Effect of millimeter wave irradiation on tumor metastasis

Abstract

One of the major side effects of chemotherapy in cancer treatment is that it can enhance tumor metastasis due to suppression of natural killer (NK) cell activity. The present study was undertaken to examine whether millimeter electromagnetic waves (MMWs) irradiation (42.2 GHz) can inhibit tumor metastasis enhanced by cyclophosphamide (CPA), an anticancer drug. MMWs were produced with a Russian-made YAV-1 generator. Peak SAR and incident power density were measured as 730 +/- 100 W/kg and 36.5 +/- 5 mW/cm(2), respectively. Tumor metastasis was evaluated in C57BL/6 mice, an experimental murine model commonly used for metastatic melanoma. The animals were divided into 5 groups, 10 animals per group. The first group was not given any treatment. The second group was irradiated on the nasal area with MMWs for 30 min. The third group served as a sham control for group 2. The fourth group was given CPA (150 mg/kg body weight, ip) before irradiation. The fifth group served as a sham control for group 4. On day 2, all animals were injected, through a tail vein, with B16F10 melanoma cells, a tumor cell line syngeneic to C57BL/6 mice. Tumor colonies in lungs were counted 2 weeks following inoculation. CPA caused a marked enhancement in tumor metastases (fivefold), which was significantly reduced when CPA-treated animals were irradiated with MMWs. Millimeter waves also increased NK cell activity suppressed by CPA, suggesting that a reduction in tumor metastasis by MMWs is mediated through activation of NK cells.

Millimeter wave radiation induces apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 human chondrosarcoma cells

“…Previously studies demonstrated millimeter wave radiation in treatment for various types of malignant tumors. The main indications for this therapy are prevention of metastases, relapses, and dissemination of the tumor; prevention and treatment of side-effects and complications from chemotherapy and radiotherapy; and treatment of the paraneoplastic syndrome (6,7). However, the molecular mechanism of millimeter wave radiation therapeutic effect is not well understood.…”

Effect on Tumoral Cells of Low Intensity Electromagnetic Waves

“…Unlike ionizing X-and γ-rays, the method proposed here is non-ionizing and hence is completely deprived of any harmful side effects. In [9][10][11][12], the influence of millimeter electromagnetic waves (MMWs) on various tumors has been investigated. The present study was undertaken to investigate whether low-intensity (nonthermal) MMWs at 42.2 GHz can act on tumor of mice in vivo without cytostatic agents.…”

Evaluation of the Potential In Vitro Antiproliferative Effects of Millimeter Waves at Some Therapeutic Frequencies on RPMI 7932 Human Skin Malignant Melanoma Cells

“…In these cases, they are generally applied on human skin on various zones of the body and also in correspondence to some acupuncture points. Though such studies have in most cases qualitative character, recently, quantitative evidence has been reported on the physiologic mechanism of action of MMWs on the human body that could account for many in vivo MMWs-induced effects such as pain relief [17][18][19] or anticancer activity [16,20,21]. On the other hand, some in vitro evidence of the antiproliferative action of low power MMWs has been reported previously on different tumoral cell culture systems [22][23][24][25].…”