Medical/biological study (experimental study)

The expression and intranuclear distribution of nucleolin in HL-60 and K-562 cells after repeated, short-term exposition to rotating magnetic fields med./bio.

By: Masiuk M, Rakoczy R, Masiuk S, Kordas M

Published in: Int J Radiat Biol 2008; 84 (9): 752-760

Aim of study (acc. to author)

To study the influence of rotating magnetic fields on the expression and intra-nuclear distribution of nucleolin (a protein involved e.g. in ribosome biosynthesis) in two human cell lines.

Endpoint

molecular biosynthesis: nucleolin expression and its intra-nuclear distribution

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 35 Hz Exposure duration: 30 min with an interval of 24 h on 4 days	magnetic flux density: 10 mT mean
Exposure 2: 50 Hz Exposure duration: 30 min with an interval of 24 h on 4 days	magnetic flux density: 20 mT mean

Exposure 1

Main characteristics

Frequency	35 Hz
Type	magnetic field
Exposure duration	30 min with an interval of 24 h on 4 days
Additional info	rotating field

Exposure setup

Exposure source	generator made of the stator of a 3-phase induction squirrel-cage motor
Setup	water-filled glass container with the cultur flasks placed inside the stator

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	10 mT	mean	calculated	-	-

Exposure 2

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	30 min with an interval of 24 h on 4 days
Additional info	rotating field

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	20 mT	mean	calculated	-	-

Reference articles

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
Cridland NA et al. (1999): 50 Hz magnetic field exposure alters onset of S-phase in normal human fibroblasts
Schimmelpfeng J et al. (1997): Action of a 50 Hz magnetic field on proliferation of cells in culture

Exposed system:

intact cell/cell culture
HL-60 (human acute myeloid leukaemia cells), K-562 (chronic myelogenous leukemia)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: nucleolin expression (in nucleus and in nucleolin aggregates) and intra-nuclear distribution (cytospin sildes; laser scanning cytometry)
cell viability/cell division/proliferation: cell cycle stages

Investigated system:

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

Time of investigation:

after exposure

Main outcome of study (acc. to author)

In both cell lines repeated short-term exposure to rotating magnetic fields induced significant increase in nucleolin expression in the whole nucleus and in nucleolin aggregates. This effect seemed to be frequency-dependent for K-562 cells while the increase of nucleolin expression in HL-60 cells was higher at the lower frequency. No significant changes in cell cycle phases in both cell lines after exposure were found. This indicates that changes of nucleolin expression induced by rotating magnetic fields are not related to cell cycle.
In conclusion, the nucleolin is responsive to rotating magnetic fields in HL-60 and K-562. The increase of its expression may indicate a reaction of cells to rotating magnetic fields and it may influence other biological properties.

Study character:

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

Study funded by

Foundation for Polish Science (FNP), Poland

Simko M et al. (2004): Extremely low frequency electromagnetic fields as effectors of cellular responses in vitro: possible immune cell activation
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
Lange S et al. (2002): Alterations in the cell cycle and in the protein level of cyclin D1, p21CIP1, and p16INK4a after exposure to 50 Hz MF in human cells
Lacy-Hulbert A et al. (1998): Biological responses to electromagnetic fields
Schimmelpfeng J et al. (1997): Action of a 50 Hz magnetic field on proliferation of cells in culture

The expression and intranuclear distribution of nucleolin in HL-60 and K-562 cells after repeated, short-term exposition to rotating magnetic fields med./bio.

Aim of study (acc. to author)

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Exposure 2

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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