Human promyelocytic leukemia HL-60 cells were pre-exposed to non-ionizing 900 MHz radiofrequency fields (RF) at 12 μW/cm2 power density for 1 hour/day for 3 days and then treated with a chemotherapeutic drug, doxorubicin (DOX, 0.125 mg/L). Several end-points related to toxicity, viz., viability, apoptosis, mitochondrial membrane potential (MMP), intracellular free calcium (Ca2+) and Ca2+-Mg2+ -ATPase activity were measured. The results obtained in un-exposed and sham-exposed control cells were compared with those exposed to RF alone, DOX alone and RF+DOX. The results indicated no significant differences between un-exposed, sham-exposed control cells and those exposed to RF alone while treatment with DOX alone showed a significant decrease in viability, increased apoptosis, decreased MMP, increased Ca2+ and decreased Ca2+-Mg2+-ATPase activity. When the latter results were compared with cells exposed RF+DOX, the data showed increased cell proliferation, decreased apoptosis, increased MMP, decreased Ca2+ and increased Ca2+-Mg2+-ATPase activity. Thus, RF pre-exposure appear to protect the HL-60 cells from the toxic effects of subsequent treatment with DOX. These observations were similar to our earlier data which suggested that pre-exposure of mice to 900 MHz RF at 120 μW/cm2 power density for 1 hours/day for 14 days had a protective effect in hematopoietic tissue damage induced by subsequent gamma-irradiation.
References
[1]
(2012) Section of cancer information. International Agency for Cancer Research/WHO. GLOBOCAN 2008 website. Available: http://www.iarc.fr/en/research-groups/se？c1/index.php. Accessed: 2 September 2012.
[2]
(2012) Cancer facts and 2012. American Cancer Society website. Available: http://www.cancer.org/acs/groups/content？/epidemiologysurveilance/documents/docum？ent/acspc-031941.pdf. Accessed: 2 September 2012.
[3]
Comparisons F (2010) Drug Facts and Comparisons. Lippincott Williams & Wilkins. 3408 p.
[4]
Beer MH, Porter RS, Jones TV (2006) The Merck Manual of Diagnosis and Therapy. New Jersey: Merck Research Laboratories, Whitehouse Station. 3000 p.
[5]
Carter SK (1975) Adriamycin - a review. J Natl Cancer Inst 55: 1265–1274.
[6]
Arcamone F (1981) Doxorubicin: Anticancer Antibiotics. New York: Academic Press. 369 p.
[7]
Mortazavi S, Mosleh-Shirazi M, Tavassoli A, Taheri M, Bagheri Z, et al. (2011) A comparative study on the increased radioresistance to lethal doses of gamma rays after exposure to microwave radiation and oral intake of flaxseed oil. Iran J Radiat Res 9: 9–14.
[8]
Sannino A, Sarti M, Reddy SB, Prihoda TJ, Vijayalaxmi, et al (2009) Induction of adaptive response in human blood lymphocytes exposed to radiofrequency radiation. Radiat Res 171: 735–742.
[9]
Sannino A, Zeni O, Sarti M, Romeo S, Reddy SB, et al. (2011) Induction of adaptive response in human blood lymphocytes exposed to 900 MHz radiofrequency fields: influence of cell cycle. Int J Radiat Biol 87: 993–999.
[10]
Cao Y, Xu Q, Jin ZD, Zhang J, Lu MX, et al. (2010) Effects of 900-MHz microwave radiation on x-ray-induced damage to mouse hematopoietic system. J Toxicol Environ Health A 73: 507–513.
[11]
Cao Y, Xu Q, Jin ZD, Zhou Z, Nie JH, et al. (2011) Induction of adaptive response: Pre exposure of mice to 900 MHz radiofrequency fields reduces hematopoietic damage caused by subsequent exposure to ionizing radiation. Int J Radiat Biol 87: 720–728.
