title: Influence of 1 and 25 Hz, 1.5 mT magnetic fields on antitumor drug potency in a human adenocarcinoma cell line.
abstract: The resistance of tumor cells to antineoplastic agents is a major obstacle during cancer chemotherapy. Many authors have observed that some exposure protocols to pulsed electromagnetic fields (PEMF) can alter the efficacy of anticancer drugs; nevertheless, the observations are not clear. We have evaluated whether a group of PEMF pulses (1.5 mT peak, repeated at 1 and 25 Hz) produces alterations of drug potency on a multidrug resistant human colon adenocarcinoma (HCA) cell line, HCA-2/1(cch). The experiments were performed including (a) exposures to drug and PEMF exposure for 1 h at the same time, (b) drug exposure for 1 h, and then exposure to PEMF for the next 2 days (2 h/day). Drugs used were vincristine (VCR), mitomycin C (MMC), and cisplatin. Cell viability was measured by the neutral red stain cytotoxicity test. The results obtained were: (a) The 1 Hz PEMF increased VCR cytotoxicity (P < 0.01), exhibiting 6.1% of survival at 47.5 microg/ml, the highest dose for which sham exposed groups showed a 19.8% of survival. For MMC at 47.5 microg/ml, the % of survival changed significantly from 19.2% in sham exposed groups to 5.3% using 25 Hz (P < 0.001). Cisplatin showed a significant reduction in the % of survival (44.2-39.1%, P < 0.05) at 25 Hz and 47.5 microg/ml, and (b) Minor significant alterations were observed after nonsimultaneous exposure of cells to PEMF and drug. The data indicate that PEMF can induce modulation of cytostatic agents in HCA-2/1(cch), with an increased effect when PEMF was applied at the same time as the drug. The type of drug, dose, frequency, and duration of PEMF exposure could influence this modulation.
authors.affiliation: Laboratory of Radiobiology, Department of Radiology and Physical Medicine, Faculty of Medicine, University of Málaga, Teatinos, Málaga, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Ruiz-Gómez
authors.forename: L
authors.initials: L
authors.lastname: de la Peña
authors.forename: M I
authors.initials: MI
authors.lastname: Prieto-Barcia
authors.forename: J M
authors.initials: JM
authors.lastname: Pastor
authors.forename: L
authors.initials: L
authors.lastname: Gil
authors.forename: M
authors.initials: M
authors.lastname: Martínez-Morillo
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000528:radiation effects; D017209:Apoptosis / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002945:Cisplatin / Q000008:administration & dosage / Q000528:radiation effects; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D018432:Drug Resistance, Multiple / Q000528:radiation effects*; D004574:Electromagnetic Fields; D006801:Humans; D008280:Magnetics / Q000627:therapeutic use; D016685:Mitomycin / Q000008:administration & dosage / Q000528:radiation effects; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D014750:Vincristine / Q000008:administration & dosage / Q000528:radiation effects
chemical_list: D000970:Antineoplastic Agents; D016685:Mitomycin; D014750:Vincristine; D002945:Cisplatin