Effect of adjuvant magnetic fields in radiotherapy on non-small-cell lung cancer cells in vitro.
OBJECTIVE
To explore sensitization and possible mechanisms of adjuvant magnetic fields (MFs) in radiotherapy (RT) of non-small-cell lung cancer.


METHODS
Human A549 lung adenocarcinoma cells were treated with MF, RT, and combined MF-RT. Colony-forming efficiency was calculated, cell cycle and apoptosis were measured, and changes in cell cycle- and apoptosis-related gene expression were measured by microarray.


RESULTS
A 0.5 T, 8 Hz stationary MF showed a duration-dependent inhibitory effect lasting for 1-4 hours. The MF-treated groups had significantly greater cell inhibition than did controls (P < 0.05). Surviving fractions and growth curves derived from colony-forming assay showed that the MF-only, RT-only, and MF-RT groups had inhibited cell growth; the MF-RT group showed a synergetic effect. Microarray of A549 cells exposed for 1 hour to MF showed that 19 cell cycle- and apoptosis-related genes had 2-fold upregulation and 40 genes had 2-fold downregulation. MF significantly arrested cells in G₂ and M phases, apparently sensitizing the cells to RT.


CONCLUSIONS
MF may inhibit A549 cells and can increase their sensitivity to RT, possibly by affecting cell cycle- and apoptosis-related signaling pathways.
Cancer Research Institute, Zhejiang Cancer Hospital, No. 38 Guangji Road, Hangzhou, Zhejiang 310022, China ; Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology, Hangzhou, Zhejiang 310022, China.
Jianguo
J
Feng
Huaying
H
Sheng
Chihong
C
Zhu
Hao
H
Jiang
Shenglin
S
Ma
D017209:Apoptosis / Q000528:radiation effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D059186:Chemoradiotherapy, Adjuvant; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects; D006801:Humans; D060526:Magnetic Fields; D011836:Radiation Tolerance / Q000528:radiation effects; D046888:Tissue Array Analysis