Medical/biological study (experimental study)

Regulating genes with electromagnetic response elements med./bio.

By: Lin H, Blank M, Rossol-Haseroth K, Goodman R

Published in: J Cell Biochem 2001; 81 (1): 143-148

Aim of study (acc. to author)

To investigate whether insertion of "electromagnetic field respone elements" (EMREs) mediates the ability to respond to magnetic fields.

Background/further details

Switching "on" and "off" of genes would be a useful tool in gene therapy. In the present study, the possibility was examined to increase the enzyme activity via the insertion of DNA sequences which are sensitive to magnetic fields.
Promoter sequences consisting of cytosine and thymine seem to act as so called "electromagnetic field response elements" (EMREs). Segments of 900 base pairs of the c-myc promoter, containing these EMREs were cloned into constructs of catalase or luciferase, which are otherwise unresponsive to electromagnetic fields. Those constructs were transfected into HeLa cells.
Enzyme activity was measured 30 minutes after a 30 minutes-exposure period. Five groups were examined: 1.) exposed transfected HeLa cells, 2.) sham exposed transfected HeLa cells, 3.) exposed transfected HeLa cells, but without the 900 base pairs of the c-myc promoter containing the EMREs, 4.) non-specific protein samples as a negative control and 5.) at 43°C heat shocked HeLa cells as a positive control.

Endpoint

cell function: enzyme activity of catalase and luciferase

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 30 minutes	magnetic flux density: 8 µT electric field strength: 11 µV/m

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 30 minutes

Exposure setup

Exposure source	Helmholtz coils
Setup	cells in a Plexiglas stand in horizontal position; Helmholtz coils consisted of 19 gauge wire bundles, wound in 164 rectangular turns around a rectangular form (13 x 14 cm) with 8 cm spacing; coils were closed within mu-metal containers for shielding (30 cm high, 15 cm diameter cylindrical container)
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8 µT	-	measured	-	-
electric field strength	11 µV/m	-	calculated	-	-

Reference articles

Lin H et al. (1999): A magnetic field-responsive domain in the human HSP70 promoter
Lin H et al. (1998): Magnetic field activation of protein-DNA binding
Lin H et al. (1998): Myc-mediated transactivation of HSP70 expression following exposure to magnetic fields
Jin M et al. (1997): Biological and technical variables in myc expression in HL60 cells exposed to 60 Hz electromagnetic fields

Exposed system:

intact cell/cell culture
HeLa cell line (human adenocarcinoma cell line), transfected

Methods Endpoint/measurement parameters/methodology

cell function: enzyme activity of catalase (radioactive labeling) and luciferase (commercial kit)

Investigated system:

isolated bio./chem. substance

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Transfected cells exposed to a 60 Hz-magnetic field (group 1) showed significantly increased enzyme activities of catalase and luciferase in comparison to sham exposed transfected cells (group 2), while no increased enzyme activities were measured in transfected cells without the c-myc-promoter containing the EMREs (group 3).
The data indicate that the regulation of genes could be possible via the insertion of DNA sequences which are sensitive to magnetic fields.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

Replication studies

Rodriguez de la Fuente AO et al. (2009): Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: An in vitro study

Heredia-Rojas JA et al. (2010): Effect of 60 Hz magnetic fields on the activation of hsp70 promoter in cultured INER-37 and RMA E7 cells
Rodriguez de la Fuente AO et al. (2009): Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: An in vitro study
Goodman R et al. (2009): Extremely low frequency electromagnetic fields activate the ERK cascade, increase hsp70 protein levels and promote regeneration in Planaria
Morehouse CA et al. (2000): Exposure of Daudi cells to low-frequency magnetic fields does not elevate MYC steady-state mRNA levels
Lin H et al. (1999): A magnetic field-responsive domain in the human HSP70 promoter
Jahreis GP et al. (1998): Absence of 60-Hz, 0.1-mT magnetic field-induced changes in oncogene transcription rates or levels in CEM-CM3 cells
Lin H et al. (1998): Magnetic field activation of protein-DNA binding
Lin H et al. (1998): Myc-mediated transactivation of HSP70 expression following exposure to magnetic fields
Jin M et al. (1997): Biological and technical variables in myc expression in HL60 cells exposed to 60 Hz electromagnetic fields
Lin H et al. (1996): Electromagnetic field stimulation of biosynthesis: changes in c-myc transcript levels during continuous and intermittent exposures
Miyakoshi J et al. (1996): Exposure to magnetic field (5 mT at 60 Hz) does not affect cell growth and c-myc gene expression
Lin H et al. (1994): Specific region of the c-myc promoter is responsive to electric and magnetic fields
Phillips JL et al. (1992): Magnetic field-induced changes in specific gene transcription