Therapeutical study (experimental study)

The effect of 100 Hz magnetic field combined with X-ray on hepatoma-implanted mice med./bio.

By: Wen J, Jiang S, Chen B

Published in: Bioelectromagnetics 2011; 32 (4): 322-324

To study the possible synergism between 100 Hz magnetic field exposure and X-rays in terms of their influence on tumor growth inhibition and survival time in tumor-bearing mice.

Implanted tumors were allowed to grow for 7-14 days until the tumor diameter reached the size of 2 cm before treatment was started.
Mice were divided into six groups (n = 10): 1) sham X-ray and five periods of sham exposure to magnetic field (each period = 60 min with an interval of 12 h); 2) sham X-ray and five periods of 100 Hz magnetic field exposure; 3) 4 Gy X-ray followed (within half an hour) by five periods of sham exposure to magnetic fields; 4) 8 Gy X-ray followed by five periods of sham exposure; 5) 4 Gy X-rays followed by five periods of magnetic field exposure; and 6) 8 Gy X-ray followed by five periods of magnetic field exposure.
Additionally, to study whether more magnetic field exposure periods could have a greater synergistic effect with X-rays than fewer periods, three groups of tumor-bearing mice were examined (n = 20): 1) 4 Gy X-rays followed by five periods of sham exposure; 2) 4 Gy X-ray followed by three periods magnetic field exposure and two periods of sham exposure; and 3) 4 Gy X-rays followed by five periods of magnetic field exposure.

Exposure	Parameters
Exposure 1: 100 Hz Exposure duration: 3 or 5 times 60 min with a 12 h interval between them	magnetic flux density: 0.7 mT mean

Frequency	100 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	3 or 5 times 60 min with a 12 h interval between them
Additional info	animals were treated in different groups: i) sham X-ray exposure + 5 times sham EMF exposure ii) sham X-ray exposure + 5 times EMF exposure iii) 4 Gy X-ray exposure + 5 times sham EMF exposure iv) 8 Gy X-ray exposure + 5 times sham EMF exposure v) 4 Gy X-ray exposure + 5 times EMF exposure vi) 8 Gy X-ray exposure + 5 times EMF exposure vii) 4 Gy X-ray exposure + 3 times EMF exposure + 2 times sham EMF exposure

Exposure source	solenoid
Setup	15 cm x 20 cm solenoid with 270 turns of 2 mm diameter copper wire wound in three layers; mouse anesthetized and placed inside the solenoid
Sham exposure	A sham exposure was conducted.

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.7 mT	mean	measured	-	-

Exposed system:

animal
mouse/BALB/c (implanted subcutaneously with hepatocellular carcinoma cells H22 (under axillary fossa))
whole body

Investigated system:

Time of investigation:

The data showed that five periods of combined 100 Hz magnetic field exposure and 4 Gy X-ray could significantly extend the overall days of survival and reduce the tumor size compared to magnetic field exposure or X-ray alone. Furthermore, a greater number of magnetic field exposure periods (5 compared to 3) could further improve the survival and inhibit tumor growth in hepatoma-implanted mice when combined with 4 Gy X-ray.
In conclusion, these findings suggest that 100 Hz magnetic fields could possibly synergize with 4 Gy X-ray in terms of survival improvement and tumor inhibition in hepatoma-implanted mice.

Study character:

Delle Monache S et al. (2013): Inhibition of angiogenesis mediated by extremely low-frequency magnetic fields (ELF-MFs)
Berg H et al. (2010): Bioelectromagnetic field effects on cancer cells and mice tumors
Jian W et al. (2009): X-ray-induced apoptosis of BEL-7402 cell line enhanced by extremely low frequency electromagnetic field in vitro
Novikov VV et al. (2009): Effect of weak combined static and extremely low-frequency alternating magnetic fields on tumor growth in mice inoculated with the Ehrlich ascites carcinoma
Kirson ED et al. (2007): Alternating electric fields arrest cell proliferation in animal tumor models and human brain tumors
Huang L et al. (2006): Effects of sinusoidal magnetic field observed on cell proliferation, ion concentration, and osmolarity in two human cancer cell lines
Yamaguchi S et al. (2004): The effect of repetitive magnetic stimulation on the tumor development
Tofani S et al. (2002): Increased mouse survival, tumor growth inhibition and decreased immunoreactive p53 after exposure to magnetic fields
Tofani S et al. (2001): Static and ELF magnetic fields induce tumor growth inhibition and apoptosis
Williams CD et al. (2001): Therapeutic electromagnetic field effects on angiogenesis and tumor growth