Martinez MA et al. (2016): Power Frequency Magnetic Fields Affect the p38 MAPK-Mediated Regulation of NB69 Cell Proliferation Implication of Free Radicals
Falone S et al. (2016): Improved Mitochondrial and Methylglyoxal-Related Metabolisms Support Hyperproliferation Induced by 50 Hz Magnetic Field in Neuroblastoma Cells
Benassi B et al. (2016): Extremely low frequency magnetic field (ELF-MF) exposure sensitizes SH-SY5Y cells to the pro-Parkinson's disease toxin MPP+
Cheng Y et al. (2015): Extremely low-frequency electromagnetic fields enhance the proliferation and differentiation of neural progenitor cells cultured from ischemic brains
Seong Y et al. (2014): Egr1 mediated the neuronal differentiation induced by extremely low-frequency electromagnetic fields
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Bae JE et al. (2013): Electromagnetic field-induced converse cell growth during a long-term observation
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Pirozzoli MC et al. (2003): Effects of 50 Hz electromagnetic field exposure on apoptosis and differentiation in a neuroblastoma cell line
Yoshizawa H et al. (2002): No effect of extremely low-frequency magnetic field observed on cell growth or initial response of cell proliferation in human cancer cell lines
Tofani S et al. (2001): Static and ELF magnetic fields induce tumor growth inhibition and apoptosis
Glück B et al. (2001): Inhibition of proliferation of human lymphoma cells U937 by a 50 Hz electromagnetic field
Loberg LI et al. (2000): Cell viability and growth in a battery of human breast cancer cell lines exposed to 60 Hz magnetic fields