Electrotaxis of lung cancer cells in a multiple-electri

c-field chip

Speaker: Ching Wen Huang

Adviser: Ji Yen Cheng

2009.01.21

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Historical Background

The common origins of Electrophysiology and Bioelectricity

Leydon jar

(徐在新 , 從法拉第到麥克斯韋 , 凡異出版社 )

(C.D. MaCaig, Physiol Rev., vol. 85, July 2005)

Electrotaxis (galvanotaxis):

Movement of organisms or cell

s in response to an electric field.

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Physiological Electric Field (EF):

About 1~100mV/mm,

existing in wound, embryo’s

skin, interface between tumor

and normal tissue, etc.

(C.D. MaCaig, Physiol Rev., vol. 85, July 2005)

+ -Power supply

Design features:

1. Defined geometry of culture chamber

2. Agar-gelled salt bridges

Device for electrotaxis study (McCaig et al.)

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Shortcomings:

1. large chamber size

2. not well-sealed

3. bulky(B. Song, Nature Protocols, vol. 2(6), 2007)

Our electrotactic chipAdvantages:

1. well-sealed

2. negligible Joule heating

3. Multiple EF strengths

I

σ*W*h

EF strength =

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Our Electrotactic Device

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Cell Migration under EF

+- EF

Lung cancer cells:

CL1-0 – weak metastasis / no response

CL1-5 – high metastasis / move

toward the anode

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CL1-0

CL1-5

0mV/mm 75mV/mm 210mV/mm 340mV/mm

Response 2: Cell Orientation under EF

+- EF

before treating treating 7hr

Under the applied EF, obvious orientation of

CL1-5 perpendicular to the direction of EF is

shown.

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Possible Mechanism

A physiological EF physically moves charged receptor

molecules exposed on the outer surface of the lipid bilayer

and creates receptor asymmetry between cathodal- and an

odal-facing membranes.

EGFR on corneal epithelial cells

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Conclusion & Future Work

1. A well-sealed electrotactic chip which can provide multiple

EF strengths was designed and fabricated.

2. Positive correlation between metastasis and electrotaxis o

f lung cancer cells was observed.

3. The orientation of CL1-5 was observed following the migra

tion, implying different signal pathway triggered by physio

logical EF

4. Surface proteins which are related to metastasis of lung c

ancer will be studied under physiological EF.

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Thanks for

your attention