[12]
Burkhardt M, Pokovic K, Gnos M, Schmid T, Kuster N (1996) Numerical and experimental dosimetry of Petri dish exposure setups. Bioelectromagnetics 17: 483–493.
[13]
Cossarizza A, Baccarani Contri M, Kalashnikova G, Franceschi C (1993) A new method for the cytofluorimetric analysis of mitochondrial membrane potential using the J-aggregate forming lipophilic cation 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraeth？ylbenzimidazolcarbocyanineiodide (JC-1). Biochem Biophys Res Commun 197: 40–50.
[14]
Drexler HG, Quentmeier H, MacLeod RAF (2005) Cell line models of leukemia. Drug Discov Today: Disease Models 2: 51–56.
[15]
Rezaei PF, Fouladdel S, Cristofanon S, Ghaffari SM, Amin GR, et al. (2011) Comparative cellular and molecular analysis of cytotoxicity and apoptosis induction by doxorubicin and Baneh in human breast cancer T47D cells. Cytotechnology 63: 503–512.
[16]
Hanahan D, Weinberg RA (2011) Hallmarks of cancer: the next generation. Cell 144: 646–674.
[17]
Desagher S, Martinou JC (2000) Mitochondria as the central control point of apoptosis. Trends Cell Biol 10: 369–377.
[18]
Zamzami N, Marchetti P, Castedo M, Zanin C, Vayssiere JL, et al. (1995) Reduction in mitochondrial potential constitutes an early irreversible step of programmed lymphocyte death in vivo. J Exp Med 181: 1661–1672.
[19]
Kroemer G, Zamzami N, Susin SA (1997) Mitochondrial control of apoptosis. Immunol Today 18: 44–51.
[20]
Armstrong JS (2006) Mitochondrial membrane permeabilization: the sine qua non for cell death. Bioassays 28: 253–260.
[21]
Hajnóczky G, Davies E, Madesh M (2003) Calcium signaling and apoptosis. Biochem Biophys Res Commun 304: 445–454.
[22]
Xie SQ, Zhang ZQ, Hu GQ, Xu M, Ji BS (2008) HL-37, a novel anthracene derivative, induces Ca2+-mediated apoptosis in human breast cancer cells. Toxicology 254: 68–74.
[23]
Kluck RM, McDougall CA, Harmon BV, Halliday JW (1994) Calcium chelators induce apoptosis: evidence that raised intracellular ionized calcium is not essential for apoptosis. Biochim Biophys Acta 1223: 247–254.
[24]
Chakraborti S, Das S, Kar P, Ghosh B, Samanta K, et al. (2007) Calcium signaling phenomena in heart diseases: a perspective. Mol Cell Biochem 298: 1–40.
[25]
Delgado-Coello B, Trejo R, Mas-Oliva J (2006) Is there a specific role for the plasma membrane Ca2+-ATPase in the hepatocyte? Mol Cell Biochem 285: 1–15.
[26]
Persson BRR, Salford LG, Brun A (1997) Blood-brain barrier permeability in rats exposed to electromagnetic fields used in wireless communication. Wirel Netw 3: 455–461.
[27]
Nittby H, Grafstrom G, Tian DP, Malmgren L, Brun A, et al. (2008) Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation. Bioelectromagnetics 29: 219–232.
[28]
Verschaeve L, Juutilainen J, Lagroye I, Miyakoshi J, Saunders R, et al. (2010) In vitro and in vivo genotoxicity of radiofrequency fields. Mutat Res 705: 252–268.
[29]
Chen ZJ, Li XX, Lu YZ, Chen SJ, Jian LF, et al. (2010) Impact of 1.8-GHz radiofrequency radiation (RFR) on DNA damage and repair induced by doxorubicin in human B-cell lymphoblastoid cells. Mutat Res 695: 16–21.
[30]
Jiang B, Nie J, Zhou Z, Zhang J, Tong J, et al. (2012) Adaptive response in mice exposed to 900 MHz radiofrequency fields: primary DNA damage. PLoS One 7: e32040.
