Exposure to ELF-pulse modulated X band microwaves increases in vitro human astrocytoma cell proliferation.
Common concern about the biological effects of electromagnetic fields (EMF) is increasing with the expansion of X-band microwaves (MW). The purpose of our work was to determine whether exposure to MW pulses in this range can induce toxic effects on human astrocytoma cells. Cultured astrocytoma cells (Clonetics line 1321N1) were submitted to 9.6 GHz carrier, 90% amplitude modulated by extremely low frequency (ELF)-EMF pulses inside a Gigahertz Transversal Electromagnetic Mode cell (GTEM-cell). Astrocytoma cultures were maintained inside a GTEM-incubator in standard culture conditions at 37+/-0.1 degrees C, 5% CO2, in a humidified atmosphere. Two experimental conditions were applied with field parameters respectively of: PW 100-120 ns; PRF 100-800 Hz; PRI 10-1.25 ms; power 0.34-0.60 mW; electric field strength 1.25-1.64 V/m; magnetic field peak amplitude 41.4-54.6 microOe. SAR was calculated to be 4.0 x 10-4 W/Kg. Astrocytoma samples were grown in a standard incubator. Reaching 70-80% confluence, cells were transferred to a GTEM-incubator. Experimental procedure included exposed human astrocytoma cells to MW for 15, 30, 60 min and 24 h and unexposed sham-control samples. Double blind method was applied. Our results showed that cytoskeleton proteins, cell morphology and viability were not modified. Statistically significant results showed increased cell proliferation rate under 24h MW exposure. Hsp-70 and Bcl-2 antiapoptotic proteins were observed in control and treated samples, while an increased expression of connexin 43 proteins was found in exposed samples. The implication of these results on increased proliferation is the subject of our current research.
Magnetobiology Laboratory, Department of Human Anatomy and Histology, School of Medicine, University of Zaragoza, Zaragoza, Spain. capercas@unizar.es
C
C
Pérez-Castejón
R N
RN
Pérez-Bruzón
M
M
Llorente
N
N
Pes
C
C
Lacasa
T
T
Figols
M
M
Lahoz
C
C
Maestú
A
A
Vera-Gil
A
A
Del Moral
M J
MJ
Azanza
D001254:Astrocytoma / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D006690:Bisbenzimidazole / Q000378:metabolism; D016923:Cell Death / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects*; D002478:Cells, Cultured; D004396:Coloring Agents / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D008872:Microwaves; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000528:radiation effects; D011419:Propidium / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014343:Trypan Blue / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism / Q000528:radiation effects
D004396:Coloring Agents; D005456:Fluorescent Dyes; D018840:HSP70 Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D014404:Tubulin; D011419:Propidium; D014343:Trypan Blue; D006690:Bisbenzimidazole