Abstract
Purpose: To explore the effects of power frequency magnetic fields (MF) on cell growth in prostate cancer, DU145, PC3, and LNCaP cells were examined in vitro.
Materials and methods: The cells were exposed to various intensities and durations of 60-Hz sinusoidal MF in combination with various serum concentrations in the media. To analyze MF effects on cell growth, cell counting, trypan blue exclusion assay, Western blot analysis, flow cytometry, enzyme-linked immunosorbent assay (ELISA), semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), fluorescence microscopy, and spectrofluorometry were used.
Results: MF exposure induced significant cell growth inhibition and apoptosis in an intensity- and time-dependent manner, in which cell cycle arrest, cleaved Caspase-3, and reactive oxygen species (ROS) increased. Pretreatment with a Caspase-3 inhibitor or antioxidant, N-acetyl-L-cysteine (NAC), significantly attenuated MF-induced cell growth inhibition and cell death. Media replacement experiments failed to show any notable change in the MF effects.
Conclusions: These results demonstrate 60-Hz sinusoidal MF-activated cell growth inhibition of prostate cancer in vitro. Apoptosis together with cell cycle arrest were the dominant causes of the MF-elicited cell growth inhibition, mediated by MF-induced ROS. These results suggest that a possibility of using 60-Hz MF in radiation therapy of prostate cancer could usefully be investigated.
Abbreviations | ||
ANOVA | = | Analysis of variance |
Bax | = | Bcl-2-associated X protein |
Bcl-2 | = | B-cell lymphoma 2 protein |
BMP | = | Bone morphogenic protein |
Carboxy-H2DCFDA | = | 5-(and-6)-Carboxy-2′,7′-dichlorodihydrofluorescein diacetate |
Con | = | Control |
DEVDfmk | = | Asp (OMe)-Glu (OMe)-Val-Asp (OMe)-fluoromethyl ketone |
DMSO | = | Dimethyl sulfoxide |
EGF | = | Epidermal growth factor |
ELISA | = | Enzyme-linked immunosorbent assay |
MF | = | Magnetic field |
NAC | = | N-acetyl-l-cysteine |
PBS | = | Phosphate-buffered saline |
PKC | = | Protein kinase C |
PMSF | = | Phenylmethylsulfonyl fluoride |
ROS | = | Reactive oxygen species |
RPMI | = | Roswell Park Memorial Institute medium |
RT-PCR | = | Reverse transcriptase-polymerase chain reaction |
SDS | = | Sodium dodecyl sulfate |
SEM | = | Standard error of the mean |
TGF-β | = | Transforming growth factor-β |
TPA | = | 12-O-tetradecanoylphorbol-13-acetate |
Abbreviations | ||
ANOVA | = | Analysis of variance |
Bax | = | Bcl-2-associated X protein |
Bcl-2 | = | B-cell lymphoma 2 protein |
BMP | = | Bone morphogenic protein |
Carboxy-H2DCFDA | = | 5-(and-6)-Carboxy-2′,7′-dichlorodihydrofluorescein diacetate |
Con | = | Control |
DEVDfmk | = | Asp (OMe)-Glu (OMe)-Val-Asp (OMe)-fluoromethyl ketone |
DMSO | = | Dimethyl sulfoxide |
EGF | = | Epidermal growth factor |
ELISA | = | Enzyme-linked immunosorbent assay |
MF | = | Magnetic field |
NAC | = | N-acetyl-l-cysteine |
PBS | = | Phosphate-buffered saline |
PKC | = | Protein kinase C |
PMSF | = | Phenylmethylsulfonyl fluoride |
ROS | = | Reactive oxygen species |
RPMI | = | Roswell Park Memorial Institute medium |
RT-PCR | = | Reverse transcriptase-polymerase chain reaction |
SDS | = | Sodium dodecyl sulfate |
SEM | = | Standard error of the mean |
TGF-β | = | Transforming growth factor-β |
TPA | = | 12-O-tetradecanoylphorbol-13-acetate |