Mitochondrial hyperpolarization and cytochrome-c release in microwave-exposed MCF-7 cells.
This study examines the effects of a 2.1-GHz WCDMA-modulated microwave (MW) radiation on apoptotic activity and mitochondrial membrane potential (ΔΨm) in MCF-7 cells. The cells were exposed to the MW at a specific absorption rate (SAR) of 0.528 W/kg for 4 or 24 h. The antiproliferative effect of MW exposure was determined by the MTT test. Cytochrome-c and p53 levels were determined by an ELISA method. The relative ΔΨm was analysed by JC-1 staining using flow cytometer. Apoptotic rate of the cells was measured by Annexin-V-FITC staining. All assays were performed after certain time of incubations (15 min-4 h) following MW exposure. MW-exposed cells showed a significant decrease in viability when compared to unexposed cells. A significantly larger decrease was observed after longer exposure. The percentage of apoptotic cells, amount of cytochrome-c, and relative ΔΨm were significantly higher in MW-exposed cells. The percent of apoptotic cells and relative ΔΨm in 24 h MW-exposed group was significantly higher than those in 4 h MW-exposed group. However, no significant change was observed in p53 levels. These results demonstrated that exposure to 2.1-GHz WCDMA-modulated MW radiation caused hyperpolarization of mitochondria that in turn induced apoptosis in MCF-7 cells.
Department of Biophysics, Faculty of Medicine, Gazi University, Ankara, Turkey. mericarda@yahoo.com.
Meric A
MA
Esmekaya
Ayşe G
AG
Canseven
Handan
H
Kayhan
Mehmet Z
MZ
Tuysuz
Bahriye
B
Sirav
Nesrin
N
Seyhan
D017209:Apoptosis / Q000502:physiology / Q000528:radiation effects*; D045304:Cytochromes c / Q000096:biosynthesis*; D004307:Dose-Response Relationship, Radiation; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D061986:MCF-7 Cells; D053078:Membrane Potential, Mitochondrial / Q000502:physiology* / Q000528:radiation effects; D008872:Microwaves; D008928:Mitochondria / Q000502:physiology* / Q000528:radiation effects; D011829:Radiation Dosage
D045304:Cytochromes c