Medical/biological study (experimental study)

Lung cancer A549 cells migrate directionally in DC electric fields with polarized and activated EGFRs med./bio.

By: Yan X, Han J, Zhang Z, Wang J, Cheng Q, Gao K, Ni Y, Wang Y

Published in: Bioelectromagnetics 2009; 30 (1): 29-35

Aim of study (acc. to editor)

To study the effect of DC electric fields on migration direction (galvanotaxis) of lung cancer cells, and the role of epidermal growth factor receptors (EGFR).

Background/further details

The EGFR inhibitors cetuximab and AG1478 were used to test the possible involvement of EGFR activity in galvanotactic reaction. To explore the mechanism through which DC electric fields stimulate the migration of A549 cells, the authors investigated the involvement of EGFR downstream signaling pathways ERK and AKT.

Endpoint

galvanotaxis

Exposure

- 0 Hz
- DC
- electric current application

Exposure	Parameters
Exposure 1: DC/static Exposure duration: continuous for 2 hours	electric field strength: 3 V/cm

Exposure 1

Main characteristics

Frequency	DC/static
Type	electric current
Exposure duration	continuous for 2 hours

Exposure setup

Exposure source	electrode
Chamber	32 mm x 8 mm x 0.12 mm glass chamber or 60 mm x 15 mm x 0.12 mm glass chamber
Setup	silver/silver chloride electrodes
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	3 V/cm	-	measured	-	-

Exposed system:

intact cell/cell culture
A549 (human adenocarcinoma cell line)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: activation and phosphorylation of ERK and AKT (Western blot)
galvanotaxis (displacement response; phase contrast microscopy) and distribution of epidermal growth factor receptors and F-actin on the cells (immunofluorescence assay)

Investigated system:

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

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

A549 cells migrated toward the cathode in applied DC electric fields at 3 V/cm. Both epidermal growth factor receptors and F-actin are polarized to the cathode (i.e. stronger staining of EGFRs at the cathodal side of the plasma membrane). EGFR inhibitors (cetuximab and AG1478) reduced the migration rate and directed motility in DC electric fields. ERK and AKT signaling pathways were prominently promoted by the electric field. EGFR inhibitors could reduce this promotion but not completely.
These findings suggest that polarization of EGFRs and the activation of their downstream signals play an important role in the galvanotaxis of A549 cells in DC electric fields.

Study character:

medical/biological study
experimental study
full/main study

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