الفهرس 
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Abstract
The present study aims to compare the effect of the exposure of different frequencies
of AC electric field on the permeability and viability of tumor cells. The experiment was
carried out on eight similar hepatocellular carcinoma HEPG2 cell lines with complete
medium of DMEM low glucose with l-glutamate, FBS (10%), and penicillin streptomycin
(1%). After the exposure the cells were incubated for 48 hours at conditions 37 °C in a
humidified CO2 incubator containing 5% CO2, and then we tested viability and permeability
parameters.
A pilot study was done to determine the most effective AC exposure time which was
determined by comparing the viability of the cell line after exposure times 5, 10, and 15
minutes. This pilot study resulted in choosing 5 minutes as the time of AC exposure, the cell
line was splitted and subdivided into eight main groups:
Control group (G0): Cells wasn’t exposed to the electric field.
G1: five minutes exposure of AC with frequency 1 Hz.
G2: five minutes exposure of AC with frequency 10 Hz.
G3: five minutes exposure of AC with frequency 10
2 Hz.
G4: five minutes exposure of AC with frequency 10
3 Hz.
G5: five minutes exposure of AC with frequency 10
4 Hz.
G6: five minutes exposure of AC with frequency 10
5 Hz.
G7: five minutes exposure of AC with frequency 10
6 Hz.
Viability test of the cell lines were determined by the flow cytmoter FACScan after
staining the cell lines with Annexin v and PI to count and asses the number of living and dead
(early apoptotic, late apoptotic, and necrotic) cells. The viability results were presented as
percent of living/dead cells in each group.
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All the exposed groups have a great reduction in the living cells compared to control
group. It is noticed that the highest anti-tumoral effect of the examined frequency range is
maximum at 10 KHz and 100 KHz.
Permeability of all groups was monitored by Leica fluorescent microscope with the two
fluorescent stains HOECHST 33342 and PI which used for nuclei staining and membrane
integrity respectively. The fluorescence intensity was measured five times each group by the
software program image J. All the exposed groups have a great reduction in the HOECHST
33342 intensity compared to control group and a great increase in the intensity of PI
compared to control group.
The genetic effect of the AC different frequencies exposure was measured by the
quantitative real time PCR of cyclins A, B, and E and the house keeping gene GADPH.
Although there was no significance in cyclin A and B, cyclin E was significantly reduced in
the exposed group compared to the control group which is involved in many biological
processes in the hepatocarcinogenesis like uncontrolled cell growth, invasion, and DNA
damage.
The capacitance and the resistance of cells were measured by LCR meter for all groups
and the dielectric constant (relative permittivity) and the conductivity were calculated to
represent the dielectric properties of the cell lines after the exposure.
The relative permittivity and the conductivity of the groups were increased compared to
the control group which reflects the image of different current paths and the different
dispersions outside / inside the cells according to the frequency of exposure.