Effects of static magnetic field on human leukemic cell line HL-60 J. Sabo a, * , L. Mirossay b , L. Horovcak a , M. Sarissky b , A. Mirossay b , J. Mojzis b a Department of Medical Biophysics, Medical Faculty, P.J. Safarik University, Trieda SNP 1, 04011 Kosice, Slovak Republic b Department of Pharmacology, Medical Faculty, P.J. Safarik University, Trieda SNP 1, 04011 Kosice, Slovak Republic Received 1 June 2001; received in revised form 25 October 2001; accepted 6 November 2001 Abstract A number of structures with magnetic moments exists in living organisms that may be oriented by magnetic field. While most experimental efforts belong to the area of effects induced by weak and extremely low-frequency electromagnetic fields, we attempt to give an attention to the biological effects of strong static magnetic fields. The influence of static magnetic field (SMF) on metabolic activity of cells was examined. The metabolic activity retardation is observed in human leukemic cell line HL-60 exposed to 1-T SMF for 72 h. The retardation effect was observed as well as in the presence of the mixture of the antineoplastic drugs 5 fluorouracil, cisplatin, doxorubicin and vincristine. D 2002 Elsevier Science B.V. All rights reserved. Keywords: HL-60; Magnetic fields; Chemotherapy; Cytotoxicity 1. Introduction From one point of view, living organisms are electro- magnetic systems that use electromagnetic fields from protein folding and macromolecular interactions trough membrane functions to the propagation of information in nervous system. Interest in the interaction of electromag- netic field with living organisms has been triggered primar- ily from epidemiology studies, which have reported weak associations between magnetic field exposure and a variety of cancers. Therefore, research efforts were mainly focused on weak and extremely low-frequency fields. However, the present experiment is concerned with possible influence of relatively ‘‘strong’’ static magnetic field (SMF) on metabolic activity of cells. Concerning strong SMF, growing demand for the study of biological effects is generated by spreading magnetic resonance imaging system used for medical diag- nosis and the probable introduction of new technologies such as magnetically levitated trains. Electromagnetic fields have been used for decades in medical therapy, confirming that under certain conditions non-ionizing electromagnetic energy can influence physio- logical processes in organism. Coupling magnetic field ex- posure with possible chemotherapy of cancers is a new fascinating area that has been evolving in recent years. Current evidences suggest that cell processes can be influ- enced by the combination of magnetic fields and drugs. Exposure of mice by low-frequency pulsing electromagnetic field increased the bone marrow toxicity of cyclophospha- mide [1]. In an in vitro cell growth assay, carboplatin potency against human cancer cell lines A-431 and HT-29 increased after 1-h pulsed magnetic field (PMF) exposure with an average field strength of 0.525 mT. The potentiating effect was not observed with cisplatin. Daunomycin was potentiated only against HT-29 [2]. Cisplatin, carboplatin and doxorubicin had an increased tumoricidal effect when the whole organism of a mouse xenograft cancer model was exposed with the same field as it was mentioned above. The mean tumor volumes in mice treated with combination of drug and pulse magnetic field was 52%, 34% and 35% of that found in the respective cisplatin, carboplatin and dox- orubicin drug alone groups [3]. The modulating effects of magnetic field on the efficacy of cancer chemotherapy may find a particular role even in as serious problem as the resistance of tumor cells to many anticancer drugs. Exposure of KB-Ch-8-5-11, a multidrug resistant human carcinoma subline, which over-expresses P- glycoprotein and is resistant to colchicine, daunorubicin, doxorubicin, vinblastine and actinomycin D, to PMF- enhanced potency of daunorubicin only when PMF expo- 1567-5394/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII:S1567-5394(02)00027-0 * Corresponding author. Fax: +42-1-55-420253. E-mail address: grosiar@central.medic.upjs.sk (J. Sabo). www.elsevier.com/locate/bioelechem Bioelectrochemistry 56 (2002) 227 – 231